Crystal structure of a calcium(II)–pyrrolo­quinoline quinone (PQQ) complex outside a protein environment

Lumpe, H.; Mayer, P.; Daumann, L.J.

doi:10.1107/S2053229620014278

research papers

STRUCTURAL
CHEMISTRY

ISSN: 2053-2296

Volume 76| Part 12| December 2020| Pages 1051-1056

https://doi.org/10.1107/S2053229620014278

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Crystal structure of a calcium(II)–pyrroloquinoline quinone (PQQ) complex outside a protein environment¹

Henning Lumpe,^a Peter Mayer ^a and Lena J. Daumann ^a ^*

^aDepartment of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Munich, Bavaria 81377, Germany
^*Correspondence e-mail: lena.daumann@cup.lmu.de

Edited by Y. Ohgo, Teikyo University, Japan (Received 10 September 2020; accepted 27 October 2020; online 5 November 2020)

Pyrroloquinoline quinone (PQQ) is an important cofactor of calcium- and lanthanide-dependent alcohol dehydrogenases, and has been known for over 30 years. Crystal structures of Ca–MDH enzymes (MDH is methanol dehydrogenase) have been known for some time; however, crystal structures of PQQ with biorelevant metal ions have been lacking in the literature for decades. We report here the first crystal structure analysis of a Ca–PQQ complex outside the protein environment, namely, poly[[undecaaquabis(μ-4,5-dioxo-4,5-dihydro-1H-pyrrolo[2,3-f]quinoline-2,7,9-tricarboxylato)tricalcium(II)] dihydrate], {[Ca₃(C₁₄H₃N₂O₈)₂(H₂O)₁₁]·2H₂O}_n. The complex crystallized as Ca₃PQQ₂·13H₂O with Ca²⁺ in three different positions and PQQ³⁻, including an extensive hydrogen-bond network. Similarities and differences to the recently reported structure with biorelevant europium (Eu₂PQQ₂) are discussed.

Keywords: pyrroloquinoline quinone; calcium; PQQ; methanol dehydrogenase; crystal structure.

CCDC reference: 2019890

1. Introduction

Pyrroloquinoline quinone (PQQ) is the redox cofactor of glucose dehydrogenase enzymes and alcohol dehydrogenases. In particular, the methanol dehydrogenase (MDH) enzymes, which catalyze the oxidation of methanol for the energy household of many methano- and methylotrophic microorganisms, have attracted attention recently. For proper functionality, a metal ion is needed, which acts as a Lewis acid and which is coordinated by PQQ and several amino acids in the enzymatic active site (Fig. 1). The Ca-dependent MDH, encoded by the mxaF gene, was first discovered by Anthony & Zatman (1964a ,b ).

Figure 1
The structure of the active site from Ca-dependent MDH (PDB code 1w6s).

After the structure of MDH was elucidated in 1978–79 (Duine et al., 1978 ; Westerling et al., 1979 ; Salisbury et al., 1979 ), the cofactor attracted much attention in the following years, with articles published concerning its total synthesis (Corey & Tramontano, 1981 ), redox chemistry (Eckert et al., 1982 ), metal coordination (Noar et al., 1985 ) and small-molecule interaction (van Koningsveld et al., 1985 ). Itoh and co-workers published several articles presenting the interaction of PQQ with Ca and other alkaline earth metals (Itoh et al., 1997 , 1998 ), and the synthesis of model compounds, mimicking the active site of MDH (Itoh et al., 2000 ). Those publications contributed to a better understanding of the functionality and reactivity of PQQ. However, no crystal structures were presented in those studies, which would reveal in-depth structural information of PQQ–metal interactions. While no Ca–PQQ structure has been published to date, in addition, few other crystal structures exist for PQQ with other metals. Outside of the Ca–MDH network (Blake et al., 1994 ; Williams et al., 2005 ), several structures were published with sodium (Ishida et al., 1989 ; Ikemoto et al., 2012 ; Ikemoto et al., 2017 ), with PQQ structural analogs and iron (Tommasi et al., 1995 ), with copper and terpyridine (terpy) as co-ligand (Nakamura et al., 1994 ), with copper and triphenylphosphine (Wanner et al., 1999 ), with ruthenium and terpy (Mitome et al., 2015 ), and with ruthenium, silver and terpy (Mitome et al., 2013 ). In 2014, Pol et al. reported a new kind of MDH, found in the extremophile Methylacidiphilum fumariolicum SolV (SolV), which is native to volcanic mudpots close to the Solfatara crater in Italy (Pol et al., 2014 ). This MDH turned out to be strictly dependent on lanthanides (Pol et al., 2014; Lumpe et al., 2018 ; Bogart et al., 2015 ). While SolV was originally thought to be a biological curiosity, more and more organisms in all kinds of ecosystems were found to be lanthanide dependent in the following years, not restricted to such extreme environments like SolV (Keltjens et al., 2014 ; Ramachandran & Walsh, 2015 ; Taubert et al., 2015 ). This also pushed lanthanide bioinorganic chemistry as a new and emerging scientific field with several reviews published (Skovran & Martinez-Gomez, 2015 ; Cheisson & Schelter, 2019 ; Chistoserdova, 2019 ; Cotruvo, 2019 ; Daumann, 2019 ; Picone & Op den Camp, 2019 ; Semrau et al., 2018 ). Recently, also, the first crystal structure of a europium–PQQ complex outside the MDH network was published through a collaborative effort and was reported as an Eu₂PQQ₂ structure (Lumpe et al., 2020 ) (Fig. 2). In light of those advances and the still scarce structural information available about PQQ–metal interactions, we present here the first crystal structure of a Ca–PQQ complex without the need of structural PQQ analogs or additional co-ligands. The molecular formula of the complex is Ca₃PQQ₂·13H₂O.

Figure 2
The crystal structure of the inversion-symmetric Eu₂PQQ₂ complex. The CIF is taken from Lumpe et al. (2020

). Displacement ellipsoids are drawn at the 50% probability level. [Symmetry code: (i) −x + 1, −y + 1, −z + 1.]

2. Experimental

2.1. Materials

CaCl₂·2H₂O (99%) was purchased from VWR. Na₂PQQ·H₂O was extracted from Doctor's Best Science-Based Nutrition BioPQQ capsules, as described previously (Lumpe & Daumann, 2019 ). Milli-Q-grade water (pH 5.5), obtained from a Millipore Synergy UV system from Merck (Darmstadt, Germany), was used for all experiments.

2.2. Crystal growth and analysis

Na₂PQQ·H₂O (32.8 mg, 0.08 mmol) was dissolved in H₂O (12 ml). CaCl₂·2H₂O (2.0 equiv., 23.6 mg, 0.16 mmol) was added as a solid. The metal addition led to precipitation of a pale-grey–brown solid, which was centrifuged, removed and analyzed as a 1:1 PQQ–Ca complex, as described in our previous article (Lumpe & Daumann, 2019). From the supernatant, consisting of a highly diluted aqueous mixture of Na₂PQQ and CaCl₂, small dark crystals, suitable for X-ray crystallography, grew over a period of several months. To obtain more crystalline material of better quality, a procedure from our recent publication (Lumpe et al., 2020) was implemented. Na₂PQQ·H₂O (24.2 mg, 61.8 µmol) was completely dissolved in H₂O (4 ml) at 80 °C in an ultrasonic bath. CaCl₂·2H₂O (27.3 mg, 185.4 µmol, 3 equiv.) was dissolved in a small amount of water (0.2 ml) and was added to the Na₂PQQ solution at 80 °C, which caused precipitation of a grey–brown solid. The mixture was placed directly in a drying oven at 80 °C, which was then switched off and the reaction mixture allowed to cool slowly. After 1 d, small dark crystals had grown between the bulk precipitate. The crystals grew in size over the next few days while consuming the surrounding bulk precipitate. Crystals suitable for X-ray diffraction analysis were then picked out of the reaction mixture. The crystal used for analysis was selected in paraffin oil to prevent dehydration and then placed and measured on a Mitegen Microloop. The crystals obtained from both methods showed the same structure depicted in Fig. 3.

Figure 3
(a) The asymmetric unit of Ca₃PQQ₂·13H₂O. (b) A strand along [ $[\overline{1}]$ 11] consisting of inversion-symmetric Ca₂PQQ₂²⁻ pairs. Here, for clarity, all water molecules, except for that involved in intra-pair hydrogen bonds (green arrows), have been omitted. For symmetry codes, see Table 2

IR (diamond ATR, neat): $[\~\nu]$ /cm⁻¹ 3643–2746 (w, broad), 1923–1714 (w, broad), 1686 (w), 1658 (w), 1605 (s), 1577 (m), 1553 (m), 1536 (m), 1498 (m), 1426 (w), 1400 (m), 1348 (s), 1277 (m), 1246 (m), 1191 (m), 1151 (m), 1132 (w), 1086 (w), 1027 (w), 972 (w), 951 (w), 926 (w), 868 (w), 824 (w), 767 (w), 719 (w), 700 (w), 669 (w). Elemental analysis (CHN) calculated (%) for Ca₃PQQ₂·11H₂O or C₂₈H₂₈Ca₃N₄O₂₇: C 34.57, H 2.90, N 5.76; found: C 34.30, H 3.20, N 6.06. Crystals were picked out of the reaction mixture and then dried for 1 d on filter paper prior to elemental analysis.

