catena-Poly[[bis(3-amino­benzoic acid-κN)­cadmium(II)]-di-μ-thio­cyanato-κ⁴N:S;S:N]

The title compound, [Cd(μ-SCN)₂(C₇H₇NO₂)₂]_n, has been prepared from the reaction of 3-amino­benzoic acid, NH₄SCN and Cd(NO₃)₂·6H₂O in MeOH/H₂O. It consists of one-dimensional polymeric chains, which are extended into a two-dimensional layer structure by head-to-head hydrogen bonds involving carboxyl groups from adjacent chains.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.069
• wR factor = 0.042
• Data-to-parameter ratio = 13.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_420  Alert C D-H Without Acceptor       N(11)  -   H(11A)            ?

PLAT_420  Alert C D-H Without Acceptor       N(21)  -   H(21A)            ?


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

---

S1. Comment

Crystal engineering of inorganic/organic hybrid materials is currently of great interest, owing to their interesting structural topologies and potential application in material science, such as ion-exchange, adsorption, molecular recognition, catalysis and magnetism (Aakeroy et al., 1999; Hagrman et al., 1999). Considerable effort has been devoted to supramolecular networks organized and held together by means of coordination covalent bonds, hydrogen bonds, and their combination, because of the strength, directionality and complementarity of coordination bonds and hydrogen bonds, as well as extensive applications of hydrogen-bonded complexes in crystal engineering (Carlucci et al., 1997; Dong et al., 2000; Moulton & Zaworotko, 2001). A number of promising supramolecular complexes have been designed and constructed from mononuclear (Kuehl et al., 2001; Pan et al., 2001) or polynuclear coordination complexes (Copp et al., 1993; Liang et al., 2001) and lower-dimensional coordination polymers (Chen & Chen, 2002; Dong et al., 2000; Goher & Mautner, 2001; Prior & Rosseinsky, 2001) through using hydrogen bonds as linkers. Here we report a hydrogen-bonded two-dimensional complex, [Cd(µ-SCN-N,S)₂(HL)₂]_n (HL = 3-aminobenzoic acid), constructed from one-dimensional polymeric chains via head-to-head carboxylic acid hydrogen bonds.

The single-crystal X-ray diffraction analysis reveals that the title compound contains HL ligands attached to polymeric cadmium-thiocyanate chains in a trans arrangement. As shown in Fig. 1, each Cd(II) is in a distorted octahedral environment and is coordinated by two nitrogen atoms from HL ligands, two independent thiocyanate sulfur atoms and another two thiocyanate nitrogen atoms. Each pair of adjacent Cd(II) atoms is bridged by two independent SCN^- ligands to form a one-dimensional cadmium-thiocyanate chain consisting of eight-membered (N—C—S—Cd)₂ rings. The Cd···Cd separation in the eight-membered rings is 5.8547 (2) Å, which is close to those in cadmium-thiocyanate chains (Chen et al., 1999; Chen & Chen, 2002; Taniguchi et al., 1986; Taniguchi et al., 1987). The bond distances of Cd—N_HL [2.249 (5) and 2.296 (5) Å] are longer than that of Cd—N_SCN [2.375 (4) and 2.386 (4) Å]. The bond distances of Cd—S are 2.7001 (14) and 2.8054 (14) Å, comparable with those in the above cadmium-thiocyanate complexes. The remaining two positions around the six-coordinate Cd(II) centers in the polymeric chain are occupied by nitrogen atoms of two independent HL ligands with a N11—Cd—N21 bond angle of 170.50 (2)°. The carboxylic acid groups in the HL ligands are connected via head-to-head O—H···O hydrogen bonds [R₂²(8) in graph set notation (Bernstein et al., 1995)], connecting one-dimensional [Cd(SCN)₂(HL)₂]_n chains into an infinite two-dimensional layer structure. There are no short contacts or noteworthy aryl-aryl interactions between adjacent chains or between neighboring layers.

S2. Experimental

A solution of Cd(NO₃)₂·6H₂O (0.15 g, 0.5 mmol) and NH₄SCN (0.08 g, 1 mmol) in H₂O (5 ml) was added slowly to a solution of HL (0.07 g, 0.5 mmol) in MeOH (10 ml). The reaction mixture was stirred for 30 min. and gave a colorless solution, which was filtered. Pale yellow crystals of the title compound were obtained by leaving the resulting solution in air for 2–3 weeks.

S3. Refinement

The positions of hydrogen atoms were generated geometrically (C—H = 0.93–0.96, N—H = 0.90, O—H = 0.82 Å), assigned isotropic displacement parameters and allowed to ride on their parent atoms.

