Aqua(2,2'-di­amino-4,4'-bi-1,3-thia­zole-[kappa]²N,N')(imino­diacetato-[kappa]³O,N,O')­chromium(III) chloride mono­hydrate

Crystals of the title compound, [Cr(C₄H₅NO₄)(C₆H₆N₄S₂)(H₂O)]Cl·H₂O, consist of Cr^III complex cations, Cl^- counter-ions and lattice water mol­ecules. The complex cation assumes an octahedral coordination geometry, formed by a tridentate imino­di­acetate dianion (IDA), a di­amino­bi­thia­zole (DABT) mol­ecule and a water mol­ecule. The planar DABT group chelates the Cr^III ion with normal Cr-N distances [2.0574 (17) and 2.0598 (17) Å], but the DABT mol­ecule is inclined to the coordination plane by a dihedral angle of 17.23 (7)°. In the monodentate carboxylate groups of the IDA ion, the coordinated C-O bonds [1.288 (3) and 1.284 (3) Å] are much longer than the uncoordinated C-O bonds [1.222 (3) and 1.225 (3) Å].

S1. Comment

Metal complexes with 2,2'-diamino-4,4'-bi-1,3-thiazole (DABT) have potential applications in several fields. For example, a Co^II complex and a Ni^II complex with DABT have been found to be effective inhibitors of DNA synthesis of tumor cells (Waring, 1981; Fisher et al., 1985). As part of a series of structural investigations of metal complexes with DABT, the title Cr^III complex was prepared and its X-ray structure is presented here.

The molecular structure of (I) is shown in Fig. 1. The complex assumes an octahedral coordination geometry, formed by a DABT molecule, an iminodiacetate dianion (IDA) and a coordinated water molecule. The tridentate IDA dianion chelates to the Cr^III atom in a facial configuration, which is the common mode for IDA ligands in metal complexes (Mootz & Wunderlich, 1980; Subramaniam et al., 1994). Both chelating five-membered rings of the IDA ion display an envelope conformation, with atom N5 lying in the flap position and out-of the planes formed by the other four atoms by 0.220 (3) and 0.379 (3) Å, respectively. Carboxy groups of the IDA ion coordinate to the Cr^III atom in a monodentate manner. The uncoordinated carboxy O atoms are linked to adjacent coordinated water or lattice water molecules via hydrogen bonds, as shown in Fig. 1 and Table 2.

Within the carboxy groups, the C—O(coordinated) distances [1.288 (3) and 1.284 (3) Å] are much longer than the C—O(uncoordinated) distances [1.222 (3) and 1.225 (3) Å; Table 1]. The differences [0.066 (4) and 0.059 (4) Å] are comparable to that found in the neutral carboxyl group of iminodiacetic acid [0.078 (4) Å; Bernstein, 1979]. The differences in C—O distances are are essentially the same as that found in the Cr^III complex lithium difluoro(propanediamine-diacetato)chromium(III) [0.059 (4) Å; Bianchini et al., 1986].

The thiazole rings of the DABT molecule are approximately coplanar, the maximum atomic deviation being 0.0743 (12) Å (atom S2). It is notable that the planar DABT molecule chelating to a Cr^III atom is inclined to the coordination plane defined by aroms O1, O3, N1, N3 and Cr by a larger dihedral angle [17.23 (7) °]. Hence the Cr^III atom lies 0.402 (2) Å out of the DABT mean plane; however, the Cr—N(DABT) distances are normal. Although no geometry data for the DABT complex of Cr^III is available for comparison, the Cr—N3 [2.0574 (17) Å] and Cr—N1 [2.0598 (17) Å] distances are similar to the average Cr—N distances found in the 2,2'-bipyridine complex of Cr^III [2.064 (3) Å; Swaminathan et al., 1988] and the phenanthroline complex of Cr^III [2.065 (8) Å; Ohbo et al., 1983]. The C1—N2 [1.319 (3) Å] and C6—N4 [1.331 (3) Å] distances suggest the existence of electron delocalization between thiazole rings and amino groups.