2.3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. Four reflections have been omitted from the refinement. Three of them are hidden by the beam stop and show no intensity. A further omitted reflection of higher order (090) has a significantly higher F_o² (63.72) compared to its F_c² (1.09). This behaviour is observed quite often for reflections of higher order when multigraded X-ray mirrors are used as monochromators. All C-bound H atoms have been calculated in ideal geometry riding on their parent atoms, while the O- and N-bound H atoms were refined freely. Full details of the refinement strategy can be found in the embedded instruction file in the CIF.

Table 1
Experimental details

Crystal data
Chemical formula	[Ca₃(C₁₄H₃N₂O₈)₂(H₂O)₁₁]·2H₂O
M_r	1008.81
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	109
a, b, c (Å)	6.9363 (3), 15.9791 (7), 16.9786 (7)
α, β, γ (°)	90.844 (1), 93.106 (1), 98.296 (2)
V (Å³)	1858.93 (14)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.56
Crystal size (mm)	0.10 × 0.02 × 0.01

Data collection
Diffractometer	Bruker D8 Venture TXS
Absorption correction	Multi-scan (SADABS; Bruker, 2016 )
T_min, T_max	0.88, 0.99
No. of measured, independent and observed [I > 2σ(I)] reflections	33048, 8166, 7023
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.641

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.072, 1.04
No. of reflections	8166
No. of parameters	689
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.28
Computer programs: APEX3 (Bruker, 2016), SAINT (Bruker, 2017 ), SHELXT2014 (Sheldrick, 2015 a), SHELXL2018 (Sheldrick, 2015b) and ORTEP-3 (Farrugia, 2012 ).

3. Results and discussion

3.1. Investigation of PQQ–Ca complexation

In our previous article, PQQ–metal complexes were reported with the trivalent lanthanides La³⁺, Eu³⁺ and Lu³⁺, and with Ca²⁺ (Lumpe & Daumann, 2019). Regardless of the excess of added metal salt, 1:1 complexes were identified by elemental analysis. While no further structural information could be provided in that study, we were recently able to verify the proposed stoichiometry by the crystal structure of an Eu–PQQ complex with the net formula Eu₂PQQ₂·12H₂O (Lumpe et al., 2020). The Eu³⁺ ion is coordinated by PQQ in the same fashion as in MDH, with participation of N2, O4 and O5, in addition to the participation of O1 (Fig. 2). The latter residue is not utilized in the enzyme for metal coordination.

From a similar experimental approach using Ca²⁺ instead of Eu³⁺, single crystals suitable for X-ray analysis were grown over a period of several days. Fig. 3 illustrates the composition of the asymmetric unit: the charges of two triply deprotonated PQQ units are balanced by three Ca²⁺ ions supplemented by 13 water molecules. The structural motif depicted in Fig. 2 – the formation of binuclear units by means of two PQQ ligands acting as linkers between the metal centres – is realized in Ca₃PQQ₂·13H₂O in a comparable fashion for two of the three Ca ions (Ca1 and Ca3). Ca1 is coordinated by PQQ in a similar fashion to Eu; however, the coordination sphere is completed by a carboxylate group of a nearby pyridine moiety of PQQ (instead of a carboxylate of a pyrrole ring). Ca3, on the other hand, uses the same pocket and residues as Eu; however, this interaction is assisted by a hydrogen bond of a Ca3-bound water molecule to the carboxylate group of the pyrrole ring (Fig. 3b, green arrows). In the structure, these two types of alternating Ca1 and Ca3 units are connected via Ca1 into strands along [ $[\overline{1}]$ 11]. The charge of the Ca₂PQQ₂ unit is balanced by Ca2, which is coordinated solely by water molecules and carboxylate groups, however, never in the biologically relevant ONO pocket of PQQ. All N—H and O—H donor groups are involved in classical hydrogen bonds with either carboxylate groups, keto groups or water molecules, acting as acceptors establishing a three-dimensional network (see Table 2 for hydrogen-bond details).

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H2⋯O8	0.86 (2)	2.01 (2)	2.7232 (19)	139.6 (19)
N3—H4⋯O16	0.86 (2)	1.83 (2)	2.6163 (19)	151 (2)
O17—H171⋯O10ⁱⁱⁱ	0.85 (3)	1.91 (3)	2.7543 (18)	170 (3)
O17—H172⋯O1	0.86 (3)	2.08 (3)	2.9287 (19)	170 (2)
O18—H181⋯O28	0.88 (3)	1.82 (3)	2.681 (2)	166 (2)
O18—H182⋯O1^iv	0.84 (3)	1.97 (3)	2.8107 (19)	176 (3)
O19—H191⋯O20ⁱⁱ	0.81 (3)	2.10 (3)	2.8789 (19)	161 (3)
O19—H192⋯O5ⁱ	0.85 (3)	1.89 (3)	2.7350 (18)	174 (3)
O20—H201⋯O11^v	0.82 (3)	2.00 (3)	2.8221 (18)	173 (3)
O20—H202⋯O2^vi	0.84 (3)	1.94 (3)	2.7620 (18)	169 (3)
O21—H211⋯O29ⁱⁱⁱ	0.80 (3)	2.05 (3)	2.845 (2)	173 (3)
O21—H212⋯O16	0.85 (3)	1.90 (3)	2.7320 (18)	163 (3)
O22—H221⋯O19^vi	0.76 (3)	2.26 (3)	2.958 (2)	152 (3)
O22—H222⋯O6^vii	0.87 (3)	1.83 (3)	2.6985 (19)	175 (3)
O23—H231⋯O3^viii	0.76 (3)	2.10 (3)	2.8398 (19)	164 (3)
O23—H232⋯O9ⁱⁱⁱ	0.83 (3)	1.90 (3)	2.7217 (19)	169 (3)
O24—H241⋯O7^ix	0.81 (3)	2.03 (3)	2.8040 (19)	163 (3)
O24—H242⋯O29	0.82 (3)	1.93 (3)	2.750 (2)	172 (3)
O25—H251⋯O13^ix	0.85 (3)	2.02 (3)	2.8578 (18)	168 (3)
O25—H252⋯O3^viii	0.81 (3)	2.41 (3)	3.0258 (19)	133 (2)
O25—H252⋯O4^viii	0.81 (3)	2.28 (3)	3.0405 (18)	155 (3)
O26—H261⋯O27^x	0.86 (3)	2.11 (3)	2.9018 (19)	154 (3)
O26—H262⋯O13^ix	0.80 (3)	2.06 (3)	2.8506 (19)	170 (3)
O27—H271⋯O25^iv	0.85 (3)	2.08 (3)	2.9022 (19)	164 (3)
O27—H272⋯O9^v	0.83 (3)	1.99 (3)	2.8125 (18)	171 (2)
O28—H281⋯O10^v	0.89 (4)	1.88 (4)	2.721 (2)	159 (3)
O28—H282⋯O26^x	0.83 (4)	2.59 (3)	3.098 (2)	121 (3)
O29—H291⋯O6^ix	0.84 (3)	1.85 (3)	2.6582 (19)	160 (3)
O29—H292⋯O11	0.79 (3)	2.27 (3)	3.021 (2)	159 (3)
O29—H292⋯O12	0.79 (3)	2.40 (3)	2.7789 (19)	110 (2)
Symmetry codes: (i) ; (ii) ; (iii) ; (iv) x+1, y, z; (v) ; (vi) ; (vii) ; (viii) ; (ix) ; (x) .

Interestingly, while the elemental analysis of the initially precipitated (amorphous) solid showed a 1:1 Ca–PQQ stoichiometry (Lumpe & Daumann, 2019), the present structure from slowly crystallized material reveals a network of three different Ca²⁺ ions and two differently-coordinated PQQ anionic ligands, resulting in a 3:2 stoichiometry. Also, in the Ca–PQQ structure, both PQQ molecules coordinate in the same fashion as in the MDH enzyme (Fig. 1), in addition to the participation of several carboxylate groups. One of the PQQ ligands coordinates to calcium with the participation of all three carboxylate groups: Ca1 via O8, N2, O5 and O4, and Ca2 via O1 and O2 in a bidentate manner. The second PQQ molecule coordinates with only two of the three carboxylate groups and coordinates Ca1 with O14, Ca2 with O15 and Ca3 with N4, O12 and O13. In total, 13 water molecules are present in the crystal structure, of which 11 directly coordinate to atoms Ca1–Ca3 and two water molecules (O28 and O29) have no direct coordination partners. Interestingly, elemental analysis of the dried crystalline material fits best to only 11 water molecules, most likely due to the disappearance of the two noncoordinating water molecules during the drying process. Ca1 and Ca2 show pentagonal–bipyramidal geometries, with coordination numbers (CNs) of 7 and Ca3 shows a distorted geometry with a CN of 8. All metal-to-ligand bond lengths and angles of Ca₃PQQ₂ are given in Table 3, in addition to the values for Eu₂PQQ₂. The known PQQ–water adduct (diol in C5 position), which is formed to some extent in aqueous solution (Dekker et al., 1982 ), is not present in the complex, and this is in line with all known crystal structures of PQQ, to the best of our knowledge.

