Crystal structure of bis­[(oxalato-κ2O1,O2)(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4N)chromium(III)] dichromate octa­hydrate from synchrotron X-ray data

Moon, D.; Choi, J.-H.

doi:10.1107/S2056989017002614

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ISSN: 2056-9890

Volume 73| Part 3| March 2017| Pages 403-406

https://doi.org/10.1107/S2056989017002614

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Crystal structure of bis[(oxalato-κ²O¹,O²)(1,4,8,11-tetraazacyclotetradecane-κ⁴N)chromium(III)] dichromate octahydrate from synchrotron X-ray data

Dohyun Moon ^a and Jong-Ha Choi ^b ^*

^aPohang Accelerator Laboratory, POSTECH, Pohang 37673, Republic of Korea, and ^bDepartment of Chemistry, Andong National University, Andong 36729, Republic of Korea
^*Correspondence e-mail: jhchoi@anu.ac.kr

Edited by J. Simpson, University of Otago, New Zealand (Received 13 February 2017; accepted 14 February 2017; online 17 February 2017)

The asymmetric unit of the title compound, [Cr(C₂O₄)(C₁₀H₂₄N₄)]₂[Cr₂O₇]·8H₂O (C₁₀H₂₄N₄ = 1,4,8,11-tetraazacyclotetradecane, cyclam; C₂O₄ = oxalate, ox) contains one [Cr(ox)(cyclam)]⁺ cation, one half of a dichromate anion that lies about an inversion centre so that the bridging O atom is equally disordered over two positions, and four water molecules. The terminal O atoms of the dichromate anion are also disordered over two positions with a refined occupancy ratio 0.586 (6):0.414 (6). The Cr^III ion is coordinated by the four N atoms of the cyclam ligand and one bidentate oxalato ligand in a cis arrangement, resulting in a distorted octahedral geometry. The Cr—N(cyclam) bond lengths are in the range 2.069 (2)–2.086 (2) Å, while the average Cr—O(ox) bond length is 1.936 Å. The macrocyclic cyclam moiety adopts the cis-V conformation. The dichromate anion has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the cyclam N—H groups and water O—H groups as donors, and the O atoms of oxalate ligand, water molecules and the Cr₂O₇²⁻ anion as acceptors, giving rise to a three-dimensional network.

Keywords: crystal structure; cyclam; chromium(III) complex; bidentate oxalato ligand; cis-V conformation; dichromate anion; hydrogen bonding; synchrotron radiation.

CCDC reference: 1532785

1. Chemical context

Chromium (Cr) is considered a trace element essential for the proper functioning of living organisms and is also a highly toxic material (Yusof & Malek, 2009 ). Cr can exist in all oxidation states from 0 to VI, the most common oxidation states in water being Cr^III and Cr^VI. In an aqueous environment, the toxicity of Cr^VI has been shown to be greater than that of Cr^III (Guzel et al., 2016 ). Transition metal complexes of the cyclam (1,4,8,11-tetraazacyclotetradecane, C₁₀H₂₄N₄) ligand have been the subject of numerous investigations because of their particular conformational stereochemistry (Poon & Pun, 1980 ; Choi, 2009 ; Subhan et al., 2011 ). Recently, it has been found that cyclam derivatives and their metal complexes exhibit anti-HIV activity (Ronconi & Sadler, 2007 ; De Clercq, 2010 ; Ross et al., 2012 ). The conformation of the macrocyclic ligand is a very important factor for co-receptor recognition. Therefore, knowledge of the conformation and hydrogen-bonding interactions in Cr^III–Cr^VI complex systems containing the cyclam ligand has become important in the development of new anti-HIV drugs (De Clercq, 2010). The use of such complexes for the more effective removal of toxic metals is also important (Guzel et al., 2016). As part of a study of the conformation and structure of (cyclam)chromium(III) complexes with auxiliary ligand(s) and various anions, we report here the structural characterization of the new complex salt, [Cr(C₂O₄)(C₁₀H₂₄N₄)]₂[Cr₂O₇]·8H₂O, (I).

2. Structural commentary

An ellipsoid plot of the molecular components in (I) is shown in Fig. 1 along with the atom-numbering scheme. The structure is another example of a [Cr(ox)(cyclam)]⁺ cation (Choi et al., 2004b ; Moon & Choi, 2016b ), but with a different counter-anion. The asymmetric unit contains one [Cr(ox)(cyclam)]⁺ cation, one half of a Cr₂O₇²⁻ anion (completed by inversion symmetry with the bridging O atom disordered about the inversion centre) and four non-coordinating water molecules. The three terminal O atoms of the dichromate anion are also disordered over two positions with occupancy ratio of the atom pairs O2B1/O2B2, O3B1/O3B2 and O4B1/O4B2 converging at 0.586 (6):0.414 (6). The conformation of the cyclam ligand can be described as cis-V (anti–anti) (Subhan et al., 2011). In the complex cation, the Cr^III ion is coordinated by the four nitrogen atoms of the cyclam ligand in a folded conformation. Two oxygen atoms of the oxalato ligand complete the distorted octahedral coordination sphere. The Cr—N bond lengths from the donor atoms of cyclam ligand lie in the range 2.069 (2) to 2.086 (2) Å, in good agreement with those determined in cis-[Cr(N₃)₂(cyclam)]ClO₄ [2.069 (3)–2.103 (3) Å] (Meyer et al., 1998 ), cis-[Cr(ONO)₂(cyclam)]NO₂ [2.0874 (16)–2.0916 (15) Å] (Choi et al., 2004a ), [Cr(acac)(cyclam)](ClO₄)₂·0.5H₂O [2.070 (5)–2.089 (5) Å] (acac = acetylacetonate; Subhan et al., 2011), cis-[Cr(NCS)₂(cyclam)]NCS [2.0851 (14)–2.0897 (14) Å] (Moon et al., 2013 ) and [CrCl₂(cyclam)][Cr(ox)(cyclam)](ClO₄)₂ [2.075 (5)–2.096 (5) Å] (Moon & Choi, 2016b). However, the Cr—N bond lengths of the cyclam ligand with a cis geometry are slightly longer than those found in trans-[Cr(NCS)₂(cyclam)]ClO₄ [2.046 (2)–2.060 (2) Å] (Friesen et al., 1997 ), trans-[Cr(ONO)₂)(cyclam)]BF₄ [2.064 (4)–2.073 (4) Å] (De Leo et al., 2000 ), trans-[Cr(NH₃)₂(cyclam)][ZnCl₄]Cl·H₂O [2.0501 (15)–2.0615 (15) Å] (Moon & Choi, 2016a ) and trans-[Cr(nic-O)₂(cyclam)]ClO₄ [2.058 (4)–2.064 (4) Å] (nic-O = O-coordinated nicotinate; Choi, 2009).

