The title compound, {[Cd4(C5H2N2O4)(C5HN2O4)2(C10H8N2)2(H2O)]·2H2O}n, crystallized in the monoclinic space group P21/n and displays a three-dimensional architecture. The asymmetric unit is composed of four crystallographically independent CdII centres, two triply deprotonated pyrazole-3,5-dicarboxylic acid molecules, one doubly deprotonated pyrazole-3,5-dicarboxylic acid molecule, two 2,2′-bipyridine ligands, one coordinated water molecule and two interstitial water molecules. Interestingly, the CdII centers exhibit two different coordination numbers. Two CdII centres adopt a distorted octahedral arrangement and a third a trigonal–prismatic geometry, though they are all hexacoordinated. However, the fourth CdII center is heptacoordinated and displays a pentagonal–bipyramidal geometry. The three anionic ligands adopt μ3-, μ4- and μ5-bridging modes, first linking CdII centers into a one-dimensional wave-like band, then into a wave-like layer and finally into a three-dimensional coordination framework, which is stabilized by hydrogen bonds.
Supporting information
CCDC reference: 873881
Cd(NO3)2.4H2O (0.154 g, 0.5 mmol), pyrazole-3,5-dicarboxylic acid (0.156 g, 1.0 mmol) and 2,2'-bipyridine (0.156 g, 1.0 mmol) were mixed with deionized
water (8 ml) in a 25 ml Parr Teflon-lined stainless steel vessel. The vessel
was sealed and heated to 433 K. The temperature was maintained for 3 d and
then the mixture was allowed to cool naturally to obtain colorless crystals of
(I) [yield 42%, based on Cd(NO3)2.4H2O]. Elemental analysis calculated
for C35H26Cd4N10O15: C 32.93, H 2.05, N 10.97%; found: C 33.34, H
1.96, N 11.13%. IR (KBr pellet, ν cm-1): 3424, 3140, 1623, 1555, 1508,
1439, 1365, 1018, 846, 762, 651, 579.
H atoms bonded to C atoms were placed in calculated positions and treated using
a riding model approximation, with C—H = 0.96 Å and Uiso(H) =
1.2Ueq(C). Initially, the aqua H atoms were located in a difference
Fourier map and their positions were adjusted, using the HIMP command in
XP (SHELXTL; Bruker, 2000), to O—H = 0.85 Å. In the final
cycles, these H atoms were constrained to ride on their parent O atoms, with
Uiso(H) = 1.5Ueq(O).
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP IN SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
poly[[aquabis(2,2'-bipyridine)(µ
5-pyrazol-1-ide-3,5-dicarboxylato)(µ
4-
pyrazol-1-ide-3,5-dicarboxylato)(µ
3-pyrazole-3,5-
dicarboxylato)tetracadmium(II)] dihydrate]
top
Crystal data top
[Cd4(C5H2N2O4)(C5HN2O4)2(C10H8N2)2(H2O)]·2H2O | F(000) = 2472 |
Mr = 1276.26 | Dx = 2.102 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P2yn | Cell parameters from 49694 reflections |
a = 15.574 (3) Å | θ = 1.3–27.5° |
b = 16.197 (3) Å | µ = 2.17 mm−1 |
c = 16.928 (3) Å | T = 293 K |
β = 109.21 (3)° | Block, yellow |
V = 4032.3 (14) Å3 | 0.16 × 0.13 × 0.13 mm |
