Crystal structure of tris­[4-(di­methyl­amino)­pyridinium] tris­(oxalato-κ2O,O′)chromate(III) tetra­hydrate

Makon ma Houga, N.; Capet, F.; Nenwa, J.; Bebga, G.; Foulon, M.

doi:10.1107/S2056989015020113

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ISSN: 2056-9890

Volume 71| Part 11| November 2015| Pages 1408-1410

https://doi.org/10.1107/S2056989015020113

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Crystal structure of tris[4-(dimethylamino)pyridinium] tris(oxalato-κ²O,O′)chromate(III) tetrahydrate

Noé Makon ma Houga,^a Frédéric Capet,^b Justin Nenwa,^a ^* Gouet Bebga ^c and Michel Foulon ^d

^aDepartment of Inorganic Chemistry, University of Yaounde 1, POB 812 Yaounde, Cameroon, ^bUnité de Catalyse et de Chimie du Solide, UMR 8181, Ecole Nationale Supérieure de Chimie de Lille, Université Lille1, 59650 Villeneuve d'Ascq Cedex, France, ^cHigher Teacher Training College, Chemistry Department, University of Yaounde 1, POB 47, Yaounde, Cameroon, and ^dUFR de Physique, Université Lille1, 59650 Villeneuve d'Ascq Cedex, France
^*Correspondence e-mail: jnenwa@yahoo.fr

Edited by M. Weil, Vienna University of Technology, Austria (Received 14 October 2015; accepted 24 October 2015; online 31 October 2015)

In the title hybrid salt, (C₇H₁₁N₂)₃[Cr(C₂O₄)₃]·4H₂O, the central Cr^III ion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2−) ligands in a slightly distorted octahedral coordination sphere. The Cr—O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O—Cr—O angles range from 82.11 (6) to 93.41 (5)°. The 4-(dimethylamino)pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. π–π interactions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å.

Keywords: crystal structure; 4-(dimethylamino)pyridine; tris(oxalato)chromate(III); hybrid salt; hydrogen bonding; π–π interactions.

CCDC reference: 1400490

1. Chemical context

The coordination chemistry of oxalate (C₂O₄²⁻) continues to receive considerable attention because of the ability of this ion to act as a remarkably flexible ligand system in complexations with a wide range of metal ions (Martin et al., 2007 ). Over the last decade, Bélombé and coworkers (Bélombé et al., 2003 ) prepared a novel barium-oxalatochromate(III), {Ba₆(H₂O)₁₇[Cr(ox)₃]₄}·7H₂O, and demonstrated the use of this complex as a suitable precursor for the synthesis of multi-functional crystalline materials (Bélombé et al., 2009a ,b ; Mbiangué et al., 2012 ). Moreover, this complex has received much attention in the field of materials science for its use as a convenient route for the preparation of technologically important metallic composite oxides (Neo et al., 2006 ). As part of our ongoing research program, we have now combined this versatile barium-oxalatochromate(III) complex with 4-(dimethylamino)pyridinium oxalate to isolate the organic–inorganic hybrid salt, (C₇H₁₁N₂)₃[Cr(C₂O₄)₃]·4H₂O.

2. Structural commentary

The molecular components of the title compound are shown in Fig. 1. The asymmetric unit contains one and a half 4-(dimethylamino)pyridinium cations, one half of the tris(oxalato)chromate(III) complex anion and two lattice water molecules. The entities are completed by application of twofold rotation symmetry. The central Cr^III ion of the complex anion is coordinated by six O atoms from three chelating oxalato(2−) ligands in a slightly distorted (2 + 2 + 2) octahedral coordination sphere. The chelate O—Cr—O angles range from 82.11 (6) to 93.41 (5)°. The Cr—O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å and are similar to those found in the guanidinium tris(oxalato)chromate(III) salt (Golič & Bulc, 1988 ). Bond lengths and angles in the organic cations, [C₇H₁₁N₂]⁺, are in agreement with those found in salts with the same cationic entity (Nenwa et al., 2010 ; Ghouili et al., 2010 ; Benslimane et al., 2012 ; Ben Nasr et al., 2015 ).

Figure 1
The molecular components of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines. [Symmetry codes: (i) 1 − x, y, $[{1\over 2}]$ − z; (ii) − $[{1\over 2}]$ + x, $[{1\over 2}]$ − y, − $[{1\over 2}]$ + z; (iii) $[{3\over 2}]$ − x, $[{1\over 2}]$ − y, 1 − z; (iv) $[{3\over 2}]$ − x, − $[{1\over 2}]$ + y, $[{1\over 2}]$ − z; (v) − $[{1\over 2}]$ + x, − $[{1\over 2}]$ + y, z.]