Figure 1
A perspective view of the asymmetric unit of the title of compound, (I)

, with the dichromate anion, which lies about an inversion centre, drawn in full. Displacement ellipsoids are drawn at the 30% probability level and primed atoms are related by the symmetry operation (2 − x, −y, 1 − z). For clarity, only the major disorder components are shown for the disordered dichromate anion.

The Cr1A—O1A distance [1.9665 (16) Å] in the oxalate ligand is very slightly longer than the Cr1A—O3A [1.9600 (16) Å] bond length. This elongation may be attributed to the weak hydrogen bond formed by O1A (x, −y + $[{1\over 2}]$ , z − $[{1\over 2}]$ ) with the O3S—H2O3 atoms of a water molecule. The mean Cr—O bond length is comparable to the mean values of 1.959, 1.956 and 1.969 Å observed in [Cr(ox)(cyclam)]ClO₄ (Choi et al., 2004b), [CrCl₂(cyclam)][Cr(ox)(cyclam)](ClO₄)₂ (Moon & Choi, 2016b) and K₃[Cr(ox)₃]·3H₂O (Taylor, 1978 ), respectively. The five- and six-membered chelate rings of the cyclam ligand adopt gauche and stable chair conformations, respectively. As expected for a bidentate ox ligand, the O1A—Cr1A—O3A bite angle 82.34 (7)° is considerably less than 90°, while the folding angle of the cyclam in the [Cr(ox)(cyclam)]⁺ cation is 98.97 (8)°. The significant distortion of the octahedron and the larger folding angle in the [Cr(ox)(cyclam)]⁺ cation seem to arise from the small bite angle of the bidentate oxalato ligand.

It is of interest to compare the conformation of the Cr₂O₇²⁻ anion with that found in other ionic crystals. In (I), the Cr₂O₇²⁻ anion exhibits a staggered conformation whereas a nearly eclipsed conformation is observed for (C₉H₁₄N)₂[Cr₂O₇] and (C₁₀H₂₂N₂)[Cr₂O₇], when viewed along the backbone of the dichromate anion (Trabelsi et al., 2015 ; Chebbi et al., 2016 ). This structural conformation of dichromate seems to depend on the size of the associated counter-cation (Moon et al., 2015 , 2017 ). The O1B—Cr2B—O bond angles range from 107.1 (3) to 117.0 (3)°; while the terminal Cr2B—O bond lengths vary from 1.572 (12) to 1.673 (5) Å, with a mean terminal Cr2B—O bond length of 1.627 Å. The bridging Cr2B—O1B bond is 1.684 (4) Å long, with the Cr2B—O1B—Cr2B(−x + 2, −y, −z + 1) bond angle of 136.0 (3)°. These values are similar to those reported for the anions in the structures of [Cr(urea)₆][Cr₂O₇]Br·H₂O (Moon et al., 2015) and [Cr(NCS)₂(cyclam)]₂[Cr₂O₇]·H₂O (Moon et al., 2017). A further distortion of the anion undoubtedly results from its involvement in hydrogen-bonding interactions with the solvent water molecules (see Supramolecular features).