Z = 4 | |
Data collection top
Bruker APEXII CCD area-detector diffractometer | 9211 independent reflections |
Radiation source: fine-focus sealed tube | 8760 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
ϕ and ω scans | θmax = 27.5°, θmin = 1.5° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = 0→20 |
Tmin = 0.72, Tmax = 0.76 | k = 0→21 |
38399 measured reflections | l = −21→20 |
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)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0759P)2 + 6.8969P] where P = (Fo2 + 2Fc2)/3 |
9211 reflections | (Δ/σ)max = 0.002 |
578 parameters | Δρmax = 1.99 e Å−3 |
656 restraints | Δρmin = −1.24 e Å−3 |
Crystal data top
[Cd4(C5H2N2O4)(C5HN2O4)2(C10H8N2)2(H2O)]·2H2O | V = 4032.3 (14) Å3 |
Mr = 1276.26 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 15.574 (3) Å | µ = 2.17 mm−1 |
b = 16.197 (3) Å | T = 293 K |
c = 16.928 (3) Å | 0.16 × 0.13 × 0.13 mm |
β = 109.21 (3)° | |
Data collection top
Bruker APEXII CCD area-detector diffractometer | 9211 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 8760 reflections with I > 2σ(I) |
Tmin = 0.72, Tmax = 0.76 | Rint = 0.033 |
38399 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.030 | 656 restraints |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 1.08 | Δρmax = 1.99 e Å−3 |
9211 reflections | Δρmin = −1.24 e Å−3 |
578 parameters | |
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. |
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Cd1 | 0.70024 (2) | 0.676520 (18) | 0.505581 (19) | 0.02253 (9) | |
Cd2 | 0.814615 (18) | 0.893103 (16) | 0.274573 (16) | 0.01671 (8) | |
Cd3 | 0.725505 (19) | 1.128017 (16) | 0.256542 (18) | 0.01986 (9) | |
Cd4 | 1.04689 (2) | 0.746181 (17) | 0.23133 (2) | 0.02443 (9) | |
N1 | 0.6734 (2) | 1.0167 (2) | 0.3063 (2) | 0.0198 (6) | |
N2 | 0.7095 (2) | 0.9416 (2) | 0.3294 (2) | 0.0192 (6) | |
N3 | 0.9234 (3) | 1.1104 (2) | 0.4372 (2) | 0.0275 (8) | |
H3A | 0.9321 | 1.0580 | 0.4370 | 0.033* | |
N4 | 0.8604 (2) | 1.1513 (2) | 0.3767 (2) | 0.0252 (7) | |
N5 | 0.9052 (2) | 0.9069 (2) | 0.1913 (2) | 0.0199 (6) | |
N6 | 0.9643 (2) | 0.8572 (2) | 0.1723 (2) | 0.0210 (6) | |
N7 | 0.8107 (3) | 0.7382 (3) | 0.6186 (3) | 0.0374 (9) | |
N8 | 0.8290 (3) | 0.5933 (3) | 0.5474 (2) | 0.0311 (8) | |
N9 | 1.1690 (3) | 0.6725 (3) | 0.3202 (3) | 0.0438 (11) | |
N10 | 1.1351 (3) | 0.8339 (3) | 0.3380 (3) | 0.0384 (9) | |
O1 | 0.4898 (3) | 1.1192 (2) | 0.3466 (3) | 0.0381 (8) | |
O2 | 0.5762 (2) | 1.15871 (19) | 0.2730 (2) | 0.0308 (7) | |
O3 | 0.7583 (2) | 0.7894 (2) | 0.4154 (2) | 0.0359 (7) | |
O4 | 0.6296 (3) | 0.7898 (2) | 0.4440 (2) | 0.0352 (7) | |
O5 | 0.8185 (2) | 1.36687 (19) | 0.3612 (2) | 0.0347 (8) | |
O6 | 0.7483 (2) | 1.26534 (18) | 0.27902 (19) | 0.0268 (6) | |
O7 | 1.0683 (2) | 1.0599 (2) | 0.5824 (2) | 0.0364 (8) | |