Table 3
Selected bond lengths (Å) of the Ca₃PQQ₂·13H₂O complex in comparison with the previously reported Eu₂PQQ₂·12H₂O structure

For symmetry data for Eu₂PQQ₂·12H₂O, see Lumpe et al. (2020).

Ca₃PQQ₂·13H₂O		Eu₂PQQ₂·12H₂O
Ca1ⁱ—O4	2.5928 (12)	Eu1—O4	2.584 (2)
Ca1ⁱ—N2	2.5069 (14)	Eu1—N2	2.648 (2)
Ca1ⁱ—O5	2.3784 (12)	Eu1—O5	2.440 (2)
Ca1—O14	2.2514 (12)	Eu1—O1	2.409 (2)
Ca1—O8	2.3137 (12)	Eu1—O_water (5 bonds)	2.389 (2)–2.464 (2)
Ca1—O17	2.3694 (13)
Ca1—O18	2.3145 (14)	Ca3—O12	2.5703 (12)
Ca2ⁱⁱ—O1	2.4812 (12)	Ca3—N4	2.5460 (14)
Ca2ⁱⁱ—O2	2.5279 (12)	Ca3—O13	2.3963 (12)
Ca2—O15	2.3522 (12)	Ca3—O23	2.4362 (14)
Ca2—O19	2.3894 (14)	Ca3—O24	2.3607 (13)
Ca2—O20	2.4382 (13)	Ca3—O25	2.5787 (14)
Ca2—O21	2.3824 (14)	Ca3—O26	2.3962 (14)
Ca2—O22	2.3383 (14)	Ca3—O27	2.4924 (14)
Symmetry codes: (i) −x + 1, −y + 1, −z + 1; (ii) x − 1, y, z.

In the Eu₂PQQ₂ complex, the Eu ions are coordinated in a similar fashion by PQQ. The bonds to Eu are up to 0.141 Å longer than to Ca1 and Ca3. The CN of Eu in the complex is 9, which corresponds to an ionic radius of 1.12 Å according to Shannon (1976 ), while the ionic radius of Ca is 1.06 Å for a CN of 7 and 1.12 Å for a CN of 8. Therefore, the larger bond lengths to Eu can hardly be explained by different ionic radii, which are overall similar, but by differences in the CNs and different participation in coordination of a second PQQ molecule.

The IR spectra of the precipitated Ca–PQQ amorphous solid, Eu₂PQQ₂ and Ca₃PQQ₂ crystals were recorded and compared (Fig. 4). The spectra can be roughly divided into two areas. While PQQ C=O stretching vibrations of the carboxylate and quinone groups absorb in the range 1750–1600 cm⁻¹ (Zhejiang Hisun Pharmaceutical Co. Ltd, 2020 ), the peaks with smaller wavenumbers are largely related to PQQ lattice vibrations. While the heights of the large absorption bands in the range 3600–2600 cm⁻¹ are a direct result of the different amounts and coordination modes of cocrystallized water, the differences in the area 1750–1550 cm⁻¹ further indicate the different coordination modes already depicted in the crystal structures.

Figure 4
Normalized IR absorption spectra of the Ca₃PQQ₂ complex in black, the 1:1 Ca–PQQ precipitate in grey and the Eu₂PQQ₂ complex in blue. Inset: close-up of the PQQ-related IR absorption peaks.

4. Conclusion

We present here the first crystal structure of PQQ with the biologically relevant metal ion calcium. The complex consists of PQQ and the metal ion alone, unlike previously reported structures with other metal ions. Those complexes often needed additional co-ligands, which limited the use of the structures for comparison with the biologically active site. However, in particular, the use of methylated PQQMe₃ (with all three carboxyl groups esterified) prevented participation of (nonbiogenic) carboxyl groups in complexation. This is not the case in the presented structure, where calcium is coordinated by PQQ in the same pocket as in MDH, in addition to further carboxyl-group participation, spanning a three-dimensional coordination network. However, considering the few crystal structures of PQQ complexes reported over the years, we are confident that the presented structure will help to better explain the coordination behaviour of PQQ outside the MDH enzyme and help guide the design of mononuclear model complexes for these fascinating enzymes.

Supporting information

CCDC reference: 2019890

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2053229620014278/yo3076sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2053229620014278/yo3076Isup2.hkl

Computing details top

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2017); data reduction: SAINT (Bruker, 2017); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: SHELXL2018 (Sheldrick, 2015b).

Poly[[undecaaquabis(µ-4,5-dioxo-4,5-dihydro-1H-pyrrolo[2,3-f]quinoline-2,7,9-tricarboxylato)tricalcium(II)] dihydrate] top

Crystal data top

[Ca₃(C₁₄H₃N₂O₈)₂(H₂O)₁₁]·2H₂O	Z = 2
M_r = 1008.81	F(000) = 1040
Triclinic, P1	D_x = 1.802 Mg m⁻³
a = 6.9363 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 15.9791 (7) Å	Cell parameters from 9854 reflections
c = 16.9786 (7) Å	θ = 2.7–27.1°
α = 90.844 (1)°	µ = 0.56 mm⁻¹
β = 93.106 (1)°	T = 109 K
γ = 98.296 (2)°	Rod, brown
V = 1858.93 (14) Å³	0.10 × 0.02 × 0.01 mm

Data collection top

Bruker D8 Venture TXS diffractometer	8166 independent reflections
Radiation source: rotating anode (TXS), Bruker TXS	7023 reflections with I > 2σ(I)
Focusing mirrors monochromator	R_int = 0.043
Detector resolution: 7.3910 pixels mm^-1	θ_max = 27.1°, θ_min = 2.9°
mix of phi and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2016)	k = −20→20
T_min = 0.88, T_max = 0.99	l = −21→21
33048 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.072	w = 1/[σ²(F_o²) + (0.0198P)² + 1.5469P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
8166 reflections	Δρ_max = 0.39 e Å⁻³
689 parameters	Δρ_min = −0.28 e Å⁻³
0 restraints

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. H(C) constr, H(O,N) refall

The X-ray intensity data of Ca₃PQQ₂.13H₂O were measured on a Bruker D8 Venture TXS system equipped with a multilayer mirror monochromator and an Mo Kα rotating anode X-ray tube (λ = 0.71073 Å). The frames were integrated with the Bruker SAINT software package (Bruker, 2012). Data were corrected for absorption effects using the multi-scan method (SADABS; Sheldrick, 1996). The structure was solved and refined using the Bruker SHELXTL software package (Sheldrick, 2015).