3. Supramolecular features

In the asymmetric unit, O—H⋯O and N—H⋯O hydrogen bonds link the water molecules to the Cr₂O₇²⁻ anion, [Cr(ox)(cyclam)]⁺ cation and other water molecules, while N—H⋯O hydrogen bonds involving the cyclam N–H groups and the O atoms of oxalate interconnect two [Cr(ox)(cyclam)]⁺ cations (Table 1, Figs. 1 and 2). An extensive array of these contacts generate a three-dimensional network of molecules (Fig. 2), and these hydrogen-bonding interactions help to stabilize the crystal structure.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1A—H1A⋯O4Aⁱ	0.98	1.99	2.804 (3)	139
N2A—H2A⋯O1S	0.98	2.00	2.894 (3)	150
N3A—H3A⋯O2Aⁱ	0.98	1.89	2.842 (3)	163
N4A—H4A⋯O2B1ⁱⁱ	0.98	2.25	3.100 (16)	144
N4A—H4A⋯O4B1ⁱⁱ	0.98	2.37	3.108 (6)	132
N4A—H4A⋯O4B2ⁱⁱ	0.98	2.15	3.05 (2)	151
O1S—H1O1⋯O4B1	0.85 (1)	2.33 (5)	2.876 (6)	123 (5)
O1S—H1O1⋯O3B2	0.85 (1)	2.20 (4)	2.903 (10)	141 (5)
O2S—H2O2⋯O3S	0.85 (1)	1.91 (2)	2.729 (6)	164 (6)
O3S—H1O3⋯O3B1	0.85 (1)	1.93 (3)	2.725 (6)	156 (7)
O3S—H1O3⋯O3B2	0.85 (1)	2.28 (2)	3.113 (10)	167 (6)
O3S—H2O3⋯O1Aⁱⁱⁱ	0.85 (1)	2.52 (3)	3.301 (4)	154 (6)
O3S—H2O3⋯O2Aⁱⁱⁱ	0.85 (1)	2.21 (5)	2.911 (5)	140 (6)
O4S—H1O4⋯O4A	0.84 (1)	2.11 (4)	2.834 (4)	144 (6)
O4S—H2O4⋯O2S	0.85 (1)	1.89 (2)	2.723 (5)	166 (6)
Symmetry codes: (i) x-1, y, z; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (iii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Figure 2
The crystal packing in compound (I)

, viewed perpendicular to the bc plane. Dashed lines represent N—H⋯O (pink) and O—H⋯O (cyan) hydrogen-bonding interactions, respectively. C-bound H atoms have been omitted.

4. Database survey

A search of the Cambridge Structural Database (Version 5.37, Feb 2016 with two updates; Groom et al., 2016 ) gave just one hit for a [Cr(C₂O₄)(C₁₀H₂₄N₄)]⁺ unit, namely the complex [Cr(ox)(cyclam)]ClO₄ (Choi et al., 2004b). However, the structure of [CrCl₂(cyclam)][Cr(ox)(cyclam)](ClO₄)₂ (Moon & Choi, 2016b) has also been reported recently. Until now, no structure of the [Cr(ox)(cyclam)]⁺ cation with a dichromate counter-anion has been deposited.

5. Synthesis and crystallization

The free ligand cyclam (98%) was purchased from Sigma–Aldrich and used without further purification. All chemicals were reagent grade materials, and were used as received. The starting material, [Cr(ox)(cyclam)]ClO₄ was prepared according to the literature method (House & McKee, 1984 ). The perchlorate salt of the complex (0.03 g) was dissolved in 10 mL of distilled water at 347 K. The solution was filtered and the filtrate was added to 5 mL of water containing solid K₂Cr₂O₇ (0.02 g). Orange block-like crystals of (I) suitable for X-ray structural analysis were obtained after one week of slow evaporation at room temperature.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.97 Å and N—H = 0.98 Å, and with U_iso(H) values of 1.2U_eq of the parent atoms. The hydrogen atoms of the solvent water molecules were assigned based on a difference-Fourier map, and the O—H distance and the H—O—H angle were restrained using DFIX and DANG constraints. The terminal O atoms of the dichromate anion are positionally disordered over two sets of sites. The occupancies of the respective pairs, O2B1/O2B2, O3B1/O3B2 and O4B1/O4B2, were refined freely and, for the O2B2 and O3B2 atoms, ISOR restraints were applied. The occupancy ratio refined to 0.586 (6):0.414 (6). The bridging O1B atom of the dichromate anion is also disordered, in this case about the inversion centre. Consequently the components were refined at half-occupancy. The bridging atoms O1B/O1B (−x + 2, −y, −z + 1) sites were refined using EXYZ/EADP restraints.

Table 2
Experimental details

Crystal data
Chemical formula	[Cr(C₂O₄)(C₁₀H₂₄N₄)]₂[Cr₂O₇]·8H₂O
M_r	1040.83
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	7.8270 (16), 15.407 (3), 18.086 (4)
β (°)	100.86 (3)
V (Å³)	2141.9 (8)
Z	2
Radiation type	Synchrotron, λ = 0.610 Å
μ (mm⁻¹)	0.71
Crystal size (mm)	0.15 × 0.09 × 0.08

Data collection
Diffractometer	ADSC Q210 CCD area detector
Absorption correction	Empirical (using intensity measurements) (HKL3000sm SCALEPACK; Otwinowski & Minor, 1997 )
T_min, T_max	0.889, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	21270, 5775, 4844
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.693

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.145, 1.04
No. of reflections	5775
No. of parameters	324
No. of restraints	24
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	1.62, −0.69
Computer programs: PAL BL2D-SMDC (Shin et al., 2016 ), HKL3000sm (Otwinowski & Minor, 1997), SHELXT2014 (Sheldrick, 2015a ), SHELXL2016 (Sheldrick, 2015b ), DIAMOND 4 (Putz & Brandenburg, 2014 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1532785

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989017002614/sj5521sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017002614/sj5521Isup2.hkl

checkCIF report

Computing details top

Data collection: PAL BL2D-SMDC (Shin et al., 2016); cell refinement: HKL3000sm (Otwinowski & Minor, 1997); data reduction: HKL3000sm (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015b); molecular graphics: DIAMOND 4 (Putz & Brandenburg, 2014); software used to prepare material for publication: publCIF (Westrip, 2010).