O8 | 1.0682 (2) | 1.18431 (19) | 0.6353 (2) | 0.0289 (6) | |
O9 | 0.8074 (2) | 1.03199 (18) | 0.2196 (2) | 0.0260 (6) | |
O10 | 0.8393 (2) | 1.11416 (19) | 0.1277 (2) | 0.0283 (6) | |
O11 | 1.1039 (2) | 0.7896 (2) | 0.1270 (2) | 0.0311 (7) | |
O12 | 1.0987 (3) | 0.8952 (2) | 0.0419 (2) | 0.0337 (7) | |
O1W | 0.6411 (2) | 1.16531 (19) | 0.12419 (19) | 0.0260 (6) | |
H1A | 0.6180 | 1.2100 | 0.1344 | 0.039* | |
H1B | 0.6762 | 1.1849 | 0.0995 | 0.039* | |
C1 | 0.6030 (3) | 1.0268 (2) | 0.3354 (2) | 0.0213 (7) | |
C2 | 0.5914 (3) | 0.9565 (2) | 0.3776 (3) | 0.0237 (7) | |
H2A | 0.5480 | 0.9466 | 0.4033 | 0.028* | |
C3 | 0.6603 (3) | 0.9042 (2) | 0.3723 (2) | 0.0201 (7) | |
C4 | 0.5531 (3) | 1.1058 (2) | 0.3179 (3) | 0.0241 (8) | |
C5 | 0.6859 (3) | 0.8219 (2) | 0.4123 (3) | 0.0230 (8) | |
C6 | 0.8703 (3) | 1.2310 (2) | 0.3999 (3) | 0.0240 (8) | |
C7 | 0.9391 (3) | 1.2398 (3) | 0.4764 (3) | 0.0279 (9) | |
H7A | 0.9590 | 1.2884 | 0.5061 | 0.034* | |
C8 | 0.9715 (3) | 1.1616 (3) | 0.4986 (3) | 0.0266 (8) | |
C9 | 0.8094 (3) | 1.2929 (3) | 0.3443 (2) | 0.0229 (7) | |
C10 | 1.0414 (3) | 1.1318 (3) | 0.5769 (3) | 0.0250 (8) | |
C11 | 0.9058 (3) | 0.9807 (2) | 0.1535 (2) | 0.0199 (7) | |
C12 | 0.9671 (3) | 0.9788 (3) | 0.1091 (3) | 0.0237 (7) | |
H12B | 0.9807 | 1.0207 | 0.0776 | 0.028* | |
C13 | 1.0029 (3) | 0.8997 (3) | 0.1233 (3) | 0.0225 (7) | |
C14 | 0.8472 (3) | 1.0474 (2) | 0.1663 (2) | 0.0195 (7) | |
C15 | 1.0737 (3) | 0.8583 (3) | 0.0959 (3) | 0.0220 (7) | |
C16 | 0.8900 (4) | 0.6989 (4) | 0.6507 (3) | 0.0392 (10) | |
C17 | 0.9599 (5) | 0.7324 (5) | 0.7163 (5) | 0.0591 (15) | |
H17A | 1.0153 | 0.7052 | 0.7375 | 0.071* | |
C18 | 0.9458 (6) | 0.8076 (5) | 0.7500 (5) | 0.0690 (17) | |
H18A | 0.9906 | 0.8300 | 0.7959 | 0.083* | |
C19 | 0.8657 (6) | 0.8476 (5) | 0.7150 (5) | 0.0642 (16) | |
H19A | 0.8560 | 0.8992 | 0.7348 | 0.077* | |
C20 | 0.7987 (5) | 0.8108 (4) | 0.6495 (4) | 0.0538 (14) | |
H20A | 0.7434 | 0.8378 | 0.6265 | 0.065* | |
C21 | 0.8992 (4) | 0.6177 (3) | 0.6129 (3) | 0.0345 (9) | |
C22 | 0.9771 (4) | 0.5694 (4) | 0.6432 (4) | 0.0472 (12) | |
H22A | 1.0258 | 0.5874 | 0.6885 | 0.057* | |
C23 | 0.9816 (4) | 0.4953 (4) | 0.6060 (4) | 0.0522 (13) | |
H23A | 1.0328 | 0.4619 | 0.6265 | 0.063* | |
C24 | 0.9106 (5) | 0.4709 (4) | 0.5388 (4) | 0.0505 (13) | |
H24A | 0.9127 | 0.4211 | 0.5120 | 0.061* | |
C25 | 0.8355 (4) | 0.5214 (3) | 0.5110 (3) | 0.0427 (11) | |
H25A | 0.7870 | 0.5046 | 0.4649 | 0.051* | |
C26 | 1.2278 (4) | 0.7132 (5) | 0.3841 (4) | 0.0492 (12) | |
C27 | 1.3070 (5) | 0.6744 (6) | 0.4337 (5) | 0.0686 (17) | |
H27A | 1.3488 | 0.7027 | 0.4774 | 0.082* | |
C28 | 1.3227 (6) | 0.5925 (6) | 0.4169 (5) | 0.0710 (17) | |
H28A | 1.3749 | 0.5657 | 0.4502 | 0.085* | |
C29 | 1.2631 (5) | 0.5523 (5) | 0.3531 (5) | 0.0665 (17) | |
H29A | 1.2731 | 0.4977 | 0.3414 | 0.080* | |