Computing details

Data collection: SMART (Siemens, 1994); cell refinement: SMART; data reduction: SAINT (Siemens, 1994); program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A section of the one-dimensional chain of the title compound. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Hydrogen bonds between adjacent chains, forming a two-dimensional layer.

(I)

Crystal data

C16H14CdN4O4S2	F(000) = 1000
Mr = 502.83	Dx = 1.740 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 14.6733 (1) Å	Cell parameters from 82 reflections
b = 5.8547 (2) Å	θ = 1.7–25.0°
c = 22.3503 (5) Å	µ = 1.38 mm^−1
β = 90.730 (2)°	T = 293 K
V = 1919.91 (8) Å^3	Plate, pale yellow
Z = 4	0.50 × 0.30 × 0.08 mm

Data collection

Bruker SMART CCD diffractometer	3372 independent reflections
Radiation source: fine-focus sealed tube	2508 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scan	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −15→17
Tmin = 0.614, Tmax = 0.895	k = −4→6
6782 measured reflections	l = −18→26

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)] = 0.069	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.042	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0439P)^2 + 4.0666P] where P = (Fo^2 + 2Fc^2)/3
3372 reflections	(Δ/σ)max = 0.001
244 parameters	Δρmax = 1.15 e Å^−3
0 restraints	Δρmin = −0.91 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
Cd	0.36854 (3)	1.19533 (7)	0.127008 (16)	0.03905 (16)
S1	0.36983 (12)	1.9453 (2)	0.01995 (6)	0.0534 (4)
S2	0.34204 (10)	0.4355 (2)	0.22843 (6)	0.0454 (4)
O11	0.6605 (4)	1.8783 (10)	0.31047 (19)	0.0942 (19)
H11	0.6596	1.8897	0.3470	0.141*
O12	0.5917 (3)	1.5517 (8)	0.33102 (18)	0.0723 (14)
O21	0.0847 (3)	1.8344 (8)	−0.05566 (18)	0.0704 (14)
H21	0.0911	1.8531	−0.0917	0.106*
O22	0.1564 (3)	1.5090 (8)	−0.07626 (17)	0.0666 (13)
N1	0.3709 (4)	1.5019 (8)	0.0663 (2)	0.0517 (13)
N2	0.3834 (4)	0.8721 (8)	0.1845 (2)	0.0491 (12)
N11	0.5311 (3)	1.1962 (8)	0.12753 (18)	0.0444 (11)
H11A	0.5497	1.0759	0.1496	0.053*
H11B	0.5490	1.1700	0.0898	0.053*
N21	0.2090 (3)	1.1290 (8)	0.12274 (19)	0.0434 (11)
H21A	0.1979	1.0110	0.0979	0.052*
H21B	0.1902	1.0882	0.1594	0.052*
C1	0.3708 (3)	1.6850 (9)	0.0478 (2)	0.0346 (11)
C2	0.3665 (3)	0.6914 (10)	0.2019 (2)	0.0352 (12)
C11	0.6269 (4)	1.6892 (12)	0.2951 (2)	0.0490 (15)
C12	0.6268 (4)	1.6347 (10)	0.2301 (2)	0.0416 (13)
C13	0.5841 (3)	1.4385 (10)	0.2097 (2)	0.0416 (13)
H13A	0.5580	1.3378	0.2368	0.050*
C14	0.5802 (3)	1.3925 (9)	0.1488 (2)	0.0362 (12)
C15	0.6206 (4)	1.5416 (10)	0.1095 (2)	0.0461 (14)