The figures have been drawn at the 50% ellipsoid probability level (Farrugia, 2012). CCDC reference number 2019890 contains the supplementary crystallographic data for this compound. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via https://www.ccdc.cam.ac.uk/structures/.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	−0.0551 (2)	0.15843 (11)	0.45568 (10)	0.0109 (3)
C2	0.0302 (2)	0.23438 (11)	0.50409 (10)	0.0109 (3)
C3	0.0676 (3)	0.24585 (11)	0.58398 (10)	0.0118 (3)
H3	0.044989	0.204050	0.622953	0.014*
C4	0.1464 (2)	0.33192 (10)	0.59713 (10)	0.0106 (3)
C5	0.2090 (3)	0.37785 (11)	0.67020 (10)	0.0112 (3)
C6	0.2975 (2)	0.47079 (11)	0.66033 (10)	0.0101 (3)
C7	0.2934 (2)	0.50827 (10)	0.57991 (10)	0.0093 (3)
C8	0.3650 (2)	0.63184 (10)	0.51260 (10)	0.0092 (3)
C9	0.2907 (2)	0.59109 (10)	0.44200 (10)	0.0097 (3)
H9A	0.286091	0.622433	0.394992	0.012*
C10	0.2233 (2)	0.50464 (11)	0.43996 (10)	0.0095 (3)
C11	0.2231 (2)	0.46006 (10)	0.51131 (10)	0.0085 (3)
C12	0.1552 (2)	0.37072 (11)	0.52343 (10)	0.0095 (3)
C13	0.4498 (2)	0.72499 (10)	0.51886 (10)	0.0096 (3)
C14	0.1589 (2)	0.46574 (10)	0.35822 (10)	0.0092 (3)
C15	0.8745 (2)	−0.19201 (10)	−0.04981 (10)	0.0101 (3)
C16	0.8334 (2)	−0.10395 (10)	−0.06229 (10)	0.0091 (3)
C17	0.8475 (2)	−0.05705 (10)	−0.12909 (10)	0.0097 (3)
H17	0.881560	−0.075253	−0.179338	0.012*
C18	0.8015 (2)	0.02382 (11)	−0.10895 (10)	0.0096 (3)
C19	0.7972 (2)	0.09630 (11)	−0.15653 (10)	0.0107 (3)
C20	0.7502 (2)	0.17425 (11)	−0.11221 (9)	0.0095 (3)
C21	0.6921 (2)	0.16752 (10)	−0.02863 (9)	0.0083 (3)
C22	0.5978 (2)	0.24379 (10)	0.07438 (9)	0.0089 (3)
C23	0.6126 (2)	0.17681 (10)	0.12466 (10)	0.0099 (3)
H23	0.584351	0.182354	0.178455	0.012*
C24	0.6684 (2)	0.10142 (10)	0.09720 (10)	0.0088 (3)
C25	0.7027 (2)	0.09418 (10)	0.01609 (9)	0.0077 (3)
C26	0.7593 (2)	0.02301 (10)	−0.02847 (9)	0.0085 (3)
C27	0.5362 (2)	0.32716 (10)	0.09921 (9)	0.0093 (3)
C28	0.6930 (2)	0.03531 (11)	0.15995 (10)	0.0098 (3)
N1	0.0833 (2)	0.31067 (9)	0.46858 (9)	0.0101 (3)
N2	0.3651 (2)	0.59035 (9)	0.58038 (8)	0.0090 (3)
H2	0.084 (3)	0.3176 (13)	0.4186 (13)	0.015 (5)*
N3	0.7800 (2)	−0.05460 (9)	−0.00212 (8)	0.0086 (3)
N4	0.6427 (2)	0.23938 (9)	−0.00095 (8)	0.0086 (3)
H4	0.748 (4)	−0.0682 (15)	0.0449 (15)	0.030 (6)*
O1	−0.06633 (18)	0.16506 (7)	0.38093 (7)	0.0128 (3)
O2	−0.11654 (18)	0.09119 (7)	0.48944 (7)	0.0136 (3)
O3	0.2007 (2)	0.34951 (8)	0.73630 (7)	0.0169 (3)
O4	0.37574 (18)	0.51241 (7)	0.71690 (7)	0.0127 (3)
O5	0.52358 (18)	0.75182 (7)	0.58571 (7)	0.0120 (2)
O6	0.4405 (2)	0.76768 (8)	0.45848 (7)	0.0164 (3)
O7	0.06140 (18)	0.50722 (8)	0.31437 (7)	0.0130 (3)
O8	0.21731 (18)	0.39705 (7)	0.34077 (7)	0.0125 (3)
O9	0.87842 (18)	−0.21856 (8)	0.01978 (7)	0.0136 (3)
O10	0.90747 (19)	−0.23220 (8)	−0.11050 (7)	0.0151 (3)
O11	0.8269 (2)	0.10239 (8)	−0.22705 (7)	0.0171 (3)
O12	0.76438 (18)	0.24116 (7)	−0.14539 (7)	0.0125 (3)
O13	0.53948 (18)	0.38361 (7)	0.04724 (7)	0.0123 (3)
O14	0.48287 (18)	0.33522 (7)	0.16717 (7)	0.0122 (2)
O15	0.74044 (19)	0.06498 (8)	0.22821 (7)	0.0151 (3)
O16	0.66342 (19)	−0.04197 (7)	0.14100 (7)	0.0134 (3)
O17	0.2228 (2)	0.21676 (8)	0.26500 (8)	0.0155 (3)
H171	0.173 (4)	0.2165 (17)	0.2180 (17)	0.042 (8)*
H172	0.130 (4)	0.1974 (16)	0.2943 (15)	0.032 (7)*
O18	0.7774 (2)	0.29042 (9)	0.29412 (8)	0.0191 (3)
H181	0.851 (4)	0.3119 (16)	0.2567 (16)	0.035 (7)*
H182	0.823 (4)	0.2513 (19)	0.3180 (17)	0.048 (8)*
O19	0.4610 (2)	0.08055 (9)	0.37538 (8)	0.0166 (3)
H191	0.352 (4)	0.0580 (17)	0.3624 (15)	0.038 (8)*
H192	0.460 (4)	0.1327 (18)	0.3851 (15)	0.037 (7)*
O20	1.07981 (19)	−0.01918 (8)	0.36462 (8)	0.0138 (3)
H201	1.099 (4)	−0.0466 (18)	0.3251 (18)	0.049 (9)*
H202	1.095 (4)	−0.0465 (17)	0.4056 (17)	0.041 (8)*
O21	0.6842 (2)	−0.11057 (9)	0.28711 (8)	0.0191 (3)
H211	0.601 (4)	−0.1501 (18)	0.2910 (15)	0.037 (8)*
H212	0.679 (4)	−0.0997 (17)	0.2380 (17)	0.042 (8)*
O22	0.6175 (2)	−0.07062 (9)	0.45523 (8)	0.0218 (3)
H221	0.616 (4)	−0.0567 (18)	0.4984 (18)	0.048 (9)*
H222	0.563 (4)	−0.1236 (19)	0.4537 (16)	0.047 (8)*
O23	0.3675 (2)	0.26664 (9)	−0.13577 (9)	0.0155 (3)
H231	0.307 (4)	0.2808 (16)	−0.1708 (16)	0.033 (7)*
H232	0.291 (4)	0.2457 (17)	−0.1028 (16)	0.039 (8)*
O24	0.6812 (2)	0.39272 (9)	−0.22016 (8)	0.0182 (3)
H241	0.768 (4)	0.4241 (17)	−0.2383 (15)	0.036 (8)*
H242	0.678 (4)	0.3485 (19)	−0.2459 (16)	0.043 (8)*
O25	0.34868 (19)	0.45056 (8)	−0.11501 (8)	0.0143 (3)
H251	0.367 (4)	0.5014 (18)	−0.0984 (16)	0.040 (8)*
H252	0.336 (4)	0.4522 (17)	−0.1628 (18)	0.043 (8)*
O26	0.7643 (2)	0.51788 (8)	−0.07189 (8)	0.0177 (3)
H261	0.865 (5)	0.5441 (19)	−0.0459 (18)	0.054 (9)*
H262	0.684 (4)	0.5490 (17)	−0.0700 (15)	0.035 (7)*
O27	0.9930 (2)	0.37549 (9)	−0.04551 (8)	0.0152 (3)
H271	1.082 (4)	0.3989 (18)	−0.0735 (16)	0.043 (8)*
H272	1.021 (4)	0.3284 (17)	−0.0340 (14)	0.031 (7)*
O28	0.9475 (2)	0.36727 (10)	0.17111 (9)	0.0212 (3)
H281	1.013 (5)	0.333 (2)	0.1450 (19)	0.067 (10)*
H282	1.030 (5)	0.409 (2)	0.182 (2)	0.069 (11)*