Extensive hydrogen-bonding interactions occur in the crystal (Table 2). While the amino N atoms of the DABT molecule are intramolecularly hydrogen bonded to the coordinated carboxy O atoms, the Cl⁻ counter-ion and lattice water molecules are linked to the Cr^III complex cation via hydrogen bonds (Fig. 1). The Cl⁻ anion is simultaneously hydrogen bonded to the imino group of the IDA ion, the amino group of the DABT molecule and coordinated water molecules of adjacent complex cations, thus formng the hydrogen-bonded supramolecular structure shown in Fig. 2. The lattice water molecules are also involved in the supramolecular structure via hydrogen bonding to the carboxy group of the IDA ion and the amino group of the DABT molecule of neighboring complex cations. Three-centered hydrogen bonds occur in the crystal (Table 2), the sum of three angles about the H atoms being 354 (H2b) and 360 ° (H4a).

The neighboring parallel DABT planes are separated by 3.716 (7) Å, suggesting van der Waals contacts but not π–π stacking between DABT ligands in the crystal. Two symmetry-related O1W water molecules are loosely hydrogen bonded via atom H1B.

S2. Experimental

Microcrystals of DABT were obtained in the manner reported by Erlenmeyer (1948). An aqueous solution (20 ml) containing DABT (0.1 g, 0.5 mmol) and CrCl₃·6H₂O (0.13 g, 0.5 mmol) was mixed with another aqueous solution (10 ml) of IDA (0.07 g, 0.5 mmol) and NaOH (0.04 g, 1 mmol). The mixture was refluxed for 3 h and filtered. After the filtrate was cooled to room temperature, the filtrate was filtered once more. Green single crystals were obtained after 10 d.

S3. Refinement

H atoms on C atoms were placed in calculated positions, with C—H distances of 0.97 (methylene) and 0.93 Å (aromatic), and included in the final cycles of refinement in a riding model, with U_iso(H) values equal to 1.2U_eq of the carrier atoms. Other H atoms were located in a difference Fourier map and included in structure-factor calculation with fixed positional parameters and U_iso(h) values of 0.05 Ų.

Computing details

Data collection: PROCESS-AUTO (Rigaku Corporation, 1998); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC and Rigaku Corporation, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of (I), with 30% probability displacement ellipsoids. Dashed lines indicate hydrogen bonding. [Symmetric code: (iii) 1 − x,-y,-z.] Fig. 2. The hydrogen-bonding network between complex cations. [Symmetric codes: (i)1 − x,1 − y,1 − z; (v)1 + x,y,z; (vi)-1 + x,y, 1 + z.]

(I)

Crystal data

[Cr(C4H5NO4)(C6H6N4S2)(H2O)]Cl·H2O	Z = 2
Mr = 452.86	F(000) = 462
Triclinic, P1	Dx = 1.746 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.9449 (10) Å	Cell parameters from 3621 reflections
b = 10.7342 (11) Å	θ = 2.8–23.0°
c = 10.8835 (12) Å	µ = 1.10 mm^−1
α = 89.0403 (12)°	T = 295 K
β = 69.5740 (11)°	Plate, green
γ = 82.2042 (15)°	0.41 × 0.32 × 0.13 mm
V = 861.30 (17) Å^3

Data collection

Rigaku R-AXIS RAPID diffractometer	3069 independent reflections
Radiation source: fine-focus sealed tube	2862 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.013
Detector resolution: 10.00 pixels mm^-1	θmax = 25.2°, θmin = 1.9°
ω scans	h = −9→8
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −12→12
Tmin = 0.632, Tmax = 0.865	l = −13→13
6761 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.084	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0505P)^2 + 0.5018P] where P = (Fo^2 + 2Fc^2)/3
3069 reflections	(Δ/σ)max = 0.001
226 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.50 e Å^−3