Bis[(oxalato-κ²O¹,O²)(1,4,8,11-tetraazacyclotetradecane-κ⁴N)chromium(III)] dichromate octahydrate top

Crystal data top

[Cr(C₂O₄)(C₁₀H₂₄N₄)]₂[Cr₂O₇]·8H₂O	F(000) = 1088
M_r = 1040.83	D_x = 1.614 Mg m⁻³
Monoclinic, P2₁/c	Synchrotron radiation, λ = 0.610 Å
a = 7.8270 (16) Å	Cell parameters from 63673 reflections
b = 15.407 (3) Å	θ = 0.4–33.7°
c = 18.086 (4) Å	µ = 0.71 mm⁻¹
β = 100.86 (3)°	T = 298 K
V = 2141.9 (8) Å³	Block, orange
Z = 2	0.15 × 0.09 × 0.08 mm

Data collection top

ADSC Q210 CCD area detector diffractometer	4844 reflections with I > 2σ(I)
Radiation source: PLSII 2D bending magnet	R_int = 0.027
ω scan	θ_max = 25.0°, θ_min = 2.3°
Absorption correction: empirical (using intensity measurements) (HKL3000sm SCALEPACK; Otwinowski & Minor, 1997)	h = −10→10
T_min = 0.889, T_max = 1.000	k = −20→20
21270 measured reflections	l = −25→25
5775 independent reflections

Refinement top

Refinement on F²	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.048	w = 1/[σ²(F_o²) + (0.0902P)² + 1.1358P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.145	(Δ/σ)_max = 0.002
S = 1.04	Δρ_max = 1.62 e Å⁻³
5775 reflections	Δρ_min = −0.69 e Å⁻³
324 parameters	Extinction correction: SHELXL2016 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
24 restraints	Extinction coefficient: 0.037 (3)

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.