C30 | 1.1860 (5) | 0.5941 (5) | 0.3050 (5) | 0.0587 (15) | |
H30A | 1.1445 | 0.5667 | 0.2604 | 0.070* | |
C31 | 1.2058 (4) | 0.7994 (4) | 0.3978 (4) | 0.0463 (11) | |
C32 | 1.2540 (5) | 0.8443 (5) | 0.4676 (4) | 0.0613 (15) | |
H32A | 1.3022 | 0.8200 | 0.5091 | 0.074* | |
C33 | 1.2304 (5) | 0.9254 (5) | 0.4758 (4) | 0.0643 (16) | |
H33A | 1.2618 | 0.9558 | 0.5231 | 0.077* | |
C34 | 1.1595 (5) | 0.9606 (5) | 0.4126 (4) | 0.0577 (15) | |
H34A | 1.1436 | 1.0155 | 0.4157 | 0.069* | |
C35 | 1.1131 (4) | 0.9128 (4) | 0.3455 (4) | 0.0457 (11) | |
H35A | 1.0645 | 0.9359 | 0.3035 | 0.055* | |
O2W | 0.4685 (4) | 0.8415 (5) | 0.4745 (4) | 0.0890 (18) | |
H2C | 0.5156 | 0.8208 | 0.4675 | 0.134* | |
H2D | 0.4802 | 0.8542 | 0.5256 | 0.134* | |
O3W | 0.3652 (7) | 0.9955 (8) | 0.3855 (7) | 0.156 (3) | |
H3E | 0.3998 | 1.0299 | 0.3729 | 0.233* | |
H3F | 0.3934 | 0.9522 | 0.4087 | 0.233* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cd1 | 0.02292 (16) | 0.01840 (15) | 0.02728 (16) | 0.00061 (10) | 0.00963 (12) | 0.00386 (10) |
Cd2 | 0.01610 (14) | 0.01419 (14) | 0.01820 (14) | 0.00095 (9) | 0.00344 (10) | −0.00106 (9) |
Cd3 | 0.02066 (15) | 0.01355 (14) | 0.02426 (15) | 0.00125 (9) | 0.00589 (11) | 0.00066 (9) |
Cd4 | 0.02177 (16) | 0.01626 (15) | 0.03130 (17) | −0.00147 (10) | 0.00336 (12) | 0.00397 (10) |
N1 | 0.0197 (15) | 0.0154 (15) | 0.0241 (15) | 0.0023 (12) | 0.0071 (12) | 0.0018 (12) |
N2 | 0.0207 (15) | 0.0141 (14) | 0.0229 (15) | 0.0016 (12) | 0.0074 (12) | 0.0012 (12) |
N3 | 0.0277 (18) | 0.0150 (15) | 0.0282 (18) | 0.0044 (13) | −0.0067 (15) | 0.0016 (13) |
N4 | 0.0252 (17) | 0.0193 (16) | 0.0228 (16) | 0.0040 (13) | −0.0035 (13) | 0.0014 (13) |
N5 | 0.0204 (15) | 0.0171 (15) | 0.0233 (16) | 0.0031 (12) | 0.0084 (13) | 0.0020 (12) |
N6 | 0.0218 (16) | 0.0188 (15) | 0.0231 (16) | 0.0040 (12) | 0.0084 (13) | 0.0018 (12) |
N7 | 0.037 (2) | 0.033 (2) | 0.040 (2) | −0.0039 (17) | 0.0106 (18) | −0.0067 (17) |
N8 | 0.0303 (19) | 0.031 (2) | 0.0285 (18) | 0.0091 (16) | 0.0046 (15) | 0.0035 (15) |
N9 | 0.028 (2) | 0.046 (3) | 0.052 (3) | 0.0081 (18) | 0.0060 (19) | 0.020 (2) |
N10 | 0.027 (2) | 0.049 (3) | 0.032 (2) | −0.0061 (18) | −0.0001 (16) | −0.0063 (18) |
O1 | 0.0393 (19) | 0.0290 (16) | 0.056 (2) | 0.0128 (14) | 0.0293 (17) | 0.0093 (15) |
O2 | 0.0334 (16) | 0.0200 (14) | 0.0431 (18) | 0.0089 (12) | 0.0182 (14) | 0.0096 (13) |
O3 | 0.0353 (18) | 0.0220 (15) | 0.052 (2) | 0.0087 (13) | 0.0172 (15) | 0.0015 (14) |
O4 | 0.0417 (18) | 0.0255 (16) | 0.0452 (18) | 0.0056 (14) | 0.0236 (15) | 0.0123 (14) |
O5 | 0.0345 (18) | 0.0182 (15) | 0.0384 (18) | 0.0018 (12) | −0.0059 (14) | 0.0003 (12) |
O6 | 0.0284 (15) | 0.0175 (13) | 0.0256 (14) | 0.0030 (11) | −0.0033 (12) | 0.0013 (11) |
O7 | 0.0342 (17) | 0.0206 (15) | 0.0402 (18) | 0.0046 (13) | −0.0068 (14) | 0.0038 (13) |