3. Supramolecular features

In the title compound, the crystal packing is stabilized by a network of intermolecular N—H⋯O and O—H⋯O hydrogen bonds linking the coordination octahedra, 4-(dimethylamino)pyridinium cations and lattice water molecules (Table 1, Fig. 2). In addition, π–π stacking interactions [centroid-to-centroid distances of 3.541 (1) and 3.575 (1) Å] between the pyridine rings contribute to the stabilization of the three-dimensional network (Fig. 3).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O8Wⁱ	0.91 (2)	1.84 (2)	2.702 (2)	157.8 (19)
N3—H3⋯O6ⁱⁱ	0.92 (4)	2.12 (3)	2.879 (3)	139 (1)
N3—H3⋯O6ⁱⁱⁱ	0.92 (4)	2.12 (3)	2.879 (3)	139 (1)
O7W—H7WA⋯O4^iv	0.83 (1)	1.99 (1)	2.819 (2)	178 (3)
O7W—H7WB⋯O1^v	0.82 (1)	2.12 (1)	2.9079 (19)	161 (3)
O8W—H8WA⋯O7W	0.81 (1)	1.95 (1)	2.7578 (19)	172 (3)
O8W—H8WB⋯O6^vi	0.82 (1)	1.99 (1)	2.8007 (19)	175 (3)
Symmetry codes: (i) $[x-{\script{1\over 2}}, y-{\script{1\over 2}}, z]$ ; (ii) $[-x+1, y+1, -z+{\script{1\over 2}}]$ ; (iii) x, y+1, z; (iv) $[-x+1, y, -z+{\script{1\over 2}}]$ ; (v) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (vi) $[x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ .

Figure 2
Projection on the ab plane of the crystal structure of the title compound. Hydrogen bonds are shown as dashed lines.

Figure 3
π–π stacking interactions (dashed lines) between adjacent organic cations in the title compound.

4. Synthesis and crystallization

The title compound was obtained by reaction of an aqueous solution of the freshly prepared barium-oxalatochromate(III) salt {Ba₆(H₂O)₁₇[Cr(C₂O₄)₃]₄}·7H₂O (1 mmol, 2.536 g), with an aqueous solution of 4-(dimethylamino)pyridine (12 mmol, 1.464 g) and oxalic acid (6 mmol, 0.756 g). The mixture was stirred at 333 K for about 30 minutes and then cooled to room temperature and filtered. The title compound crystallized by slow evaporation of the solvent at room temperature in form of light-violet crystals with dimensions up to 3 mm within a few weeks.

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. H atoms bonded to C atoms were positioned geometrically and allowed to ride on their parent atoms with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for aromatic and 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl H atoms. H atoms of water molecules as well as those bonded to N atoms were located from a difference Fourier map. Water H atoms were refined with soft restraints on O—H and H⋯H distances [O—H = 0.82 (1) Å and H⋯H = 1.30 (2) Å] and U_iso(H) = 1.5U_eq(O) whereas H atoms bonded to N atoms were refined freely.

Table 2
Experimental details

Crystal data
Chemical formula	(C₇H₁₁N₂)₃[Cr(C₃O₄)₃]·4H₂O
M_r	757.66
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	19.1141 (5), 16.7537 (4), 11.0053 (2)
β (°)	98.803 (1)
V (Å³)	3482.73 (14)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.41
Crystal size (mm)	0.58 × 0.21 × 0.14

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.708, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	56955, 5322, 3757
R_int	0.038
(sin θ/λ)_max (Å⁻¹)	0.714

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.120, 1.03
No. of reflections	5322
No. of parameters	249
No. of restraints	6
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.42
Computer programs: SAINT and APEX2 (Bruker, 2014 ), SHELXS97 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), OLEX2 (Dolomanov et al., 2009 ), publCIF (Westrip, 2010 ) and PLATON (Spek, 2009 ).

Supporting information

CCDC reference: 1400490

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989015020113/wm5230sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989015020113/wm5230Isup2.hkl

checkCIF report

Computing details top

Data collection: SAINT (Bruker, 2014); cell refinement: APEX2 (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009), publCIF (Westrip, 2010) and PLATON (Spek, 2009).