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Cr1A	0.38205 (4)	0.34112 (2)	0.73752 (2)	0.02641 (13)
O1A	0.59297 (19)	0.27010 (12)	0.76591 (10)	0.0396 (4)
O2A	0.8739 (2)	0.26797 (16)	0.76043 (14)	0.0626 (6)
O3A	0.54391 (19)	0.41929 (11)	0.69995 (10)	0.0396 (4)
O4A	0.8222 (2)	0.43225 (16)	0.69140 (14)	0.0598 (6)
N1A	0.1816 (2)	0.42579 (13)	0.69489 (12)	0.0378 (4)
H1A	0.075547	0.405210	0.710638	0.045*
N2A	0.3113 (2)	0.27935 (15)	0.63360 (12)	0.0409 (4)
H2A	0.403674	0.293806	0.605848	0.049*
N3A	0.2422 (2)	0.25158 (13)	0.78721 (12)	0.0390 (4)
H3A	0.119637	0.269026	0.775430	0.047*
N4A	0.4158 (3)	0.40170 (14)	0.84214 (11)	0.0406 (4)
H4A	0.535961	0.389115	0.866550	0.049*
C1A	0.1568 (4)	0.4172 (2)	0.61046 (18)	0.0582 (8)
H1AA	0.049076	0.445014	0.586857	0.070*
H1AB	0.252088	0.445169	0.592350	0.070*
C2A	0.1514 (4)	0.3226 (2)	0.59104 (18)	0.0612 (8)
H2AA	0.048592	0.296162	0.604142	0.073*
H2AB	0.145782	0.315414	0.537358	0.073*
C3A	0.3008 (4)	0.1838 (2)	0.6321 (2)	0.0609 (8)
H3AA	0.417078	0.160207	0.647097	0.073*
H3AB	0.256590	0.165122	0.580818	0.073*
C4A	0.1857 (4)	0.1466 (2)	0.6829 (2)	0.0638 (9)
H4AA	0.071236	0.172674	0.669584	0.077*
H4AB	0.172624	0.084736	0.673435	0.077*
C5A	0.2513 (4)	0.16009 (18)	0.7649 (2)	0.0586 (8)
H5AA	0.183071	0.125105	0.793222	0.070*
H5AB	0.371013	0.140530	0.777515	0.070*
C6A	0.3031 (4)	0.2623 (2)	0.87113 (18)	0.0597 (8)
H6AA	0.224823	0.232351	0.898189	0.072*
H6AB	0.418710	0.238033	0.886411	0.072*
C7A	0.3053 (5)	0.3571 (3)	0.88827 (18)	0.0640 (8)
H7AA	0.187953	0.380198	0.876854	0.077*
H7AB	0.351179	0.366653	0.941312	0.077*
C8A	0.3993 (4)	0.4980 (2)	0.8437 (2)	0.0605 (8)
H8AA	0.493986	0.523712	0.823521	0.073*
H8AB	0.410781	0.516864	0.895598	0.073*
C9A	0.2285 (4)	0.5313 (2)	0.7993 (2)	0.0657 (9)
H9AA	0.133959	0.502373	0.817229	0.079*
H9AB	0.219591	0.592861	0.809118	0.079*
C10A	0.2063 (4)	0.51784 (19)	0.7163 (2)	0.0595 (8)
H10A	0.106358	0.550800	0.691276	0.071*
H10B	0.308132	0.539863	0.699087	0.071*
C11A	0.7305 (3)	0.30305 (18)	0.74841 (14)	0.0415 (5)
C12A	0.7022 (3)	0.39281 (18)	0.70995 (14)	0.0412 (5)
Cr2B	0.86158 (6)	0.07641 (3)	0.46646 (2)	0.04561 (15)
O1B	0.9327 (6)	−0.0145 (4)	0.5141 (3)	0.0780 (16)	0.5
O2B1	0.814 (2)	0.0661 (9)	0.3785 (7)	0.068 (3)	0.586 (6)
O3B1	0.9854 (7)	0.1624 (3)	0.4827 (3)	0.0797 (17)	0.586 (6)
O4B1	0.6779 (6)	0.1061 (4)	0.4942 (3)	0.0811 (16)	0.586 (6)
O2B2	0.7152 (9)	0.0097 (6)	0.4864 (4)	0.093 (3)	0.414 (6)
O3B2	0.8779 (13)	0.1556 (6)	0.5165 (5)	0.097 (3)	0.414 (6)
O4B2	0.812 (3)	0.0895 (14)	0.3789 (11)	0.075 (5)	0.414 (6)
O1S	0.6259 (5)	0.2636 (2)	0.57243 (19)	0.0909 (10)
H1O1	0.698 (7)	0.222 (3)	0.577 (3)	0.136*
H2O1	0.596 (8)	0.269 (4)	0.5252 (8)	0.136*
O2S	0.6340 (5)	0.3977 (2)	0.4684 (2)	0.0935 (9)
H1O2	0.576 (7)	0.382 (4)	0.501 (3)	0.140*
H2O2	0.698 (7)	0.362 (3)	0.450 (3)	0.140*
O3S	0.8777 (6)	0.3113 (2)	0.4068 (2)	0.1014 (11)
H1O3	0.880 (9)	0.264 (2)	0.431 (3)	0.152*
H2O3	0.827 (8)	0.300 (4)	0.3622 (14)	0.152*
O4S	0.7101 (5)	0.5364 (2)	0.56219 (18)	0.0920 (9)
H1O4	0.708 (9)	0.519 (3)	0.6063 (12)	0.138*
H2O4	0.675 (8)	0.499 (3)	0.528 (2)	0.138*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cr1A	0.01035 (16)	0.0353 (2)	0.03406 (19)	0.00068 (10)	0.00548 (11)	−0.00334 (12)
O1A	0.0188 (7)	0.0472 (10)	0.0521 (9)	0.0076 (6)	0.0050 (6)	−0.0005 (7)
O2A	0.0197 (8)	0.0833 (16)	0.0835 (15)	0.0165 (8)	0.0066 (8)	−0.0129 (12)
O3A	0.0177 (7)	0.0490 (10)	0.0546 (10)	−0.0027 (6)	0.0133 (6)	0.0023 (7)
O4A	0.0229 (8)	0.0871 (16)	0.0737 (14)	−0.0124 (9)	0.0203 (8)	−0.0010 (11)
N1A	0.0173 (8)	0.0424 (11)	0.0544 (11)	0.0062 (7)	0.0089 (7)	0.0063 (8)
N2A	0.0258 (9)	0.0561 (12)	0.0409 (10)	−0.0004 (8)	0.0066 (7)	−0.0124 (9)
N3A	0.0216 (8)	0.0435 (11)	0.0537 (11)	−0.0007 (7)	0.0115 (8)	0.0059 (8)
N4A	0.0273 (9)	0.0533 (12)	0.0408 (10)	−0.0009 (8)	0.0058 (7)	−0.0127 (8)
C1A	0.0373 (13)	0.080 (2)	0.0565 (16)	0.0114 (13)	0.0069 (11)	0.0225 (15)
C2A	0.0434 (15)	0.087 (2)	0.0473 (15)	0.0015 (15)	−0.0069 (12)	−0.0098 (14)
C3A	0.0495 (16)	0.0600 (18)	0.073 (2)	−0.0032 (13)	0.0114 (14)	−0.0286 (15)
C4A	0.0488 (17)	0.0501 (17)	0.093 (2)	−0.0108 (12)	0.0130 (16)	−0.0183 (15)
C5A	0.0442 (15)	0.0407 (15)	0.092 (2)	−0.0025 (10)	0.0169 (15)	0.0052 (13)
C6A	0.0497 (16)	0.077 (2)	0.0546 (16)	0.0013 (14)	0.0162 (13)	0.0168 (14)
C7A	0.067 (2)	0.086 (2)	0.0446 (15)	−0.0042 (17)	0.0243 (14)	−0.0113 (14)
C8A	0.0517 (17)	0.0561 (18)	0.074 (2)	−0.0037 (13)	0.0125 (14)	−0.0275 (15)
C9A	0.0498 (17)	0.0528 (18)	0.097 (3)	0.0099 (13)	0.0195 (16)	−0.0179 (16)
C10A	0.0376 (14)	0.0447 (15)	0.098 (2)	0.0084 (11)	0.0189 (14)	0.0074 (14)
C11A	0.0160 (9)	0.0608 (15)	0.0470 (12)	0.0055 (9)	0.0041 (8)	−0.0140 (10)
C12A	0.0177 (9)	0.0612 (15)	0.0472 (12)	−0.0071 (9)	0.0120 (8)	−0.0119 (10)
Cr2B	0.0406 (2)	0.0553 (3)	0.0379 (2)	0.00143 (17)	−0.00027 (16)	0.00325 (16)
O1B	0.058 (3)	0.083 (3)	0.094 (4)	0.032 (3)	0.016 (3)	0.051 (3)
O2B1	0.074 (5)	0.082 (6)	0.042 (4)	0.010 (4)	−0.002 (3)	−0.009 (4)
O3B1	0.076 (3)	0.065 (3)	0.086 (3)	−0.025 (2)	−0.016 (3)	−0.006 (2)
O4B1	0.066 (3)	0.095 (4)	0.087 (3)	0.011 (2)	0.027 (2)	−0.005 (3)
O2B2	0.065 (4)	0.126 (6)	0.094 (5)	−0.007 (4)	0.027 (3)	0.045 (4)
O3B2	0.096 (3)	0.095 (3)	0.097 (3)	0.0059 (19)	0.0135 (19)	−0.0124 (18)
O4B2	0.050 (5)	0.113 (13)	0.060 (7)	0.023 (7)	0.009 (5)	0.047 (7)
O1S	0.097 (2)	0.102 (2)	0.089 (2)	0.0078 (17)	0.0558 (19)	−0.0074 (17)
O2S	0.110 (3)	0.082 (2)	0.089 (2)	0.0060 (18)	0.0202 (18)	−0.0030 (16)
O3S	0.131 (3)	0.084 (2)	0.082 (2)	0.013 (2)	0.003 (2)	−0.0045 (16)
O4S	0.111 (3)	0.091 (2)	0.0739 (18)	0.0025 (19)	0.0187 (19)	−0.0037 (15)