O29	0.6350 (2)	0.24139 (9)	−0.30317 (9)	0.0210 (3)
H291	0.640 (4)	0.2383 (16)	−0.3524 (16)	0.034 (7)*
H292	0.711 (4)	0.2134 (17)	−0.2848 (16)	0.039 (8)*
Ca1	0.47149 (5)	0.33132 (2)	0.29935 (2)	0.00881 (8)
Ca2	0.75264 (5)	0.02017 (2)	0.35950 (2)	0.00913 (8)
Ca3	0.63978 (5)	0.37014 (2)	−0.08465 (2)	0.00934 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0099 (8)	0.0095 (8)	0.0132 (8)	0.0014 (7)	0.0000 (6)	−0.0006 (6)
C2	0.0104 (8)	0.0087 (8)	0.0134 (8)	−0.0004 (7)	0.0022 (6)	0.0016 (6)
C3	0.0136 (8)	0.0088 (8)	0.0126 (8)	−0.0004 (7)	0.0013 (7)	0.0009 (6)
C4	0.0111 (8)	0.0075 (8)	0.0126 (8)	−0.0004 (6)	−0.0009 (7)	0.0013 (6)
C5	0.0119 (8)	0.0090 (8)	0.0126 (8)	0.0011 (7)	−0.0006 (7)	0.0010 (6)
C6	0.0095 (8)	0.0113 (8)	0.0096 (8)	0.0026 (7)	0.0007 (6)	−0.0005 (6)
C7	0.0081 (8)	0.0078 (8)	0.0119 (8)	0.0010 (6)	0.0006 (6)	0.0012 (6)
C8	0.0093 (8)	0.0074 (8)	0.0109 (8)	0.0009 (6)	0.0011 (6)	0.0008 (6)
C9	0.0099 (8)	0.0101 (8)	0.0090 (8)	0.0013 (7)	0.0001 (6)	0.0016 (6)
C10	0.0071 (8)	0.0105 (8)	0.0108 (8)	0.0013 (6)	0.0004 (6)	−0.0003 (6)
C11	0.0068 (8)	0.0077 (8)	0.0108 (8)	0.0003 (6)	0.0004 (6)	−0.0002 (6)
C12	0.0071 (8)	0.0093 (8)	0.0117 (8)	0.0005 (6)	0.0005 (6)	−0.0013 (6)
C13	0.0094 (8)	0.0081 (8)	0.0110 (8)	0.0002 (6)	0.0019 (6)	−0.0007 (6)
C14	0.0083 (8)	0.0085 (8)	0.0096 (8)	−0.0034 (6)	0.0022 (6)	−0.0003 (6)
C15	0.0061 (8)	0.0084 (8)	0.0152 (8)	−0.0010 (6)	−0.0001 (6)	0.0000 (6)
C16	0.0072 (8)	0.0095 (8)	0.0103 (8)	0.0008 (6)	−0.0006 (6)	−0.0024 (6)
C17	0.0080 (8)	0.0093 (8)	0.0115 (8)	0.0009 (6)	0.0000 (6)	−0.0024 (6)
C18	0.0090 (8)	0.0105 (8)	0.0091 (8)	0.0012 (6)	−0.0012 (6)	−0.0011 (6)
C19	0.0117 (8)	0.0113 (8)	0.0091 (8)	0.0023 (7)	−0.0001 (6)	−0.0011 (6)
C20	0.0094 (8)	0.0107 (8)	0.0082 (8)	0.0014 (6)	−0.0012 (6)	0.0001 (6)
C21	0.0070 (8)	0.0081 (8)	0.0091 (8)	−0.0007 (6)	−0.0009 (6)	−0.0010 (6)
C22	0.0086 (8)	0.0083 (8)	0.0093 (8)	0.0001 (6)	−0.0005 (6)	−0.0001 (6)
C23	0.0112 (8)	0.0102 (8)	0.0079 (8)	0.0003 (7)	0.0003 (6)	−0.0005 (6)
C24	0.0071 (8)	0.0095 (8)	0.0093 (8)	−0.0002 (6)	−0.0011 (6)	0.0004 (6)
C25	0.0054 (7)	0.0079 (8)	0.0093 (8)	0.0002 (6)	−0.0011 (6)	0.0009 (6)
C26	0.0064 (8)	0.0090 (8)	0.0098 (8)	0.0004 (6)	−0.0008 (6)	0.0003 (6)
C27	0.0090 (8)	0.0087 (8)	0.0093 (8)	−0.0008 (6)	−0.0012 (6)	−0.0009 (6)
C28	0.0100 (8)	0.0106 (8)	0.0089 (8)	0.0006 (7)	0.0024 (6)	0.0017 (6)
N1	0.0122 (7)	0.0086 (7)	0.0087 (7)	−0.0003 (6)	0.0002 (6)	−0.0008 (6)
N2	0.0079 (7)	0.0079 (7)	0.0112 (7)	0.0008 (5)	0.0001 (5)	0.0004 (5)
N3	0.0103 (7)	0.0074 (7)	0.0080 (7)	0.0004 (6)	0.0005 (5)	0.0004 (5)
N4	0.0086 (7)	0.0084 (7)	0.0088 (7)	0.0015 (5)	−0.0003 (5)	0.0003 (5)
O1	0.0168 (6)	0.0104 (6)	0.0104 (6)	−0.0005 (5)	0.0003 (5)	0.0006 (5)
O2	0.0190 (7)	0.0086 (6)	0.0117 (6)	−0.0022 (5)	0.0001 (5)	0.0010 (5)
O3	0.0247 (7)	0.0132 (6)	0.0115 (6)	−0.0004 (5)	−0.0031 (5)	0.0037 (5)
O4	0.0152 (6)	0.0110 (6)	0.0111 (6)	−0.0003 (5)	−0.0018 (5)	−0.0002 (5)
O5	0.0172 (6)	0.0082 (6)	0.0096 (6)	−0.0005 (5)	−0.0016 (5)	−0.0004 (5)
O6	0.0270 (7)	0.0093 (6)	0.0108 (6)	−0.0036 (5)	−0.0029 (5)	0.0029 (5)
O7	0.0153 (6)	0.0127 (6)	0.0108 (6)	0.0022 (5)	−0.0022 (5)	0.0006 (5)
O8	0.0133 (6)	0.0115 (6)	0.0126 (6)	0.0020 (5)	0.0008 (5)	−0.0026 (5)
O9	0.0154 (6)	0.0116 (6)	0.0142 (6)	0.0027 (5)	0.0016 (5)	0.0039 (5)
O10	0.0199 (7)	0.0110 (6)	0.0150 (6)	0.0052 (5)	−0.0014 (5)	−0.0032 (5)
O11	0.0295 (7)	0.0152 (6)	0.0085 (6)	0.0080 (6)	0.0053 (5)	0.0013 (5)
O12	0.0185 (6)	0.0098 (6)	0.0095 (6)	0.0028 (5)	0.0014 (5)	0.0024 (5)
O13	0.0193 (7)	0.0092 (6)	0.0096 (6)	0.0051 (5)	0.0026 (5)	0.0015 (5)
O14	0.0161 (6)	0.0120 (6)	0.0088 (6)	0.0022 (5)	0.0024 (5)	−0.0006 (5)
O15	0.0236 (7)	0.0125 (6)	0.0092 (6)	0.0029 (5)	−0.0010 (5)	0.0009 (5)
O16	0.0206 (7)	0.0088 (6)	0.0108 (6)	0.0020 (5)	0.0022 (5)	0.0016 (5)
O17	0.0171 (7)	0.0154 (7)	0.0123 (6)	−0.0029 (5)	−0.0003 (6)	−0.0010 (5)
O18	0.0175 (7)	0.0242 (8)	0.0178 (7)	0.0091 (6)	0.0042 (6)	0.0068 (6)
O19	0.0143 (7)	0.0103 (7)	0.0247 (7)	0.0012 (6)	0.0002 (6)	−0.0026 (5)
O20	0.0164 (7)	0.0133 (6)	0.0116 (6)	0.0024 (5)	0.0001 (5)	−0.0013 (5)
O21	0.0323 (8)	0.0115 (7)	0.0108 (7)	−0.0053 (6)	−0.0008 (6)	0.0016 (5)
O22	0.0384 (9)	0.0119 (7)	0.0127 (7)	−0.0064 (6)	0.0073 (6)	−0.0008 (5)
O23	0.0165 (7)	0.0166 (7)	0.0128 (7)	0.0001 (6)	−0.0001 (6)	0.0041 (5)
O24	0.0285 (8)	0.0130 (7)	0.0132 (6)	0.0013 (6)	0.0066 (6)	0.0013 (6)
O25	0.0204 (7)	0.0112 (7)	0.0114 (7)	0.0028 (5)	−0.0005 (5)	−0.0005 (5)
O26	0.0158 (7)	0.0117 (6)	0.0255 (7)	0.0033 (6)	−0.0026 (6)	−0.0011 (6)
O27	0.0145 (7)	0.0110 (6)	0.0204 (7)	0.0026 (5)	0.0013 (5)	0.0024 (5)
O28	0.0222 (8)	0.0179 (7)	0.0239 (7)	0.0028 (6)	0.0040 (6)	−0.0008 (6)
O29	0.0337 (9)	0.0179 (7)	0.0101 (7)	0.0007 (6)	−0.0029 (6)	0.0014 (5)
Ca1	0.01094 (16)	0.00795 (16)	0.00727 (16)	0.00073 (13)	0.00000 (12)	−0.00028 (12)
Ca2	0.01122 (17)	0.00735 (16)	0.00825 (16)	−0.00045 (13)	0.00028 (12)	0.00033 (12)
Ca3	0.01280 (17)	0.00742 (16)	0.00802 (16)	0.00195 (13)	0.00126 (13)	0.00085 (12)