O8 | 0.0275 (15) | 0.0236 (15) | 0.0264 (15) | −0.0028 (12) | −0.0035 (12) | 0.0026 (11) |
O9 | 0.0332 (15) | 0.0178 (13) | 0.0332 (15) | 0.0056 (11) | 0.0194 (13) | 0.0029 (11) |
O10 | 0.0385 (17) | 0.0188 (14) | 0.0296 (15) | 0.0070 (12) | 0.0141 (13) | 0.0062 (11) |
O11 | 0.0341 (16) | 0.0244 (15) | 0.0401 (17) | 0.0092 (12) | 0.0194 (14) | 0.0045 (13) |
O12 | 0.0428 (19) | 0.0305 (17) | 0.0376 (18) | 0.0109 (14) | 0.0267 (15) | 0.0082 (13) |
O1W | 0.0303 (15) | 0.0223 (14) | 0.0254 (14) | −0.0001 (12) | 0.0093 (12) | 0.0019 (11) |
C1 | 0.0223 (17) | 0.0192 (17) | 0.0231 (17) | 0.0034 (14) | 0.0087 (14) | 0.0007 (14) |
C2 | 0.0257 (18) | 0.0184 (17) | 0.0297 (18) | 0.0021 (14) | 0.0125 (15) | 0.0040 (14) |
C3 | 0.0220 (17) | 0.0166 (16) | 0.0222 (17) | −0.0004 (14) | 0.0078 (14) | 0.0001 (13) |
C4 | 0.0244 (19) | 0.0185 (18) | 0.0284 (19) | 0.0028 (14) | 0.0072 (15) | −0.0007 (14) |
C5 | 0.0277 (19) | 0.0150 (17) | 0.0256 (18) | 0.0012 (14) | 0.0079 (15) | −0.0006 (13) |
C6 | 0.0246 (18) | 0.0163 (16) | 0.0245 (17) | 0.0028 (14) | −0.0009 (15) | 0.0025 (14) |
C7 | 0.032 (2) | 0.0163 (17) | 0.0259 (19) | 0.0035 (15) | −0.0034 (16) | −0.0012 (14) |
C8 | 0.0264 (19) | 0.0200 (18) | 0.0243 (18) | 0.0026 (15) | −0.0041 (15) | 0.0007 (15) |
C9 | 0.0204 (17) | 0.0211 (18) | 0.0219 (17) | 0.0032 (14) | 0.0001 (14) | 0.0050 (14) |
C10 | 0.0205 (18) | 0.0202 (18) | 0.0262 (19) | −0.0026 (14) | −0.0033 (15) | 0.0040 (14) |
C11 | 0.0227 (17) | 0.0173 (16) | 0.0202 (16) | 0.0015 (13) | 0.0079 (13) | 0.0011 (13) |
C12 | 0.0271 (18) | 0.0205 (18) | 0.0265 (18) | 0.0040 (15) | 0.0130 (15) | 0.0025 (14) |
C13 | 0.0223 (17) | 0.0232 (18) | 0.0223 (17) | 0.0037 (14) | 0.0078 (14) | 0.0014 (14) |
C14 | 0.0198 (16) | 0.0181 (16) | 0.0201 (16) | 0.0017 (13) | 0.0057 (13) | −0.0013 (13) |
C15 | 0.0222 (17) | 0.0216 (18) | 0.0242 (18) | 0.0033 (14) | 0.0101 (14) | −0.0028 (14) |
C16 | 0.034 (2) | 0.045 (2) | 0.038 (2) | −0.0056 (19) | 0.0103 (18) | −0.0043 (19) |
C17 | 0.048 (3) | 0.060 (3) | 0.058 (3) | −0.006 (3) | 0.002 (2) | −0.012 (3) |
C18 | 0.065 (3) | 0.065 (3) | 0.062 (3) | −0.014 (3) | 0.000 (3) | −0.023 (3) |
C19 | 0.069 (4) | 0.056 (3) | 0.061 (3) | −0.010 (3) | 0.014 (3) | −0.027 (3) |
C20 | 0.054 (3) | 0.046 (3) | 0.058 (3) | −0.002 (2) | 0.014 (3) | −0.020 (2) |
C21 | 0.032 (2) | 0.040 (2) | 0.031 (2) | 0.0017 (18) | 0.0099 (17) | 0.0051 (17) |
C22 | 0.036 (2) | 0.056 (3) | 0.042 (2) | 0.009 (2) | 0.003 (2) | 0.005 (2) |
C23 | 0.047 (3) | 0.057 (3) | 0.047 (3) | 0.024 (2) | 0.008 (2) | 0.007 (2) |
C24 | 0.060 (3) | 0.042 (3) | 0.047 (3) | 0.022 (2) | 0.015 (2) | 0.002 (2) |
C25 | 0.047 (3) | 0.037 (2) | 0.037 (2) | 0.012 (2) | 0.004 (2) | −0.0012 (19) |
C26 | 0.034 (2) | 0.069 (3) | 0.040 (2) | 0.006 (2) | 0.0070 (19) | 0.012 (2) |
C27 | 0.050 (3) | 0.089 (4) | 0.053 (3) | 0.017 (3) | −0.002 (3) | 0.011 (3) |