H15A	0.6171	1.5127	0.0686	0.055*
C16	0.6659 (4)	1.7321 (10)	0.1298 (2)	0.0466 (14)
H16A	0.6949	1.8276	0.1028	0.056*
C17	0.6687 (4)	1.7830 (10)	0.1904 (2)	0.0433 (13)
H17A	0.6981	1.9138	0.2042	0.052*
C21	0.1189 (4)	1.6441 (11)	−0.0403 (2)	0.0476 (15)
C22	0.1131 (3)	1.5775 (10)	0.0236 (2)	0.0405 (13)
C23	0.1571 (3)	1.3802 (10)	0.0430 (2)	0.0405 (13)
H23A	0.1869	1.2877	0.0156	0.049*
C24	0.1565 (3)	1.3210 (10)	0.1030 (2)	0.0391 (12)
C25	0.1106 (4)	1.4582 (10)	0.1428 (2)	0.0466 (14)
H25A	0.1106	1.4198	0.1832	0.056*
C26	0.0650 (4)	1.6501 (11)	0.1238 (2)	0.0517 (16)
H26A	0.0330	1.7387	0.1509	0.062*
C27	0.0669 (4)	1.7113 (10)	0.0638 (2)	0.0465 (14)
H27A	0.0370	1.8427	0.0508	0.056*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd	0.0572 (3)	0.0253 (2)	0.0346 (2)	0.0008 (2)	−0.00184 (17)	0.00144 (18)
S1	0.1033 (13)	0.0260 (7)	0.0310 (7)	0.0010 (8)	0.0080 (8)	0.0018 (6)
S2	0.0736 (10)	0.0307 (8)	0.0321 (7)	−0.0061 (7)	0.0094 (7)	0.0000 (6)
O11	0.132 (4)	0.111 (4)	0.040 (2)	−0.070 (4)	0.018 (3)	−0.025 (3)
O12	0.106 (4)	0.076 (3)	0.035 (2)	−0.035 (3)	0.010 (2)	−0.006 (2)
O21	0.092 (3)	0.079 (4)	0.041 (2)	0.032 (3)	0.002 (2)	0.015 (2)
O22	0.078 (3)	0.086 (3)	0.036 (2)	0.038 (3)	0.007 (2)	0.010 (2)
N1	0.084 (4)	0.033 (3)	0.038 (3)	−0.001 (3)	0.000 (2)	0.000 (2)
N2	0.080 (4)	0.030 (3)	0.037 (3)	0.004 (2)	0.000 (2)	0.005 (2)
N11	0.062 (3)	0.040 (3)	0.031 (2)	0.005 (2)	0.002 (2)	−0.006 (2)
N21	0.058 (3)	0.039 (3)	0.033 (2)	−0.004 (2)	−0.004 (2)	0.007 (2)
C1	0.045 (3)	0.030 (3)	0.028 (3)	0.002 (3)	0.000 (2)	−0.005 (2)
C2	0.045 (3)	0.035 (3)	0.025 (2)	0.011 (3)	0.000 (2)	−0.005 (2)
C11	0.044 (3)	0.066 (4)	0.037 (3)	−0.014 (3)	0.005 (2)	−0.016 (3)
C12	0.041 (3)	0.052 (4)	0.032 (3)	−0.003 (3)	0.000 (2)	−0.006 (3)
C13	0.041 (3)	0.049 (4)	0.035 (3)	0.002 (3)	0.002 (2)	−0.001 (3)
C14	0.037 (3)	0.040 (3)	0.032 (3)	0.008 (2)	0.002 (2)	−0.007 (2)
C15	0.055 (3)	0.054 (4)	0.030 (3)	0.007 (3)	0.003 (2)	−0.004 (3)
C16	0.052 (3)	0.053 (4)	0.035 (3)	0.005 (3)	0.006 (3)	0.004 (3)
C17	0.045 (3)	0.043 (3)	0.042 (3)	−0.005 (3)	0.001 (2)	−0.008 (3)
C21	0.046 (3)	0.063 (4)	0.033 (3)	0.007 (3)	−0.002 (3)	0.011 (3)
C22	0.037 (3)	0.047 (3)	0.037 (3)	0.000 (3)	−0.006 (2)	0.005 (3)
C23	0.041 (3)	0.050 (3)	0.031 (3)	0.000 (3)	0.001 (2)	0.002 (2)
C24	0.040 (3)	0.043 (3)	0.033 (3)	−0.004 (3)	−0.005 (2)	0.001 (3)
C25	0.055 (3)	0.054 (4)	0.030 (3)	−0.002 (3)	0.001 (2)	0.005 (3)
C26	0.057 (4)	0.065 (4)	0.032 (3)	0.011 (3)	0.004 (3)	−0.002 (3)
C27	0.050 (3)	0.048 (3)	0.041 (3)	0.008 (3)	−0.006 (3)	0.004 (3)

Geometric parameters (Å, º)