Geometric parameters (Å, º) top

C1—O2	1.256 (2)	C28—O15	1.255 (2)
C1—O1	1.274 (2)	C28—O16	1.256 (2)
C1—C2	1.486 (2)	N1—H2	0.86 (2)
C1—Ca2ⁱ	2.8519 (17)	N2—Ca1ⁱⁱ	2.5069 (14)
C2—C3	1.372 (2)	N3—H4	0.86 (2)
C2—N1	1.379 (2)	N4—Ca3	2.5460 (14)
C3—C4	1.415 (2)	O1—Ca2ⁱ	2.4812 (12)
C3—H3	0.9500	O2—Ca2ⁱ	2.5279 (12)
C4—C12	1.405 (2)	O4—Ca1ⁱⁱ	2.5928 (12)
C4—C5	1.445 (2)	O5—Ca1ⁱⁱ	2.3784 (12)
C5—O3	1.217 (2)	O8—Ca1	2.3137 (12)
C5—C6	1.538 (2)	O12—Ca3	2.5703 (12)
C6—O4	1.216 (2)	O13—Ca3	2.3963 (12)
C6—C7	1.500 (2)	O14—Ca1	2.2514 (12)
C7—N2	1.334 (2)	O15—Ca2	2.3522 (12)
C7—C11	1.411 (2)	O17—Ca1	2.3694 (13)
C8—N2	1.337 (2)	O17—H171	0.85 (3)
C8—C9	1.393 (2)	O17—H172	0.86 (3)
C8—C13	1.520 (2)	O18—Ca1	2.3145 (14)
C9—C10	1.392 (2)	O18—H181	0.88 (3)
C9—H9A	0.9500	O18—H182	0.84 (3)
C10—C11	1.414 (2)	O19—Ca2	2.3894 (14)
C10—C14	1.529 (2)	O19—H191	0.81 (3)
C11—C12	1.458 (2)	O19—H192	0.85 (3)
C12—N1	1.350 (2)	O20—Ca2	2.4382 (13)
C13—O6	1.244 (2)	O20—H201	0.82 (3)
C13—O5	1.262 (2)	O20—H202	0.84 (3)
C14—O7	1.241 (2)	O21—Ca2	2.3824 (14)
C14—O8	1.260 (2)	O21—H211	0.80 (3)
C15—O10	1.255 (2)	O21—H212	0.85 (3)
C15—O9	1.261 (2)	O22—Ca2	2.3383 (14)
C15—C16	1.491 (2)	O22—H221	0.76 (3)
C16—C17	1.369 (2)	O22—H222	0.87 (3)
C16—N3	1.380 (2)	O23—Ca3	2.4362 (14)
C17—C18	1.416 (2)	O23—H231	0.76 (3)
C17—H17	0.9500	O23—H232	0.83 (3)
C18—C26	1.413 (2)	O24—Ca3	2.3607 (13)
C18—C19	1.425 (2)	O24—H241	0.81 (3)
C19—O11	1.229 (2)	O24—H242	0.82 (3)
C19—C20	1.530 (2)	O25—Ca3	2.5787 (14)
C20—O12	1.210 (2)	O25—H251	0.85 (3)
C20—C21	1.497 (2)	O25—H252	0.81 (3)
C21—N4	1.331 (2)	O26—Ca3	2.3962 (14)
C21—C25	1.414 (2)	O26—H261	0.86 (3)
C22—N4	1.336 (2)	O26—H262	0.80 (3)
C22—C23	1.391 (2)	O27—Ca3	2.4924 (14)
C22—C27	1.517 (2)	O27—H271	0.85 (3)
C23—C24	1.399 (2)	O27—H272	0.83 (3)
C23—H23	0.9500	O28—H281	0.89 (4)
C24—C25	1.416 (2)	O28—H282	0.83 (4)
C24—C28	1.531 (2)	O29—H291	0.84 (3)
C25—C26	1.468 (2)	O29—H292	0.79 (3)
C26—N3	1.349 (2)	Ca2—H212	2.77 (3)
C27—O14	1.241 (2)	Ca3—H242	2.79 (3)
C27—O13	1.270 (2)

O2—C1—O1	122.57 (16)	Ca2—O20—H202	108.7 (19)
O2—C1—C2	119.37 (15)	H201—O20—H202	111 (3)
O1—C1—C2	118.05 (15)	Ca2—O21—H211	131.1 (19)
O2—C1—Ca2ⁱ	62.38 (9)	Ca2—O21—H212	108.2 (18)
O1—C1—Ca2ⁱ	60.30 (9)	H211—O21—H212	104 (2)
C2—C1—Ca2ⁱ	174.96 (12)	Ca2—O22—H221	122 (2)
C3—C2—N1	108.35 (15)	Ca2—O22—H222	133.1 (18)
C3—C2—C1	131.39 (16)	H221—O22—H222	105 (3)
N1—C2—C1	120.24 (15)	Ca3—O23—H231	115.6 (19)
C2—C3—C4	106.75 (15)	Ca3—O23—H232	116.1 (18)
C2—C3—H3	126.6	H231—O23—H232	108 (3)
C4—C3—H3	126.6	Ca3—O24—H241	125.7 (19)
C12—C4—C3	107.73 (15)	Ca3—O24—H242	113.0 (19)
C12—C4—C5	122.41 (15)	H241—O24—H242	104 (3)
C3—C4—C5	129.85 (15)	Ca3—O25—H251	114.2 (18)
O3—C5—C4	126.34 (16)	Ca3—O25—H252	106 (2)
O3—C5—C6	118.97 (15)	H251—O25—H252	106 (3)
C4—C5—C6	114.67 (14)	Ca3—O26—H261	131 (2)
O4—C6—C7	120.52 (15)	Ca3—O26—H262	115.5 (19)
O4—C6—C5	120.10 (15)	H261—O26—H262	105 (3)
C7—C6—C5	119.34 (14)	Ca3—O27—H271	122.3 (18)
N2—C7—C11	124.30 (15)	Ca3—O27—H272	112.4 (17)
N2—C7—C6	113.14 (14)	H271—O27—H272	107 (2)
C11—C7—C6	122.55 (15)	H281—O28—H282	103 (3)
N2—C8—C9	121.27 (15)	H291—O29—H292	107 (3)
N2—C8—C13	115.32 (14)	O14—Ca1—O8	110.58 (4)
C9—C8—C13	123.41 (15)	O14—Ca1—O18	83.93 (5)
C10—C9—C8	120.33 (15)	O8—Ca1—O18	160.87 (5)
C10—C9—H9A	119.8	O14—Ca1—O17	81.08 (5)
C8—C9—H9A	119.8	O8—Ca1—O17	84.33 (5)
C9—C10—C11	118.83 (15)	O18—Ca1—O17	110.98 (5)
C9—C10—C14	115.60 (14)	O14—Ca1—O5ⁱⁱ	147.08 (4)
C11—C10—C14	125.56 (15)	O8—Ca1—O5ⁱⁱ	92.68 (4)
C7—C11—C10	116.10 (15)	O18—Ca1—O5ⁱⁱ	79.85 (5)
C7—C11—C12	115.64 (14)	O17—Ca1—O5ⁱⁱ	78.35 (4)
C10—C11—C12	128.24 (15)	O14—Ca1—N2ⁱⁱ	139.18 (5)
N1—C12—C4	106.95 (15)	O8—Ca1—N2ⁱⁱ	80.01 (4)
N1—C12—C11	127.93 (15)	O18—Ca1—N2ⁱⁱ	80.87 (5)
C4—C12—C11	125.07 (15)	O17—Ca1—N2ⁱⁱ	139.74 (5)
O6—C13—O5	126.02 (15)	O5ⁱⁱ—Ca1—N2ⁱⁱ	65.71 (4)
O6—C13—C8	117.71 (14)	O14—Ca1—O4ⁱⁱ	79.80 (4)
O5—C13—C8	116.27 (14)	O8—Ca1—O4ⁱⁱ	80.92 (4)
O7—C14—O8	126.49 (15)	O18—Ca1—O4ⁱⁱ	89.87 (5)
O7—C14—C10	116.37 (15)	O17—Ca1—O4ⁱⁱ	149.89 (4)
O8—C14—C10	117.05 (14)	O5ⁱⁱ—Ca1—O4ⁱⁱ	128.25 (4)
O10—C15—O9	126.01 (16)	N2ⁱⁱ—Ca1—O4ⁱⁱ	62.59 (4)
O10—C15—C16	115.89 (15)	O22—Ca2—O15	148.18 (5)
O9—C15—C16	118.07 (15)	O22—Ca2—O21	78.62 (5)
C17—C16—N3	108.57 (14)	O15—Ca2—O21	77.75 (5)
C17—C16—C15	129.10 (15)	O22—Ca2—O19	81.60 (5)
N3—C16—C15	122.28 (15)	O15—Ca2—O19	87.27 (5)
C16—C17—C18	106.85 (15)	O21—Ca2—O19	110.91 (5)
C16—C17—H17	126.6	O22—Ca2—O20	98.71 (5)
C18—C17—H17	126.6	O15—Ca2—O20	98.27 (5)
C26—C18—C17	107.48 (14)	O21—Ca2—O20	80.94 (5)
C26—C18—C19	122.96 (15)	O19—Ca2—O20	167.84 (5)
C17—C18—C19	129.55 (15)	O22—Ca2—O1ⁱⁱⁱ	127.21 (5)
O11—C19—C18	127.61 (16)	O15—Ca2—O1ⁱⁱⁱ	81.48 (4)
O11—C19—C20	118.19 (15)	O21—Ca2—O1ⁱⁱⁱ	151.55 (5)
C18—C19—C20	114.20 (14)	O19—Ca2—O1ⁱⁱⁱ	87.10 (5)
O12—C20—C21	121.02 (15)	O20—Ca2—O1ⁱⁱⁱ	83.06 (4)
O12—C20—C19	118.84 (15)	O22—Ca2—O2ⁱⁱⁱ	75.46 (5)
C21—C20—C19	120.12 (14)	O15—Ca2—O2ⁱⁱⁱ	133.97 (4)
N4—C21—C25	124.89 (15)	O21—Ca2—O2ⁱⁱⁱ	145.39 (5)
N4—C21—C20	112.30 (14)	O19—Ca2—O2ⁱⁱⁱ	87.61 (5)
C25—C21—C20	122.68 (15)	O20—Ca2—O2ⁱⁱⁱ	80.74 (4)
N4—C22—C23	121.19 (15)	O1ⁱⁱⁱ—Ca2—O2ⁱⁱⁱ	52.58 (4)
N4—C22—C27	114.53 (14)	O22—Ca2—C1ⁱⁱⁱ	101.03 (5)
C23—C22—C27	124.27 (15)	O15—Ca2—C1ⁱⁱⁱ	107.87 (5)
C22—C23—C24	120.98 (15)	O21—Ca2—C1ⁱⁱⁱ	162.54 (5)
C22—C23—H23	119.5	O19—Ca2—C1ⁱⁱⁱ	86.13 (5)
C24—C23—H23	119.5	O20—Ca2—C1ⁱⁱⁱ	81.88 (5)
C23—C24—C25	118.04 (15)	O1ⁱⁱⁱ—Ca2—C1ⁱⁱⁱ	26.49 (4)
C23—C24—C28	115.57 (14)	O2ⁱⁱⁱ—Ca2—C1ⁱⁱⁱ	26.12 (4)
C25—C24—C28	126.36 (14)	O22—Ca2—H212	94.6 (6)
C21—C25—C24	115.99 (15)	O15—Ca2—H212	60.7 (6)
C21—C25—C26	114.23 (14)	O21—Ca2—H212	17.0 (6)
C24—C25—C26	129.67 (15)	O19—Ca2—H212	107.9 (6)
N3—C26—C18	106.92 (14)	O20—Ca2—H212	84.2 (6)
N3—C26—C25	127.74 (15)	O1ⁱⁱⁱ—Ca2—H212	137.7 (6)
C18—C26—C25	125.34 (15)	O2ⁱⁱⁱ—Ca2—H212	160.4 (6)
O14—C27—O13	124.61 (15)	C1ⁱⁱⁱ—Ca2—H212	160.5 (6)
O14—C27—C22	118.79 (14)	O24—Ca3—O26	83.48 (5)
O13—C27—C22	116.58 (14)	O24—Ca3—O13	161.79 (5)
O15—C28—O16	125.31 (15)	O26—Ca3—O13	85.73 (5)
O15—C28—C24	114.92 (14)	O24—Ca3—O23	82.50 (5)
O16—C28—C24	119.76 (14)	O26—Ca3—O23	144.90 (5)
C12—N1—C2	110.20 (15)	O13—Ca3—O23	98.26 (5)
C12—N1—H2	124.5 (14)	O24—Ca3—O27	96.15 (5)
C2—N1—H2	124.9 (14)	O26—Ca3—O27	75.13 (5)
C7—N2—C8	119.04 (14)	O13—Ca3—O27	95.21 (4)
C7—N2—Ca1ⁱⁱ	123.03 (11)	O23—Ca3—O27	138.35 (5)
C8—N2—Ca1ⁱⁱ	117.70 (11)	O24—Ca3—N4	132.11 (5)
C26—N3—C16	110.18 (14)	O26—Ca3—N4	137.02 (5)
C26—N3—H4	119.6 (16)	O13—Ca3—N4	64.53 (4)
C16—N3—H4	129.8 (16)	O23—Ca3—N4	73.39 (5)
C21—N4—C22	118.67 (14)	O27—Ca3—N4	77.41 (5)
C21—N4—Ca3	122.66 (11)	O24—Ca3—O12	70.98 (4)
C22—N4—Ca3	118.65 (11)	O26—Ca3—O12	134.27 (5)
C1—O1—Ca2ⁱ	93.21 (10)	O13—Ca3—O12	126.46 (4)
C1—O2—Ca2ⁱ	91.50 (10)	O23—Ca3—O12	69.44 (4)
C6—O4—Ca1ⁱⁱ	120.35 (11)	O27—Ca3—O12	70.85 (4)
C13—O5—Ca1ⁱⁱ	124.78 (10)	N4—Ca3—O12	62.01 (4)
C14—O8—Ca1	146.93 (11)	O24—Ca3—O25	81.28 (5)
C20—O12—Ca3	121.20 (11)	O26—Ca3—O25	73.38 (5)
C27—O13—Ca3	125.58 (10)	O13—Ca3—O25	81.59 (4)
C27—O14—Ca1	161.86 (11)	O23—Ca3—O25	72.78 (5)
C28—O15—Ca2	139.74 (11)	O27—Ca3—O25	148.49 (5)
Ca1—O17—H171	115.5 (18)	N4—Ca3—O25	127.07 (4)
Ca1—O17—H172	125.2 (16)	O12—Ca3—O25	135.26 (4)
H171—O17—H172	107 (2)	O24—Ca3—H242	15.8 (6)
Ca1—O18—H181	117.1 (16)	O26—Ca3—H242	98.7 (6)
Ca1—O18—H182	129 (2)	O13—Ca3—H242	168.8 (6)
H181—O18—H182	113 (3)	O23—Ca3—H242	72.2 (6)
Ca2—O19—H191	125.4 (19)	O27—Ca3—H242	95.9 (6)
Ca2—O19—H192	123.7 (18)	N4—Ca3—H242	116.6 (6)
H191—O19—H192	109 (3)	O12—Ca3—H242	56.6 (6)
Ca2—O20—H201	112 (2)	O25—Ca3—H242	89.7 (6)