C28 | 0.057 (3) | 0.083 (4) | 0.062 (3) | 0.023 (3) | 0.005 (3) | 0.023 (3) |
C29 | 0.056 (3) | 0.068 (3) | 0.071 (3) | 0.023 (3) | 0.016 (3) | 0.025 (3) |
C30 | 0.048 (3) | 0.058 (3) | 0.064 (3) | 0.014 (3) | 0.010 (3) | 0.022 (3) |
C31 | 0.030 (2) | 0.070 (3) | 0.036 (2) | −0.003 (2) | 0.0070 (18) | 0.004 (2) |
C32 | 0.042 (3) | 0.085 (4) | 0.043 (3) | −0.006 (3) | −0.004 (2) | −0.002 (3) |
C33 | 0.052 (3) | 0.082 (4) | 0.048 (3) | −0.019 (3) | 0.001 (2) | −0.015 (3) |
C34 | 0.051 (3) | 0.067 (4) | 0.050 (3) | −0.016 (3) | 0.010 (2) | −0.017 (3) |
C35 | 0.038 (2) | 0.055 (3) | 0.040 (2) | −0.007 (2) | 0.0064 (19) | −0.009 (2) |
O2W | 0.062 (3) | 0.132 (5) | 0.085 (4) | 0.016 (3) | 0.040 (3) | 0.023 (4) |
O3W | 0.122 (5) | 0.179 (6) | 0.161 (6) | −0.002 (5) | 0.040 (5) | 0.031 (5) |
Geometric parameters (Å, º) top
Cd1—O3 | 2.719 (4) | O10—Cd1iv | 2.362 (3) |
Cd1—O4 | 2.216 (3) | O11—C15 | 1.255 (5) |
Cd1—O10i | 2.362 (3) | O12—C15 | 1.256 (5) |
Cd1—O12ii | 2.206 (3) | O12—Cd1v | 2.206 (3) |
Cd1—N7 | 2.335 (4) | O1W—H1A | 0.8516 |
Cd1—N8 | 2.324 (4) | O1W—H1B | 0.8507 |
Cd2—O5i | 2.575 (3) | C1—C2 | 1.387 (5) |
Cd2—O6i | 2.341 (3) | C1—C4 | 1.475 (5) |
Cd2—O7iii | 2.619 (3) | C2—C3 | 1.392 (6) |
Cd2—O8iii | 2.324 (3) | C2—H2A | 0.9300 |
Cd2—O9 | 2.423 (3) | C3—C5 | 1.488 (5) |
Cd2—N2 | 2.271 (3) | C4—Cd4iv | 2.727 (4) |
Cd2—N5 | 2.310 (3) | C6—C7 | 1.390 (6) |
Cd3—O1W | 2.275 (3) | C6—C9 | 1.484 (5) |
Cd3—O2 | 2.482 (3) | C7—C8 | 1.369 (6) |
Cd3—O6 | 2.265 (3) | C7—H7A | 0.9300 |
Cd3—O9 | 2.227 (3) | C8—C10 | 1.492 (5) |
Cd3—N1 | 2.251 (3) | C11—C12 | 1.395 (5) |
Cd3—N4 | 2.425 (4) | C11—C14 | 1.476 (5) |
Cd4—O1i | 2.408 (4) | C12—C13 | 1.387 (6) |
Cd4—O2i | 2.365 (3) | C12—H12B | 0.9300 |
Cd4—O11 | 2.332 (3) | C13—C15 | 1.488 (5) |
Cd4—N6 | 2.245 (3) | C16—C17 | 1.385 (8) |
Cd4—N9 | 2.329 (4) | C16—C21 | 1.491 (8) |
Cd4—N10 | 2.353 (4) | C17—C18 | 1.392 (11) |
Cd4—C4i | 2.727 (4) | C17—H17A | 0.9300 |
N1—N2 | 1.342 (4) | C18—C19 | 1.357 (12) |
N1—C1 | 1.352 (5) | C18—H18A | 0.9300 |
N2—C3 | 1.359 (5) | C19—C20 | 1.383 (9) |
N3—N4 | 1.339 (5) | C19—H19A | 0.9300 |
N3—C8 | 1.348 (5) | C20—H20A | 0.9300 |
N3—H3A | 0.8600 | C21—C22 | 1.392 (7) |
N4—C6 | 1.343 (5) | C22—C23 | 1.369 (9) |
N5—N6 | 1.339 (5) | C22—H22A | 0.9300 |
N5—C11 | 1.357 (5) | C23—C24 | 1.359 (9) |
N6—C13 | 1.361 (5) | C23—H23A | 0.9300 |
N7—C20 | 1.326 (7) | C24—C25 | 1.378 (8) |
N7—C16 | 1.335 (7) | C24—H24A | 0.9300 |
N8—C21 | 1.336 (7) | C25—H25A | 0.9300 |
N8—C25 | 1.337 (7) | C26—C27 | 1.392 (9) |
N9—C26 | 1.338 (8) | C26—C31 | 1.475 (10) |
N9—C30 | 1.339 (9) | C27—C28 | 1.395 (12) |
N10—C35 | 1.339 (8) | C27—H27A | 0.9300 |
N10—C31 | 1.347 (7) | C28—C29 | 1.339 (12) |
O1—C4 | 1.253 (5) | C28—H28A | 0.9300 |
O1—Cd4iv | 2.408 (4) | C29—C30 | 1.385 (9) |
O2—C4 | 1.273 (5) | C29—H29A | 0.9300 |
O2—Cd4iv | 2.365 (3) | C30—H30A | 0.9300 |