Tris[4-(dimethylamino)pyridinium] tris(oxalato-κ²O,O')chromate(III) tetrahydrate top

Crystal data top

(C₇H₁₁N₂)₃[Cr(C₃O₄)₃]·4H₂O	F(000) = 1588
M_r = 757.66	D_x = 1.445 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 19.1141 (5) Å	Cell parameters from 9987 reflections
b = 16.7537 (4) Å	θ = 2.4–27.8°
c = 11.0053 (2) Å	µ = 0.41 mm⁻¹
β = 98.803 (1)°	T = 296 K
V = 3482.73 (14) Å³	Prism, violet
Z = 4	0.58 × 0.21 × 0.14 mm

Data collection top

Bruker APEXII CCD diffractometer	3757 reflections with I > 2σ(I)
Radiation source: sealed X-ray tube	R_int = 0.038
φ and ω scans	θ_max = 30.5°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −27→27
T_min = 0.708, T_max = 0.746	k = −23→23
56955 measured reflections	l = −15→15
5322 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.038	Hydrogen site location: mixed
wR(F²) = 0.120	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.056P)² + 1.554P] where P = (F_o² + 2F_c²)/3
5322 reflections	(Δ/σ)_max = 0.001
249 parameters	Δρ_max = 0.23 e Å⁻³
6 restraints	Δρ_min = −0.42 e Å⁻³