Cd—N1	2.250 (5)	N21—H21B	0.900
Cd—N2	2.297 (5)	C11—C12	1.487 (7)
Cd—N21	2.374 (4)	C12—C13	1.383 (7)
Cd—N11	2.386 (4)	C12—C17	1.390 (8)
Cd—S2^i	2.700 (1)	C13—C14	1.388 (7)
Cd—S1^ii	2.805 (1)	C13—H13A	0.930
S1—C1	1.646 (6)	C14—C15	1.378 (7)
S1—Cd^i	2.8053 (14)	C15—C16	1.373 (8)
S2—C2	1.652 (6)	C15—H15A	0.930
S2—Cd^ii	2.7000 (14)	C16—C17	1.386 (7)
O11—C11	1.258 (7)	C16—H16A	0.930
O11—H11	0.820	C17—H17A	0.930
O12—C11	1.253 (7)	C21—C22	1.484 (7)
O21—C21	1.268 (7)	C22—C27	1.378 (8)
O21—H21	0.820	C22—C23	1.390 (7)
O22—C21	1.259 (7)	C23—C24	1.385 (7)
N1—C1	1.149 (6)	C23—H23A	0.930
N2—C2	1.155 (6)	C24—C25	1.381 (7)
N11—C14	1.434 (7)	C25—C26	1.373 (8)
N11—H11A	0.900	C25—H25A	0.930
N11—H11B	0.900	C26—C27	1.388 (7)
N21—C24	1.429 (7)	C26—H26A	0.930
N21—H21A	0.900	C27—H27A	0.930
N1—Cd—N2	173.02 (18)	C13—C12—C11	119.6 (5)
N1—Cd—N21	97.39 (17)	C17—C12—C11	119.7 (5)
N2—Cd—N21	88.53 (16)	C12—C13—C14	119.8 (5)
N1—Cd—N11	88.77 (17)	C12—C13—H13A	120.1
N2—Cd—N11	84.90 (17)	C14—C13—H13A	120.1
N21—Cd—N11	170.49 (16)	C15—C14—C13	119.4 (5)
N1—Cd—S2^i	95.41 (12)	C15—C14—N11	120.9 (5)
N2—Cd—S2^i	88.45 (12)	C13—C14—N11	119.7 (5)
N21—Cd—S2^i	88.07 (11)	C16—C15—C14	120.9 (5)
N11—Cd—S2^i	98.60 (10)	C16—C15—H15A	119.5
N1—Cd—S1^ii	84.35 (12)	C14—C15—H15A	119.5
N2—Cd—S1^ii	92.63 (12)	C15—C16—C17	120.4 (5)
N21—Cd—S1^ii	84.13 (11)	C15—C16—H16A	119.8
N11—Cd—S1^ii	89.29 (10)	C17—C16—H16A	119.8
S2^i—Cd—S1^ii	172.10 (5)	C16—C17—C12	118.8 (5)
C1—S1—Cd^i	99.24 (17)	C16—C17—H17A	120.6
C2—S2—Cd^ii	97.84 (17)	C12—C17—H17A	120.6
C11—O11—H11	109.5	O22—C21—O21	123.7 (5)
C21—O21—H21	109.5	O22—C21—C22	118.7 (5)
C1—N1—Cd	164.0 (4)	O21—C21—C22	117.6 (5)
C2—N2—Cd	157.4 (4)	C27—C22—C23	119.9 (5)
C14—N11—Cd	120.0 (3)	C27—C22—C21	120.9 (5)
C14—N11—H11A	107.3	C23—C22—C21	119.1 (5)
Cd—N11—H11A	107.3	C24—C23—C22	120.1 (5)
C14—N11—H11B	107.3	C24—C23—H23A	119.9
Cd—N11—H11B	107.3	C22—C23—H23A	119.9
H11A—N11—H11B	106.9	C25—C24—C23	119.2 (5)
C24—N21—Cd	114.2 (3)	C25—C24—N21	121.5 (5)
C24—N21—H21A	108.7	C23—C24—N21	119.1 (5)
Cd—N21—H21A	108.7	C26—C25—C24	121.0 (5)
C24—N21—H21B	108.7	C26—C25—H25A	119.5
Cd—N21—H21B	108.7	C24—C25—H25A	119.5
H21A—N21—H21B	107.6	C25—C26—C27	119.7 (5)
N1—C1—S1	178.8 (5)	C25—C26—H26A	120.2
N2—C2—S2	178.6 (5)	C27—C26—H26A	120.2
O12—C11—O11	123.6 (5)	C22—C27—C26	120.0 (5)
O12—C11—C12	119.6 (5)	C22—C27—H27A	120.0
O11—C11—C12	116.8 (6)	C26—C27—H27A	120.0
C13—C12—C17	120.7 (5)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11···O22^iii	0.82	1.82	2.618 (6)	166
O21—H21···O12^iv	0.82	1.81	2.622 (5)	169

Symmetry codes: (iii) x+1/2, −y+7/2, z+1/2; (iv) x−1/2, −y+7/2, z−1/2.