O3—C5 | 1.229 (5) | C31—C32 | 1.380 (9) |
O4—C5 | 1.280 (5) | C32—C33 | 1.383 (12) |
O5—C9 | 1.228 (5) | C32—H32A | 0.9300 |
O5—Cd2iv | 2.575 (3) | C33—C34 | 1.383 (11) |
O6—C9 | 1.279 (5) | C33—H33A | 0.9300 |
O6—Cd2iv | 2.341 (3) | C34—C35 | 1.369 (8) |
O7—C10 | 1.231 (5) | C34—H34A | 0.9300 |
O7—Cd2iii | 2.619 (3) | C35—H35A | 0.9300 |
O8—C10 | 1.266 (5) | O2W—H2C | 0.8501 |
O8—Cd2iii | 2.324 (3) | O2W—H2D | 0.8490 |
O9—C14 | 1.276 (5) | O3W—H3E | 0.8506 |
O10—C14 | 1.249 (5) | O3W—H3F | 0.8509 |
| | | |
O12ii—Cd1—O4 | 106.07 (14) | C14—O10—Cd1iv | 145.1 (3) |
O12ii—Cd1—N8 | 103.62 (15) | C15—O11—Cd4 | 113.6 (3) |
O4—Cd1—N8 | 150.26 (14) | C15—O12—Cd1v | 112.0 (3) |
O12ii—Cd1—N7 | 113.52 (15) | Cd3—O1W—H1A | 99.9 |
O4—Cd1—N7 | 98.58 (16) | Cd3—O1W—H1B | 109.1 |
N8—Cd1—N7 | 70.70 (16) | H1A—O1W—H1B | 99.5 |
O12ii—Cd1—O10i | 93.20 (12) | N1—C1—C2 | 110.3 (3) |
O4—Cd1—O10i | 88.37 (13) | N1—C1—C4 | 117.9 (4) |
N8—Cd1—O10i | 88.31 (13) | C2—C1—C4 | 131.8 (4) |
N7—Cd1—O10i | 148.88 (14) | C1—C2—C3 | 103.5 (3) |
O12ii—Cd1—O3 | 155.69 (13) | C1—C2—H2A | 128.3 |
O4—Cd1—O3 | 52.01 (11) | C3—C2—H2A | 128.3 |
N8—Cd1—O3 | 98.51 (13) | N2—C3—C2 | 110.1 (3) |
N7—Cd1—O3 | 83.17 (14) | N2—C3—C5 | 121.9 (4) |
O10i—Cd1—O3 | 77.38 (11) | C2—C3—C5 | 127.8 (4) |
N2—Cd2—N5 | 151.99 (12) | O1—C4—O2 | 121.8 (4) |
N2—Cd2—O8iii | 115.78 (12) | O1—C4—C1 | 120.2 (4) |
N5—Cd2—O8iii | 86.98 (12) | O2—C4—C1 | 118.1 (4) |
N2—Cd2—O6i | 101.41 (12) | O1—C4—Cd4iv | 62.0 (2) |
N5—Cd2—O6i | 96.36 (12) | O2—C4—Cd4iv | 60.1 (2) |
O8iii—Cd2—O6i | 85.17 (11) | C1—C4—Cd4iv | 174.0 (3) |
N2—Cd2—O9 | 83.50 (10) | O3—C5—O4 | 123.5 (4) |
N5—Cd2—O9 | 68.68 (11) | O3—C5—C3 | 120.6 (4) |
O8iii—Cd2—O9 | 132.87 (11) | O4—C5—C3 | 115.8 (4) |
O6i—Cd2—O9 | 135.34 (11) | N4—C6—C7 | 110.5 (3) |
N2—Cd2—O5i | 86.82 (12) | N4—C6—C9 | 118.4 (4) |
N5—Cd2—O5i | 86.86 (13) | C7—C6—C9 | 131.0 (4) |
O8iii—Cd2—O5i | 136.48 (11) | C8—C7—C6 | 105.2 (4) |
O6i—Cd2—O5i | 52.88 (10) | C8—C7—H7A | 127.4 |
O9—Cd2—O5i | 83.60 (11) | C6—C7—H7A | 127.4 |
N2—Cd2—O7iii | 84.16 (12) | N3—C8—C7 | 107.3 (4) |
N5—Cd2—O7iii | 99.02 (13) | N3—C8—C10 | 123.0 (4) |
O8iii—Cd2—O7iii | 52.59 (11) | C7—C8—C10 | 129.6 (4) |
O6i—Cd2—O7iii | 133.68 (10) | O5—C9—O6 | 122.5 (4) |
O9—Cd2—O7iii | 90.86 (11) | O5—C9—C6 | 120.7 (4) |
O5i—Cd2—O7iii | 169.90 (11) | O6—C9—C6 | 116.7 (4) |
O9—Cd3—N1 | 81.70 (12) | O7—C10—O8 | 124.0 (4) |
O9—Cd3—O6 | 131.32 (12) | O7—C10—C8 | 120.3 (4) |
N1—Cd3—O6 | 141.23 (12) | O8—C10—C8 | 115.7 (4) |
O9—Cd3—O1W | 96.18 (12) | N5—C11—C12 | 110.3 (3) |
N1—Cd3—O1W | 114.75 (12) | N5—C11—C14 | 118.3 (3) |
O6—Cd3—O1W | 84.99 (11) | C12—C11—C14 | 131.4 (4) |
O9—Cd3—N4 | 85.77 (12) | C13—C12—C11 | 103.6 (4) |
N1—Cd3—N4 | 97.48 (12) | C13—C12—H12B | 128.2 |
O6—Cd3—N4 | 70.21 (11) | C11—C12—H12B | 128.2 |
O1W—Cd3—N4 | 147.68 (12) | N6—C13—C12 | 109.8 (4) |