Special details top

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

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

	x	y	z	U_iso*/U_eq
Cr1	0.5000	0.25122 (2)	0.2500	0.04246 (11)
O2	0.44865 (6)	0.33279 (7)	0.32829 (9)	0.0502 (3)
O1	0.41659 (6)	0.25871 (7)	0.12056 (10)	0.0521 (3)
O5	0.45866 (6)	0.16208 (7)	0.33354 (10)	0.0522 (3)
O7W	0.82663 (8)	0.36686 (8)	0.49953 (15)	0.0698 (4)
O6	0.45686 (8)	0.02935 (8)	0.34038 (13)	0.0695 (4)
O3	0.35256 (8)	0.40942 (8)	0.29279 (12)	0.0714 (4)
N2	0.28924 (8)	0.40160 (8)	0.65828 (12)	0.0507 (3)
O8W	0.87475 (9)	0.52183 (8)	0.53015 (16)	0.0762 (4)
N1	0.33363 (7)	0.16521 (9)	0.60672 (13)	0.0499 (3)
O4	0.31735 (7)	0.32756 (9)	0.06984 (14)	0.0767 (4)
N3	0.5000	0.87873 (15)	0.2500	0.0615 (5)
C6	0.30440 (7)	0.32468 (9)	0.64377 (12)	0.0405 (3)
N4	0.5000	0.63400 (15)	0.2500	0.0730 (7)
C1	0.39125 (9)	0.35760 (9)	0.26335 (14)	0.0475 (3)
C7	0.34073 (8)	0.29953 (10)	0.54716 (12)	0.0442 (3)
H7	0.3556	0.3370	0.4943	0.053*
C2	0.37147 (9)	0.31285 (10)	0.13931 (15)	0.0496 (4)
C5	0.28590 (9)	0.26379 (10)	0.72219 (14)	0.0483 (4)
H5	0.2636	0.2770	0.7888	0.058*
C3	0.47543 (8)	0.09271 (10)	0.30033 (14)	0.0486 (4)
C4	0.30043 (9)	0.18699 (11)	0.70089 (14)	0.0521 (4)
H4	0.2872	0.1478	0.7527	0.063*
C12	0.5000	0.71391 (15)	0.2500	0.0505 (5)
C8	0.35377 (8)	0.22127 (10)	0.53192 (14)	0.0476 (3)
H8	0.3773	0.2057	0.4679	0.057*
C10	0.30788 (12)	0.46256 (11)	0.57456 (17)	0.0626 (5)
H10A	0.3583	0.4633	0.5769	0.094*
H10B	0.2924	0.5138	0.5991	0.094*
H10C	0.2853	0.4508	0.4925	0.094*
C13	0.47586 (10)	0.75888 (12)	0.34435 (16)	0.0563 (4)
H13	0.4593	0.7330	0.4091	0.068*
C14	0.47685 (9)	0.83913 (12)	0.34033 (17)	0.0608 (4)
H14	0.4608	0.8678	0.4030	0.073*
C9	0.25007 (13)	0.42746 (13)	0.75514 (19)	0.0741 (6)
H9A	0.2037	0.4041	0.7419	0.111*
H9B	0.2460	0.4846	0.7537	0.111*
H9C	0.2748	0.4108	0.8336	0.111*
C11	0.47408 (17)	0.58935 (16)	0.3474 (3)	0.1074 (10)
H11A	0.5028	0.6012	0.4247	0.161*
H11B	0.4764	0.5332	0.3310	0.161*
H11C	0.4259	0.6041	0.3509	0.161*
H3	0.5000	0.934 (2)	0.2500	0.091 (11)*
H7WA	0.7843 (7)	0.3544 (19)	0.481 (3)	0.136*
H8WA	0.8595 (16)	0.4767 (9)	0.528 (3)	0.136*
H8WB	0.8988 (14)	0.5268 (17)	0.475 (2)	0.136*
H7WB	0.8432 (14)	0.3280 (13)	0.540 (3)	0.136*
H1	0.3406 (11)	0.1122 (13)	0.5955 (18)	0.068 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cr1	0.04232 (19)	0.0513 (2)	0.03681 (16)	0.000	0.01578 (13)	0.000
O2	0.0557 (6)	0.0565 (7)	0.0411 (5)	0.0033 (5)	0.0164 (5)	−0.0054 (4)
O1	0.0505 (6)	0.0617 (7)	0.0445 (6)	−0.0005 (5)	0.0087 (5)	−0.0094 (5)
O5	0.0572 (7)	0.0538 (6)	0.0530 (6)	−0.0008 (5)	0.0318 (5)	−0.0011 (5)
O7W	0.0775 (9)	0.0497 (7)	0.0849 (10)	−0.0032 (7)	0.0211 (8)	−0.0005 (7)
O6	0.0851 (9)	0.0556 (7)	0.0795 (9)	−0.0022 (7)	0.0499 (8)	0.0054 (6)
O3	0.0916 (10)	0.0639 (8)	0.0653 (8)	0.0297 (7)	0.0330 (7)	0.0100 (6)
N2	0.0646 (8)	0.0478 (7)	0.0431 (6)	−0.0014 (6)	0.0191 (6)	−0.0055 (5)
O8W	0.0914 (11)	0.0531 (8)	0.0954 (11)	−0.0067 (7)	0.0501 (9)	−0.0132 (7)
N1	0.0509 (7)	0.0481 (8)	0.0498 (7)	0.0025 (6)	0.0041 (6)	−0.0044 (6)
O4	0.0598 (8)	0.0853 (10)	0.0794 (9)	0.0068 (7)	−0.0076 (7)	0.0037 (8)
N3	0.0568 (12)	0.0558 (13)	0.0701 (14)	0.000	0.0036 (10)	0.000
C6	0.0399 (7)	0.0492 (8)	0.0323 (6)	−0.0036 (6)	0.0057 (5)	−0.0039 (5)
N4	0.0845 (17)	0.0570 (13)	0.0703 (14)	0.000	−0.0111 (12)	0.000
C1	0.0565 (9)	0.0447 (8)	0.0467 (8)	0.0018 (7)	0.0250 (7)	0.0078 (6)
C7	0.0462 (8)	0.0530 (8)	0.0351 (6)	−0.0040 (6)	0.0123 (6)	−0.0008 (6)
C2	0.0469 (8)	0.0526 (9)	0.0512 (8)	−0.0051 (7)	0.0132 (7)	0.0065 (7)
C5	0.0542 (9)	0.0568 (9)	0.0363 (7)	−0.0040 (7)	0.0150 (6)	−0.0003 (6)
C3	0.0462 (8)	0.0569 (9)	0.0469 (8)	−0.0014 (7)	0.0205 (6)	0.0010 (7)
C4	0.0598 (10)	0.0540 (9)	0.0431 (8)	−0.0056 (7)	0.0098 (7)	0.0052 (7)
C12	0.0461 (12)	0.0573 (14)	0.0448 (11)	0.000	−0.0033 (9)	0.000
C8	0.0435 (8)	0.0603 (9)	0.0401 (7)	0.0017 (7)	0.0097 (6)	−0.0075 (6)
C10	0.0877 (14)	0.0462 (9)	0.0567 (10)	−0.0061 (9)	0.0197 (9)	−0.0016 (7)
C13	0.0509 (9)	0.0763 (13)	0.0430 (8)	−0.0002 (8)	0.0113 (7)	0.0062 (7)
C14	0.0546 (10)	0.0712 (12)	0.0572 (10)	0.0095 (9)	0.0107 (8)	−0.0094 (8)
C9	0.1006 (16)	0.0638 (12)	0.0665 (11)	0.0046 (11)	0.0406 (11)	−0.0154 (9)
C11	0.127 (2)	0.0759 (16)	0.108 (2)	−0.0233 (15)	−0.0179 (17)	0.0327 (14)