Geometric parameters (Å, º) top

Cr1A—O3A	1.9600 (16)	C5A—H5AB	0.9700
Cr1A—O1A	1.9665 (16)	C6A—C7A	1.493 (5)
Cr1A—N3A	2.069 (2)	C6A—H6AA	0.9700
Cr1A—N1A	2.0739 (19)	C6A—H6AB	0.9700
Cr1A—N4A	2.081 (2)	C7A—H7AA	0.9700
Cr1A—N2A	2.086 (2)	C7A—H7AB	0.9700
O1A—C11A	1.283 (3)	C8A—C9A	1.513 (5)
O2A—C11A	1.228 (3)	C8A—H8AA	0.9700
O3A—C12A	1.284 (3)	C8A—H8AB	0.9700
O4A—C12A	1.218 (3)	C9A—C10A	1.493 (5)
N1A—C10A	1.473 (4)	C9A—H9AA	0.9700
N1A—C1A	1.508 (4)	C9A—H9AB	0.9700
N1A—H1A	0.9800	C10A—H10A	0.9700
N2A—C3A	1.475 (4)	C10A—H10B	0.9700
N2A—C2A	1.497 (4)	C11A—C12A	1.545 (4)
N2A—H2A	0.9800	Cr2B—O3B2	1.511 (8)
N3A—C5A	1.472 (4)	Cr2B—O4B2	1.571 (19)
N3A—C6A	1.512 (4)	Cr2B—O2B1	1.572 (12)
N3A—H3A	0.9800	Cr2B—O2B2	1.630 (7)
N4A—C7A	1.479 (4)	Cr2B—O3B1	1.635 (4)
N4A—C8A	1.491 (4)	Cr2B—O4B1	1.673 (5)
N4A—H4A	0.9800	Cr2B—O1B	1.684 (4)
C1A—C2A	1.498 (5)	Cr2B—O1Bⁱ	1.847 (4)
C1A—H1AA	0.9700	O1B—O1Bⁱ	1.332 (10)
C1A—H1AB	0.9700	O1B—O2B2	1.723 (9)
C2A—H2AA	0.9700	O1S—H1O1	0.845 (10)
C2A—H2AB	0.9700	O1S—H2O1	0.847 (10)
C3A—C4A	1.516 (5)	O2S—H1O2	0.841 (10)
C3A—H3AA	0.9700	O2S—H2O2	0.845 (10)
C3A—H3AB	0.9700	O3S—H1O3	0.845 (10)
C4A—C5A	1.489 (5)	O3S—H2O3	0.848 (10)
C4A—H4AA	0.9700	O4S—H1O4	0.843 (10)
C4A—H4AB	0.9700	O4S—H2O4	0.851 (10)
C5A—H5AA	0.9700