Special details

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cr	0.49717 (4)	0.21837 (3)	0.17573 (3)	0.02755 (11)
Cl	0.93126 (7)	0.35286 (6)	0.32254 (6)	0.04820 (17)
S1	0.46519 (9)	0.61351 (6)	0.34671 (7)	0.04988 (18)
S2	0.91435 (8)	0.33112 (7)	−0.20953 (6)	0.04665 (17)
O1	0.3428 (2)	0.17489 (16)	0.34687 (16)	0.0416 (4)
O2	0.3276 (3)	0.1410 (2)	0.55162 (18)	0.0637 (5)
O3	0.56157 (19)	0.04228 (13)	0.11063 (15)	0.0332 (3)
O4	0.7771 (2)	−0.12294 (15)	0.06443 (18)	0.0491 (4)
O5	0.2868 (2)	0.24608 (15)	0.11541 (16)	0.0402 (4)
O1W	−0.0386 (4)	0.1265 (3)	0.5639 (3)	0.1019 (9)
N1	0.4789 (2)	0.40326 (16)	0.23256 (18)	0.0330 (4)
N2	0.2472 (3)	0.4381 (2)	0.4404 (2)	0.0479 (5)
N3	0.6699 (2)	0.28363 (16)	0.00607 (17)	0.0315 (4)
N4	0.7404 (3)	0.1282 (2)	−0.16230 (19)	0.0452 (5)
N5	0.7011 (2)	0.16649 (16)	0.25030 (16)	0.0299 (4)
C1	0.3856 (3)	0.4715 (2)	0.3431 (2)	0.0366 (5)
C2	0.6252 (4)	0.5799 (2)	0.1930 (3)	0.0455 (6)
H2	0.7084	0.6326	0.1477	0.055*
C3	0.6136 (3)	0.46720 (19)	0.1475 (2)	0.0350 (5)
C4	0.7181 (3)	0.4016 (2)	0.0228 (2)	0.0350 (5)
C5	0.8480 (3)	0.4394 (2)	−0.0808 (2)	0.0452 (6)
H5	0.8961	0.5141	−0.0830	0.054*
C6	0.7598 (3)	0.2365 (2)	−0.1144 (2)	0.0345 (5)
C11	0.4142 (3)	0.1549 (2)	0.4362 (2)	0.0415 (5)
C12	0.6164 (3)	0.1519 (3)	0.3929 (2)	0.0460 (6)
H12a	0.6430	0.2189	0.4390	0.055*
H12b	0.6693	0.0725	0.4168	0.055*
C13	0.8133 (3)	0.0509 (2)	0.1785 (3)	0.0448 (6)
H13a	0.8492	−0.0043	0.2392	0.054*
H13b	0.9225	0.0729	0.1124	0.054*
C14	0.7113 (3)	−0.0176 (2)	0.1135 (2)	0.0340 (5)
H	0.7770	0.2276	0.2377	0.050*
H1a	0.0501	0.1638	0.5490	0.050*
H1b	−0.0066	0.0559	0.6068	0.050*
H2a	0.1855	0.4853	0.5155	0.050*
H2b	0.1876	0.3750	0.4204	0.050*
H4a	0.6521	0.0858	−0.1156	0.050*
H4b	0.7978	0.1068	−0.2475	0.050*
H5a	0.1803	0.2629	0.1778	0.050*
H5b	0.2777	0.1961	0.0555	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr	0.02625 (18)	0.02613 (18)	0.02787 (19)	−0.00490 (13)	−0.00576 (13)	−0.00513 (13)