Geometric parameters (Å, º) top

Cr1—O2ⁱ	1.9577 (11)	C6—C5	1.416 (2)
Cr1—O2	1.9577 (11)	N4—C12	1.339 (3)
Cr1—O1ⁱ	1.9728 (12)	N4—C11	1.455 (3)
Cr1—O1	1.9728 (12)	N4—C11ⁱ	1.455 (3)
Cr1—O5ⁱ	1.9804 (11)	C1—C2	1.553 (2)
Cr1—O5	1.9804 (11)	C7—H7	0.9300
O2—C1	1.2834 (19)	C7—C8	1.350 (2)
O1—C2	1.290 (2)	C5—H5	0.9300
O5—C3	1.274 (2)	C5—C4	1.344 (2)
O7W—H7WA	0.830 (10)	C3—C3ⁱ	1.558 (3)
O7W—H7WB	0.822 (10)	C4—H4	0.9300
O6—C3	1.223 (2)	C12—C13ⁱ	1.416 (2)
O3—C1	1.2162 (19)	C12—C13	1.416 (2)
N2—C6	1.336 (2)	C8—H8	0.9300
N2—C10	1.456 (2)	C10—H10A	0.9600
N2—C9	1.459 (2)	C10—H10B	0.9600
O8W—H8WA	0.810 (10)	C10—H10C	0.9600
O8W—H8WB	0.818 (10)	C13—H13	0.9300
N1—C4	1.346 (2)	C13—C14	1.345 (3)
N1—C8	1.343 (2)	C14—H14	0.9300
N1—H1	0.91 (2)	C9—H9A	0.9600
O4—C2	1.214 (2)	C9—H9B	0.9600
N3—C14ⁱ	1.326 (2)	C9—H9C	0.9600
N3—C14	1.326 (2)	C11—H11A	0.9600
N3—H3	0.92 (4)	C11—H11B	0.9600
C6—C7	1.4200 (19)	C11—H11C	0.9600

O2ⁱ—Cr1—O2	91.45 (7)	O4—C2—O1	124.63 (17)
O2—Cr1—O1	82.48 (5)	O4—C2—C1	121.68 (16)
O2—Cr1—O1ⁱ	92.41 (5)	C6—C5—H5	119.8
O2ⁱ—Cr1—O1	92.41 (5)	C4—C5—C6	120.39 (15)
O2ⁱ—Cr1—O1ⁱ	82.47 (5)	C4—C5—H5	119.8
O2—Cr1—O5ⁱ	173.35 (5)	O5—C3—C3ⁱ	114.17 (8)
O2—Cr1—O5	93.41 (5)	O6—C3—O5	126.08 (14)
O2ⁱ—Cr1—O5	173.35 (5)	O6—C3—C3ⁱ	119.75 (9)
O2ⁱ—Cr1—O5ⁱ	93.41 (5)	N1—C4—H4	119.1
O1—Cr1—O1ⁱ	172.70 (7)	C5—C4—N1	121.88 (15)
O1—Cr1—O5ⁱ	92.78 (5)	C5—C4—H4	119.1
O1ⁱ—Cr1—O5	92.79 (5)	N4—C12—C13	122.15 (11)
O1—Cr1—O5	92.72 (5)	N4—C12—C13ⁱ	122.15 (11)
O1ⁱ—Cr1—O5ⁱ	92.72 (5)	C13—C12—C13ⁱ	115.7 (2)
O5ⁱ—Cr1—O5	82.11 (6)	N1—C8—C7	121.82 (14)
C1—O2—Cr1	115.12 (10)	N1—C8—H8	119.1
C2—O1—Cr1	114.55 (10)	C7—C8—H8	119.1
C3—O5—Cr1	114.77 (9)	N2—C10—H10A	109.5
H7WA—O7W—H7WB	102 (2)	N2—C10—H10B	109.5
C6—N2—C10	121.50 (13)	N2—C10—H10C	109.5
C6—N2—C9	121.25 (15)	H10A—C10—H10B	109.5
C10—N2—C9	117.18 (15)	H10A—C10—H10C	109.5
H8WA—O8W—H8WB	108 (2)	H10B—C10—H10C	109.5
C4—N1—H1	117.7 (13)	C12—C13—H13	120.0
C8—N1—C4	119.70 (15)	C14—C13—C12	119.98 (17)
C8—N1—H1	122.5 (13)	C14—C13—H13	120.0
C14—N3—C14ⁱ	120.0 (3)	N3—C14—C13	122.18 (19)
C14ⁱ—N3—H3	120.02 (13)	N3—C14—H14	118.9
C14—N3—H3	120.01 (13)	C13—C14—H14	118.9
N2—C6—C7	121.05 (14)	N2—C9—H9A	109.5
N2—C6—C5	122.92 (13)	N2—C9—H9B	109.5
C5—C6—C7	116.04 (14)	N2—C9—H9C	109.5
C12—N4—C11ⁱ	120.94 (15)	H9A—C9—H9B	109.5
C12—N4—C11	120.93 (15)	H9A—C9—H9C	109.5
C11ⁱ—N4—C11	118.1 (3)	H9B—C9—H9C	109.5
O2—C1—C2	113.93 (13)	N4—C11—H11A	109.5
O3—C1—O2	125.85 (16)	N4—C11—H11B	109.5
O3—C1—C2	120.19 (15)	N4—C11—H11C	109.5
C6—C7—H7	119.9	H11A—C11—H11B	109.5
C8—C7—C6	120.14 (14)	H11A—C11—H11C	109.5
C8—C7—H7	119.9	H11B—C11—H11C	109.5
O1—C2—C1	113.67 (13)