O3A—Cr1A—O1A	82.34 (7)	N3A—C5A—H5AB	109.1
O3A—Cr1A—N3A	171.83 (8)	C4A—C5A—H5AB	109.1
O1A—Cr1A—N3A	90.14 (8)	H5AA—C5A—H5AB	107.8
O3A—Cr1A—N1A	88.72 (7)	C7A—C6A—N3A	107.7 (2)
O1A—Cr1A—N1A	170.42 (8)	C7A—C6A—H6AA	110.2
N3A—Cr1A—N1A	98.97 (8)	N3A—C6A—H6AA	110.2
O3A—Cr1A—N4A	93.44 (8)	C7A—C6A—H6AB	110.2
O1A—Cr1A—N4A	93.19 (8)	N3A—C6A—H6AB	110.2
N3A—Cr1A—N4A	83.74 (9)	H6AA—C6A—H6AB	108.5
N1A—Cr1A—N4A	90.77 (9)	N4A—C7A—C6A	108.8 (2)
O3A—Cr1A—N2A	92.69 (8)	N4A—C7A—H7AA	109.9
O1A—Cr1A—N2A	92.78 (8)	C6A—C7A—H7AA	109.9
N3A—Cr1A—N2A	90.86 (9)	N4A—C7A—H7AB	109.9
N1A—Cr1A—N2A	84.17 (9)	C6A—C7A—H7AB	109.9
N4A—Cr1A—N2A	171.96 (8)	H7AA—C7A—H7AB	108.3
C11A—O1A—Cr1A	114.69 (16)	N4A—C8A—C9A	113.4 (2)
C12A—O3A—Cr1A	115.17 (17)	N4A—C8A—H8AA	108.9
C10A—N1A—C1A	109.6 (2)	C9A—C8A—H8AA	108.9
C10A—N1A—Cr1A	117.10 (17)	N4A—C8A—H8AB	108.9
C1A—N1A—Cr1A	105.39 (15)	C9A—C8A—H8AB	108.9
C10A—N1A—H1A	108.1	H8AA—C8A—H8AB	107.7
C1A—N1A—H1A	108.1	C10A—C9A—C8A	114.2 (3)
Cr1A—N1A—H1A	108.1	C10A—C9A—H9AA	108.7
C3A—N2A—C2A	113.4 (2)	C8A—C9A—H9AA	108.7
C3A—N2A—Cr1A	118.47 (19)	C10A—C9A—H9AB	108.7
C2A—N2A—Cr1A	108.32 (17)	C8A—C9A—H9AB	108.7
C3A—N2A—H2A	105.2	H9AA—C9A—H9AB	107.6
C2A—N2A—H2A	105.2	N1A—C10A—C9A	112.5 (3)
Cr1A—N2A—H2A	105.2	N1A—C10A—H10A	109.1
C5A—N3A—C6A	111.0 (2)	C9A—C10A—H10A	109.1
C5A—N3A—Cr1A	117.56 (18)	N1A—C10A—H10B	109.1
C6A—N3A—Cr1A	105.70 (17)	C9A—C10A—H10B	109.1
C5A—N3A—H3A	107.4	H10A—C10A—H10B	107.8
C6A—N3A—H3A	107.4	O2A—C11A—O1A	124.3 (3)
Cr1A—N3A—H3A	107.4	O2A—C11A—C12A	121.5 (2)
C7A—N4A—C8A	112.9 (2)	O1A—C11A—C12A	114.15 (18)
C7A—N4A—Cr1A	108.49 (17)	O4A—C12A—O3A	125.2 (3)
C8A—N4A—Cr1A	117.86 (19)	O4A—C12A—C11A	121.2 (2)
C7A—N4A—H4A	105.5	O3A—C12A—C11A	113.63 (19)
C8A—N4A—H4A	105.5	O3B2—Cr2B—O4B2	118.5 (8)
Cr1A—N4A—H4A	105.5	O3B2—Cr2B—O2B2	111.1 (5)
C2A—C1A—N1A	108.4 (2)	O4B2—Cr2B—O2B2	104.7 (8)
C2A—C1A—H1AA	110.0	O2B1—Cr2B—O3B1	106.5 (6)
N1A—C1A—H1AA	110.0	O2B1—Cr2B—O4B1	106.1 (6)
C2A—C1A—H1AB	110.0	O3B1—Cr2B—O4B1	103.8 (3)
N1A—C1A—H1AB	110.0	O3B2—Cr2B—O1B	112.5 (4)
H1AA—C1A—H1AB	108.4	O4B2—Cr2B—O1B	128.2 (8)
N2A—C2A—C1A	109.2 (2)	O2B1—Cr2B—O1B	115.3 (6)
N2A—C2A—H2AA	109.8	O2B2—Cr2B—O1B	62.6 (3)
C1A—C2A—H2AA	109.8	O3B1—Cr2B—O1B	117.0 (3)
N2A—C2A—H2AB	109.8	O4B1—Cr2B—O1B	107.1 (3)
C1A—C2A—H2AB	109.8	O3B2—Cr2B—O1Bⁱ	109.3 (4)
H2AA—C2A—H2AB	108.3	O4B2—Cr2B—O1Bⁱ	107.5 (8)
N2A—C3A—C4A	113.8 (2)	O2B1—Cr2B—O1Bⁱ	100.0 (6)
N2A—C3A—H3AA	108.8	O2B2—Cr2B—O1Bⁱ	104.8 (3)
C4A—C3A—H3AA	108.8	O3B1—Cr2B—O1Bⁱ	85.3 (3)
N2A—C3A—H3AB	108.8	O4B1—Cr2B—O1Bⁱ	148.4 (2)
C4A—C3A—H3AB	108.8	O1B—Cr2B—O1Bⁱ	44.0 (3)
H3AA—C3A—H3AB	107.7	O1Bⁱ—O1B—Cr2B	74.5 (3)
C5A—C4A—C3A	114.7 (3)	O1Bⁱ—O1B—O2B2	128.7 (5)
C5A—C4A—H4AA	108.6	Cr2B—O1B—O2B2	57.1 (3)
C3A—C4A—H4AA	108.6	O1Bⁱ—O1B—Cr2Bⁱ	61.5 (3)
C5A—C4A—H4AB	108.6	Cr2B—O1B—Cr2Bⁱ	136.0 (3)
C3A—C4A—H4AB	108.6	Cr2B—O2B2—O1B	60.2 (3)
H4AA—C4A—H4AB	107.6	H1O1—O1S—H2O1	104 (2)
N3A—C5A—C4A	112.4 (3)	H1O2—O2S—H2O2	122 (3)
N3A—C5A—H5AA	109.1	H1O3—O3S—H2O3	105 (2)
C4A—C5A—H5AA	109.1	H1O4—O4S—H2O4	114 (3)