O2—C1—C2—C3	4.2 (3)	C27—C22—C23—C24	179.30 (15)
O1—C1—C2—C3	−177.26 (18)	C22—C23—C24—C25	−2.2 (2)
O2—C1—C2—N1	−174.51 (15)	C22—C23—C24—C28	175.81 (15)
O1—C1—C2—N1	4.0 (2)	N4—C21—C25—C24	−3.8 (2)
N1—C2—C3—C4	−0.1 (2)	C20—C21—C25—C24	171.68 (15)
C1—C2—C3—C4	−178.94 (18)	N4—C21—C25—C26	179.55 (15)
C2—C3—C4—C12	−0.2 (2)	C20—C21—C25—C26	−5.0 (2)
C2—C3—C4—C5	179.25 (18)	C23—C24—C25—C21	4.9 (2)
C12—C4—C5—O3	177.69 (17)	C28—C24—C25—C21	−172.84 (15)
C3—C4—C5—O3	−1.7 (3)	C23—C24—C25—C26	−179.05 (16)
C12—C4—C5—C6	−3.6 (2)	C28—C24—C25—C26	3.2 (3)
C3—C4—C5—C6	176.96 (17)	C17—C18—C26—N3	0.23 (19)
O3—C5—C6—O4	7.4 (3)	C19—C18—C26—N3	−179.13 (15)
C4—C5—C6—O4	−171.33 (16)	C17—C18—C26—C25	−179.41 (15)
O3—C5—C6—C7	−174.98 (16)	C19—C18—C26—C25	1.2 (3)
C4—C5—C6—C7	6.2 (2)	C21—C25—C26—N3	−179.48 (16)
O4—C6—C7—N2	−5.9 (2)	C24—C25—C26—N3	4.4 (3)
C5—C6—C7—N2	176.54 (14)	C21—C25—C26—C18	0.1 (2)
O4—C6—C7—C11	173.13 (16)	C24—C25—C26—C18	−176.01 (16)
C5—C6—C7—C11	−4.4 (2)	N4—C22—C27—O14	176.56 (15)
N2—C8—C9—C10	−3.1 (3)	C23—C22—C27—O14	−4.9 (2)
C13—C8—C9—C10	177.06 (15)	N4—C22—C27—O13	−2.0 (2)
C8—C9—C10—C11	3.0 (2)	C23—C22—C27—O13	176.54 (15)
C8—C9—C10—C14	−175.77 (15)	C23—C24—C28—O15	−28.3 (2)
N2—C7—C11—C10	−2.8 (3)	C25—C24—C28—O15	149.54 (17)
C6—C7—C11—C10	178.32 (15)	C23—C24—C28—O16	150.92 (16)
N2—C7—C11—C12	178.55 (15)	C25—C24—C28—O16	−31.3 (2)
C6—C7—C11—C12	−0.4 (2)	C4—C12—N1—C2	−0.58 (19)
C9—C10—C11—C7	−0.2 (2)	C11—C12—N1—C2	−178.32 (16)
C14—C10—C11—C7	178.43 (15)	C3—C2—N1—C12	0.5 (2)
C9—C10—C11—C12	178.31 (16)	C1—C2—N1—C12	179.42 (15)
C14—C10—C11—C12	−3.1 (3)	C11—C7—N2—C8	2.7 (3)
C3—C4—C12—N1	0.49 (19)	C6—C7—N2—C8	−178.26 (14)
C5—C4—C12—N1	−179.02 (16)	C11—C7—N2—Ca1ⁱⁱ	−171.66 (12)
C3—C4—C12—C11	178.31 (16)	C6—C7—N2—Ca1ⁱⁱ	7.34 (19)
C5—C4—C12—C11	−1.2 (3)	C9—C8—N2—C7	0.3 (2)
C7—C11—C12—N1	−179.28 (16)	C13—C8—N2—C7	−179.89 (15)
C10—C11—C12—N1	2.2 (3)	C9—C8—N2—Ca1ⁱⁱ	175.00 (12)
C7—C11—C12—C4	3.4 (2)	C13—C8—N2—Ca1ⁱⁱ	−5.19 (19)
C10—C11—C12—C4	−175.13 (17)	C18—C26—N3—C16	−0.16 (19)
N2—C8—C13—O6	−175.07 (15)	C25—C26—N3—C16	179.48 (16)
C9—C8—C13—O6	4.7 (3)	C17—C16—N3—C26	0.02 (19)
N2—C8—C13—O5	4.8 (2)	C15—C16—N3—C26	177.55 (15)
C9—C8—C13—O5	−175.37 (16)	C25—C21—N4—C22	−0.5 (2)
C9—C10—C14—O7	−42.5 (2)	C20—C21—N4—C22	−176.42 (14)
C11—C10—C14—O7	138.90 (17)	C25—C21—N4—Ca3	177.66 (12)
C9—C10—C14—O8	134.37 (16)	C20—C21—N4—Ca3	1.78 (18)
C11—C10—C14—O8	−44.3 (2)	C23—C22—N4—C21	3.7 (2)
O10—C15—C16—C17	−8.1 (3)	C27—C22—N4—C21	−177.79 (14)
O9—C15—C16—C17	170.08 (16)	C23—C22—N4—Ca3	−174.62 (12)
O10—C15—C16—N3	174.93 (15)	C27—C22—N4—Ca3	3.93 (18)
O9—C15—C16—N3	−6.9 (2)	O2—C1—O1—Ca2ⁱ	3.95 (18)
N3—C16—C17—C18	0.13 (18)	C2—C1—O1—Ca2ⁱ	−174.56 (14)
C15—C16—C17—C18	−177.18 (16)	O1—C1—O2—Ca2ⁱ	−3.87 (17)
C16—C17—C18—C26	−0.22 (19)	C2—C1—O2—Ca2ⁱ	174.62 (14)
C16—C17—C18—C19	179.08 (17)	C7—C6—O4—Ca1ⁱⁱ	1.8 (2)
C26—C18—C19—O11	−178.07 (17)	C5—C6—O4—Ca1ⁱⁱ	179.39 (11)
C17—C18—C19—O11	2.7 (3)	O6—C13—O5—Ca1ⁱⁱ	177.84 (13)
C26—C18—C19—C20	2.1 (2)	C8—C13—O5—Ca1ⁱⁱ	−2.1 (2)
C17—C18—C19—C20	−177.06 (16)	O7—C14—O8—Ca1	97.5 (2)
O11—C19—C20—O12	−7.9 (2)	C10—C14—O8—Ca1	−79.0 (2)
C18—C19—C20—O12	171.94 (15)	C21—C20—O12—Ca3	−10.8 (2)
O11—C19—C20—C21	173.47 (15)	C19—C20—O12—Ca3	170.58 (11)
C18—C19—C20—C21	−6.7 (2)	O14—C27—O13—Ca3	−179.65 (12)
O12—C20—C21—N4	6.0 (2)	C22—C27—O13—Ca3	−1.2 (2)
C19—C20—C21—N4	−175.40 (14)	O13—C27—O14—Ca1	−135.4 (3)
O12—C20—C21—C25	−170.03 (15)	C22—C27—O14—Ca1	46.2 (4)
C19—C20—C21—C25	8.6 (2)	O16—C28—O15—Ca2	−14.3 (3)
N4—C22—C23—C24	−2.3 (3)	C24—C28—O15—Ca2	164.88 (12)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y+1, −z+1; (iii) x+1, y, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H2···O8	0.86 (2)	2.01 (2)	2.7232 (19)	139.6 (19)
N3—H4···O16	0.86 (2)	1.83 (2)	2.6163 (19)	151 (2)
O17—H171···O10^iv	0.85 (3)	1.91 (3)	2.7543 (18)	170 (3)
O17—H172···O1	0.86 (3)	2.08 (3)	2.9287 (19)	170 (2)
O18—H181···O28	0.88 (3)	1.82 (3)	2.681 (2)	166 (2)
O18—H182···O1ⁱⁱⁱ	0.84 (3)	1.97 (3)	2.8107 (19)	176 (3)
O19—H191···O20ⁱ	0.81 (3)	2.10 (3)	2.8789 (19)	161 (3)
O19—H192···O5ⁱⁱ	0.85 (3)	1.89 (3)	2.7350 (18)	174 (3)
O20—H201···O11^v	0.82 (3)	2.00 (3)	2.8221 (18)	173 (3)
O20—H202···O2^vi	0.84 (3)	1.94 (3)	2.7620 (18)	169 (3)
O21—H211···O29^iv	0.80 (3)	2.05 (3)	2.845 (2)	173 (3)
O21—H212···O16	0.85 (3)	1.90 (3)	2.7320 (18)	163 (3)
O22—H221···O19^vi	0.76 (3)	2.26 (3)	2.958 (2)	152 (3)
O22—H222···O6^vii	0.87 (3)	1.83 (3)	2.6985 (19)	175 (3)
O23—H231···O3^viii	0.76 (3)	2.10 (3)	2.8398 (19)	164 (3)
O23—H232···O9^iv	0.83 (3)	1.90 (3)	2.7217 (19)	169 (3)
O24—H241···O7^ix	0.81 (3)	2.03 (3)	2.8040 (19)	163 (3)
O24—H242···O29	0.82 (3)	1.93 (3)	2.750 (2)	172 (3)
O25—H251···O13^ix	0.85 (3)	2.02 (3)	2.8578 (18)	168 (3)
O25—H252···O3^viii	0.81 (3)	2.41 (3)	3.0258 (19)	133 (2)
O25—H252···O4^viii	0.81 (3)	2.28 (3)	3.0405 (18)	155 (3)
O26—H261···O27^x	0.86 (3)	2.11 (3)	2.9018 (19)	154 (3)
O26—H262···O13^ix	0.80 (3)	2.06 (3)	2.8506 (19)	170 (3)
O27—H271···O25ⁱⁱⁱ	0.85 (3)	2.08 (3)	2.9022 (19)	164 (3)
O27—H272···O9^v	0.83 (3)	1.99 (3)	2.8125 (18)	171 (2)
O28—H281···O10^v	0.89 (4)	1.88 (4)	2.721 (2)	159 (3)
O28—H282···O26^x	0.83 (4)	2.59 (3)	3.098 (2)	121 (3)
O29—H291···O6^ix	0.84 (3)	1.85 (3)	2.6582 (19)	160 (3)
O29—H292···O11	0.79 (3)	2.27 (3)	3.021 (2)	159 (3)
O29—H292···O12	0.79 (3)	2.40 (3)	2.7789 (19)	110 (2)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y+1, −z+1; (iii) x+1, y, z; (iv) −x+1, −y, −z; (v) −x+2, −y, −z; (vi) −x+1, −y, −z+1; (vii) x, y−1, z; (viii) x, y, z−1; (ix) −x+1, −y+1, −z; (x) −x+2, −y+1, −z.