Cr1—O2—C1—O3	−177.75 (14)	C7—C6—C5—C4	−2.3 (2)
Cr1—O2—C1—C2	4.37 (16)	C5—C6—C7—C8	2.0 (2)
Cr1—O1—C2—O4	178.94 (14)	C4—N1—C8—C7	−1.0 (2)
Cr1—O1—C2—C1	−2.76 (16)	C12—C13—C14—N3	−0.1 (3)
Cr1—O5—C3—O6	179.09 (15)	C8—N1—C4—C5	0.7 (2)
Cr1—O5—C3—C3ⁱ	−0.6 (2)	C10—N2—C6—C7	1.3 (2)
O2—C1—C2—O1	−1.05 (19)	C10—N2—C6—C5	−178.85 (16)
O2—C1—C2—O4	177.30 (15)	C13ⁱ—C12—C13—C14	0.02 (12)
O3—C1—C2—O1	−179.06 (15)	C14ⁱ—N3—C14—C13	0.03 (13)
O3—C1—C2—O4	−0.7 (2)	C9—N2—C6—C7	178.16 (16)
N2—C6—C7—C8	−178.10 (14)	C9—N2—C6—C5	−2.0 (3)
N2—C6—C5—C4	177.81 (15)	C11ⁱ—N4—C12—C13	−179.27 (16)
C6—C7—C8—N1	−0.4 (2)	C11ⁱ—N4—C12—C13ⁱ	0.74 (16)
C6—C5—C4—N1	1.0 (3)	C11—N4—C12—C13ⁱ	−179.26 (16)
N4—C12—C13—C14	−179.98 (12)	C11—N4—C12—C13	0.74 (16)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O8Wⁱⁱ	0.91 (2)	1.84 (2)	2.702 (2)	157.8 (19)
N3—H3···O6ⁱⁱⁱ	0.92 (4)	2.12 (3)	2.879 (3)	139 (1)
N3—H3···O6^iv	0.92 (4)	2.12 (3)	2.879 (3)	139 (1)
O7W—H7WA···O4ⁱ	0.83 (1)	1.99 (1)	2.819 (2)	178 (3)
O7W—H7WB···O1^v	0.82 (1)	2.12 (1)	2.9079 (19)	161 (3)
O8W—H8WA···O7W	0.81 (1)	1.95 (1)	2.7578 (19)	172 (3)
O8W—H8WB···O6^vi	0.82 (1)	1.99 (1)	2.8007 (19)	175 (3)

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

Acknowledgements

The authors are grateful to Professor Simeon Kouam Fogue (Higher Teacher Training College, Chemistry Department, University of Yaounde 1) for the donation of 4-(dimethylamino)pyridine. The Fonds Européen de Développement Régional (FEDER), CNRS, Région Nord Pas-de-Calais and Ministère de l'Education Nationale de l'Enseignement Supérieur et de la Recherche are acknowledged for funding of X-ray diffractometers.

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