Cl	0.0336 (3)	0.0531 (4)	0.0512 (3)	−0.0097 (2)	−0.0041 (2)	−0.0227 (3)
S1	0.0585 (4)	0.0348 (3)	0.0604 (4)	−0.0026 (3)	−0.0264 (3)	−0.0188 (3)
S2	0.0429 (3)	0.0596 (4)	0.0343 (3)	−0.0194 (3)	−0.0053 (3)	0.0060 (3)
O1	0.0337 (8)	0.0471 (9)	0.0366 (8)	−0.0105 (7)	−0.0010 (7)	0.0009 (7)
O2	0.0658 (13)	0.0708 (13)	0.0355 (10)	−0.0067 (10)	0.0045 (9)	0.0094 (9)
O3	0.0324 (7)	0.0286 (7)	0.0394 (8)	−0.0062 (6)	−0.0123 (6)	−0.0059 (6)
O4	0.0569 (10)	0.0366 (9)	0.0559 (11)	0.0086 (8)	−0.0270 (9)	−0.0205 (8)
O5	0.0312 (8)	0.0453 (9)	0.0420 (9)	0.0008 (7)	−0.0118 (7)	−0.0159 (7)
O1W	0.0735 (16)	0.148 (3)	0.0625 (15)	−0.0186 (17)	0.0058 (13)	−0.0278 (16)
N1	0.0361 (9)	0.0280 (9)	0.0346 (9)	−0.0031 (7)	−0.0122 (8)	−0.0060 (7)
N2	0.0441 (11)	0.0506 (12)	0.0415 (11)	−0.0021 (9)	−0.0061 (9)	−0.0219 (9)
N3	0.0325 (9)	0.0304 (9)	0.0298 (9)	−0.0067 (7)	−0.0079 (7)	−0.0007 (7)
N4	0.0466 (11)	0.0490 (12)	0.0322 (10)	−0.0132 (9)	−0.0012 (9)	−0.0109 (8)
N5	0.0311 (8)	0.0282 (9)	0.0290 (9)	−0.0076 (7)	−0.0073 (7)	−0.0050 (7)
C1	0.0393 (12)	0.0321 (11)	0.0408 (12)	0.0029 (9)	−0.0194 (10)	−0.0121 (9)
C2	0.0530 (14)	0.0313 (12)	0.0559 (15)	−0.0111 (10)	−0.0215 (12)	−0.0023 (10)
C3	0.0409 (11)	0.0275 (10)	0.0409 (12)	−0.0058 (9)	−0.0192 (10)	0.0008 (9)
C4	0.0380 (11)	0.0309 (11)	0.0389 (12)	−0.0100 (9)	−0.0151 (10)	0.0042 (9)
C5	0.0508 (14)	0.0422 (13)	0.0458 (13)	−0.0187 (11)	−0.0167 (11)	0.0078 (11)
C6	0.0326 (11)	0.0401 (12)	0.0301 (11)	−0.0070 (9)	−0.0091 (9)	0.0014 (9)
C11	0.0487 (13)	0.0314 (11)	0.0332 (12)	−0.0059 (10)	−0.0001 (10)	−0.0009 (9)
C12	0.0500 (14)	0.0558 (15)	0.0298 (11)	−0.0083 (11)	−0.0108 (10)	0.0010 (10)
C13	0.0375 (12)	0.0475 (14)	0.0499 (14)	0.0059 (10)	−0.0193 (11)	−0.0221 (11)
C14	0.0370 (11)	0.0320 (11)	0.0310 (11)	−0.0035 (9)	−0.0098 (9)	−0.0061 (8)