Selected bond lengths (Å) of the Ca₃PQQ₂.13H₂O complex in comparison with the previously published Eu₂PQQ₂.12H₂O structure top

For symmetry data for Eu₂PQQ₂.12H₂O, please see (Lumpe et al., 2020).

Ca₃PQQ₂.13H₂O		Eu₂PQQ₂.12H₂O
Ca1ⁱ—O4	2.5928 (12)	Eu1—O4	2.584 (2)
Ca1ⁱ—N2	2.5069 (14)	Eu1—N2	2.648 (2)
Ca1ⁱ—O5	2.3784 (12)	Eu1—O5	2.440 (2)
Ca1—O14	2.2514 (12)	Eu1—O1	2.409 (2)
Ca1—O8	2.3137 (12)	Eu1—O_water (5 bonds)	2.389 (2)–2.464 (2)
Ca1—O17	2.3694 (13)
Ca1—O18	2.3145 (14)	Ca3—O12	2.5703 (12)
Ca2ⁱⁱ—O1	2.4812 (12)	Ca3—N4	2.5460 (14)
Ca2ⁱⁱ—O2	2.5279 (12)	Ca3—O13	2.3963 (12)
Ca2—O15	2.3522 (12)	Ca3—O23	2.4362 (14)
Ca2—O19	2.3894 (14)	Ca3—O24	2.3607 (13)
Ca2—O20	2.4382 (13)	Ca3—O25	2.5787 (14)
Ca2—O21	2.3824 (14)	Ca3—O26	2.3962 (14)
Ca2—O22	2.3383 (14)	Ca3—O27	2.4924 (14)

Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x-1, y, z.

Footnotes

¹Dedicated to Professor Wolfgang Kaim on the occasion of his 70th birthday.

Acknowledgements

Open access funding enabled and organized by Projekt DEAL.

Funding information

Funding for this research was provided by: Deutsche Forschungsgemeinschaft (grant No. 392552271 to LJD).

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