C10A—N1A—C1A—C2A	174.0 (2)	O2A—C11A—C12A—O4A	−1.2 (4)
Cr1A—N1A—C1A—C2A	47.1 (2)	O1A—C11A—C12A—O4A	178.8 (2)
C3A—N2A—C2A—C1A	166.9 (3)	O2A—C11A—C12A—O3A	178.4 (2)
Cr1A—N2A—C2A—C1A	33.3 (3)	O1A—C11A—C12A—O3A	−1.6 (3)
N1A—C1A—C2A—N2A	−54.5 (3)	O3B2—Cr2B—O1B—O1Bⁱ	−95.0 (7)
C2A—N2A—C3A—C4A	−75.2 (3)	O4B2—Cr2B—O1B—O1Bⁱ	74.6 (12)
Cr1A—N2A—C3A—C4A	53.4 (3)	O2B1—Cr2B—O1B—O1Bⁱ	77.7 (9)
N2A—C3A—C4A—C5A	−66.3 (4)	O2B2—Cr2B—O1B—O1Bⁱ	162.1 (8)
C6A—N3A—C5A—C4A	177.8 (2)	O3B1—Cr2B—O1B—O1Bⁱ	−48.7 (7)
Cr1A—N3A—C5A—C4A	−60.4 (3)	O4B1—Cr2B—O1B—O1Bⁱ	−164.6 (5)
C3A—C4A—C5A—N3A	69.8 (4)	O3B2—Cr2B—O1B—O2B2	103.0 (6)
C5A—N3A—C6A—C7A	175.0 (2)	O4B2—Cr2B—O1B—O2B2	−87.4 (11)
Cr1A—N3A—C6A—C7A	46.5 (3)	O1Bⁱ—Cr2B—O1B—O2B2	−162.1 (8)
C8A—N4A—C7A—C6A	168.8 (3)	O3B2—Cr2B—O1B—Cr2Bⁱ	−95.0 (7)
Cr1A—N4A—C7A—C6A	36.2 (3)	O4B2—Cr2B—O1B—Cr2Bⁱ	74.6 (12)
N3A—C6A—C7A—N4A	−55.8 (3)	O2B1—Cr2B—O1B—Cr2Bⁱ	77.7 (9)
C7A—N4A—C8A—C9A	−72.7 (4)	O2B2—Cr2B—O1B—Cr2Bⁱ	162.1 (8)
Cr1A—N4A—C8A—C9A	55.1 (3)	O3B1—Cr2B—O1B—Cr2Bⁱ	−48.7 (7)
N4A—C8A—C9A—C10A	−67.0 (4)	O4B1—Cr2B—O1B—Cr2Bⁱ	−164.6 (5)
C1A—N1A—C10A—C9A	179.0 (2)	O1Bⁱ—Cr2B—O1B—Cr2Bⁱ	0.005 (1)
Cr1A—N1A—C10A—C9A	−61.1 (3)	O3B2—Cr2B—O2B2—O1B	−105.2 (5)
C8A—C9A—C10A—N1A	70.3 (4)	O4B2—Cr2B—O2B2—O1B	125.8 (8)
Cr1A—O1A—C11A—O2A	−178.9 (2)	O1Bⁱ—Cr2B—O2B2—O1B	12.8 (5)
Cr1A—O1A—C11A—C12A	1.1 (3)	O1Bⁱ—O1B—O2B2—Cr2B	−22.3 (10)
Cr1A—O3A—C12A—O4A	−179.2 (2)	Cr2Bⁱ—O1B—O2B2—Cr2B	−138.9 (13)
Cr1A—O3A—C12A—C11A	1.2 (3)

Symmetry code: (i) −x+2, −y, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1A···O4Aⁱⁱ	0.98	1.99	2.804 (3)	139
N2A—H2A···O1S	0.98	2.00	2.894 (3)	150
N3A—H3A···O2Aⁱⁱ	0.98	1.89	2.842 (3)	163
N4A—H4A···O2B1ⁱⁱⁱ	0.98	2.25	3.100 (16)	144
N4A—H4A···O4B1ⁱⁱⁱ	0.98	2.37	3.108 (6)	132
N4A—H4A···O4B2ⁱⁱⁱ	0.98	2.15	3.05 (2)	151
O1S—H1O1···O4B1	0.85 (1)	2.33 (5)	2.876 (6)	123 (5)
O1S—H1O1···O3B2	0.85 (1)	2.20 (4)	2.903 (10)	141 (5)
O2S—H2O2···O3S	0.85 (1)	1.91 (2)	2.729 (6)	164 (6)
O3S—H1O3···O3B1	0.85 (1)	1.93 (3)	2.725 (6)	156 (7)
O3S—H1O3···O3B2	0.85 (1)	2.28 (2)	3.113 (10)	167 (6)
O3S—H2O3···O1A^iv	0.85 (1)	2.52 (3)	3.301 (4)	154 (6)
O3S—H2O3···O2A^iv	0.85 (1)	2.21 (5)	2.911 (5)	140 (6)
O4S—H1O4···O4A	0.84 (1)	2.11 (4)	2.834 (4)	144 (6)
O4S—H2O4···O2S	0.85 (1)	1.89 (2)	2.723 (5)	166 (6)

Symmetry codes: (ii) x−1, y, z; (iii) x, −y+1/2, z+1/2; (iv) x, −y+1/2, z−1/2.

Acknowledgements

This work was supported by a grant from 2017 Research Funds of Andong National University. The X-ray crystallography experiment at PLS-II BL2D-SMC beamline was supported in part by MSIP and POSTECH.

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