Geometric parameters (Å, º)

Cr—O1	1.9294 (16)	N2—H2a	0.912
Cr—O3	1.9662 (14)	N2—H2b	0.946
Cr—O5	1.9843 (15)	N3—C6	1.325 (3)
Cr—N3	2.0574 (17)	N3—C4	1.404 (3)
Cr—N1	2.0598 (17)	N4—C6	1.331 (3)
Cr—N5	2.0620 (18)	N4—H4a	0.887
S1—C2	1.719 (3)	N4—H4b	0.897
S1—C1	1.734 (2)	N5—C12	1.476 (3)
S2—C5	1.722 (3)	N5—C13	1.480 (3)
S2—C6	1.740 (2)	N5—H	0.927
O1—C11	1.288 (3)	C2—C3	1.342 (3)
O2—C11	1.222 (3)	C2—H2	0.930
O3—C14	1.284 (3)	C3—C4	1.454 (3)
O4—C14	1.225 (3)	C4—C5	1.337 (3)
O5—H5a	0.878	C5—H5	0.930
O5—H5b	0.880	C11—C12	1.504 (4)
O1W—H1a	0.823	C12—H12a	0.970
O1W—H1b	0.936	C12—H12b	0.970
N1—C1	1.339 (3)	C13—C14	1.509 (3)
N1—C3	1.400 (3)	C13—H13a	0.970
N2—C1	1.319 (3)	C13—H13b	0.970
O1—Cr—O3	93.03 (7)	C13—N5—H	107.2
O1—Cr—O5	90.70 (7)	Cr—N5—H	111.6
O3—Cr—O5	92.79 (6)	N2—C1—N1	125.4 (2)
O1—Cr—N3	172.33 (7)	N2—C1—S1	122.00 (16)
O3—Cr—N3	93.34 (7)	N1—C1—S1	112.58 (17)
O5—Cr—N3	93.25 (7)	C3—C2—S1	110.69 (19)
O1—Cr—N1	93.16 (7)	C3—C2—H2	124.7
O3—Cr—N1	169.77 (7)	S1—C2—H2	124.7
O5—Cr—N1	95.27 (7)	C2—C3—N1	115.1 (2)
N3—Cr—N1	79.93 (7)	C2—C3—C4	130.0 (2)
O1—Cr—N5	83.41 (7)	N1—C3—C4	114.91 (18)
O3—Cr—N5	81.81 (6)	C5—C4—N3	115.0 (2)
O5—Cr—N5	171.75 (7)	C5—C4—C3	129.5 (2)
N3—Cr—N5	93.28 (7)	N3—C4—C3	115.36 (18)
N1—Cr—N5	90.82 (7)	C4—C5—S2	110.82 (18)
C2—S1—C1	90.48 (11)	C4—C5—H5	124.6
C5—S2—C6	89.97 (11)	S2—C5—H5	124.6
C11—O1—Cr	117.65 (14)	N3—C6—N4	125.7 (2)
C14—O3—Cr	117.62 (13)	N3—C6—S2	113.00 (16)
Cr—O5—H5a	115.35	N4—C6—S2	121.26 (16)
Cr—O5—H5b	121.35	O2—C11—O1	124.0 (2)
H5a—O5—H5b	108.98	O2—C11—C12	119.5 (2)
H1a—O1W—H1b	101.4	O1—C11—C12	116.51 (19)
C1—N1—C3	111.14 (18)	N5—C12—C11	112.72 (19)
C1—N1—Cr	134.06 (16)	N5—C12—H12a	109.0
C3—N1—Cr	113.78 (13)	C11—C12—H12a	109.0
C1—N2—H2a	124.5	N5—C12—H12b	109.0
C1—N2—H2b	116.4	C11—C12—H12b	109.0
H2a—N2—H2b	116.5	H12a—C12—H12b	107.8
C6—N3—C4	111.07 (18)	N5—C13—C14	111.43 (18)
C6—N3—Cr	135.14 (15)	N5—C13—H13a	109.3
C4—N3—Cr	113.51 (14)	C14—C13—H13a	109.3
C6—N4—H4a	119.8	N5—C13—H13b	109.3
C6—N4—H4b	120.2	C14—C13—H13b	109.3
H4a—N4—H4b	118.5	H13a—C13—H13b	108.0
C12—N5—C13	113.95 (19)	O4—C14—O3	124.6 (2)
C12—N5—Cr	108.06 (14)	O4—C14—C13	119.1 (2)
C13—N5—Cr	108.38 (13)	O3—C14—C13	116.24 (18)
C12—N5—H	107.8

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N5—H···Cl	0.93	2.33	3.1634 (19)	149
O1W—H1a···O2	0.82	2.20	2.891 (4)	142
N2—H2a···Cl^i	0.91	2.35	3.237 (2)	165
N2—H2b···Cl^ii	0.95	2.64	3.420 (3)	140
N2—H2b···O1	0.95	2.33	2.927 (3)	121
N4—H4a···O3	0.89	2.37	3.002 (3)	128
N4—H4a···O3^iii	0.89	2.31	3.104 (3)	149
N4—H4b···O1W^iv	0.90	2.04	2.882 (4)	157
O5—H5a···Cl^ii	0.88	2.16	3.0230 (18)	166
O5—H5b···O4^iii	0.88	1.74	2.607 (3)	168

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