O9—Cd3—O2 | 144.65 (12) | N6—C13—C15 | 119.0 (4) |
N1—Cd3—O2 | 69.64 (11) | C12—C13—C15 | 131.2 (4) |
O6—Cd3—O2 | 83.42 (11) | O10—C14—O9 | 123.5 (4) |
O1W—Cd3—O2 | 78.38 (11) | O10—C14—C11 | 121.1 (3) |
N4—Cd3—O2 | 117.36 (13) | O9—C14—C11 | 115.4 (3) |
N6—Cd4—N9 | 157.59 (16) | O11—C15—O12 | 124.2 (4) |
N6—Cd4—O11 | 74.15 (12) | O11—C15—C13 | 118.9 (4) |
N9—Cd4—O11 | 102.13 (15) | O12—C15—C13 | 116.9 (4) |
N6—Cd4—N10 | 87.82 (15) | N7—C16—C17 | 121.1 (6) |
N9—Cd4—N10 | 70.55 (19) | N7—C16—C21 | 116.9 (5) |
O11—Cd4—N10 | 97.30 (15) | C17—C16—C21 | 121.9 (6) |
N6—Cd4—O2i | 97.24 (13) | C16—C17—C18 | 118.9 (7) |
N9—Cd4—O2i | 101.22 (15) | C16—C17—H17A | 120.6 |
O11—Cd4—O2i | 131.60 (12) | C18—C17—H17A | 120.6 |
N10—Cd4—O2i | 130.45 (14) | C19—C18—C17 | 119.1 (7) |
N6—Cd4—O1i | 116.25 (14) | C19—C18—H18A | 120.5 |
N9—Cd4—O1i | 84.99 (18) | C17—C18—H18A | 120.5 |
O11—Cd4—O1i | 85.61 (12) | C18—C19—C20 | 119.1 (7) |
N10—Cd4—O1i | 155.46 (16) | C18—C19—H19A | 120.4 |
O2i—Cd4—O1i | 55.07 (11) | C20—C19—H19A | 120.4 |
N6—Cd4—C4i | 110.24 (13) | N7—C20—C19 | 122.1 (7) |
N9—Cd4—C4i | 91.90 (16) | N7—C20—H20A | 118.9 |
O11—Cd4—C4i | 109.97 (13) | C19—C20—H20A | 118.9 |
N10—Cd4—C4i | 150.34 (15) | N8—C21—C22 | 121.1 (5) |
O2i—Cd4—C4i | 27.81 (12) | N8—C21—C16 | 116.7 (4) |
O1i—Cd4—C4i | 27.34 (12) | C22—C21—C16 | 122.2 (5) |
N2—N1—C1 | 108.4 (3) | C23—C22—C21 | 119.6 (6) |
N2—N1—Cd3 | 131.8 (3) | C23—C22—H22A | 120.2 |
C1—N1—Cd3 | 118.3 (3) | C21—C22—H22A | 120.2 |
N1—N2—C3 | 107.7 (3) | C24—C23—C22 | 119.3 (5) |
N1—N2—Cd2 | 118.9 (2) | C24—C23—H23A | 120.3 |
C3—N2—Cd2 | 132.3 (3) | C22—C23—H23A | 120.3 |
N4—N3—C8 | 111.5 (3) | C23—C24—C25 | 118.6 (6) |
N4—N3—H3A | 124.2 | C23—C24—H24A | 120.7 |
C8—N3—H3A | 124.2 | C25—C24—H24A | 120.7 |
N3—N4—C6 | 105.5 (3) | N8—C25—C24 | 123.0 (5) |
N3—N4—Cd3 | 141.2 (3) | N8—C25—H25A | 118.5 |
C6—N4—Cd3 | 112.3 (3) | C24—C25—H25A | 118.5 |
N6—N5—C11 | 107.7 (3) | N9—C26—C27 | 120.0 (7) |
N6—N5—Cd2 | 134.0 (3) | N9—C26—C31 | 117.4 (5) |
C11—N5—Cd2 | 118.3 (2) | C27—C26—C31 | 122.6 (7) |
N5—N6—C13 | 108.6 (3) | C26—C27—C28 | 119.1 (8) |
N5—N6—Cd4 | 135.5 (3) | C26—C27—H27A | 120.5 |
C13—N6—Cd4 | 111.9 (3) | C28—C27—H27A | 120.5 |
C20—N7—C16 | 119.6 (5) | C29—C28—C27 | 120.4 (7) |
C20—N7—Cd1 | 122.8 (4) | C29—C28—H28A | 119.8 |
C16—N7—Cd1 | 117.6 (4) | C27—C28—H28A | 119.8 |
C21—N8—C25 | 118.3 (4) | C28—C29—C30 | 118.2 (8) |
C21—N8—Cd1 | 118.1 (3) | C28—C29—H29A | 120.9 |
C25—N8—Cd1 | 123.6 (3) | C30—C29—H29A | 120.9 |
C26—N9—C30 | 119.8 (5) | N9—C30—C29 | 122.6 (8) |
C26—N9—Cd4 | 117.8 (4) | N9—C30—H30A | 118.7 |
C30—N9—Cd4 | 122.2 (4) | C29—C30—H30A | 118.7 |
C35—N10—C31 | 119.7 (5) | N10—C31—C32 | 120.3 (7) |
C35—N10—Cd4 | 123.1 (4) | N10—C31—C26 | 116.7 (5) |
C31—N10—Cd4 | 116.9 (4) | C32—C31—C26 | 123.0 (6) |
C4—O1—Cd4iv | 90.7 (3) | C31—C32—C33 | 119.9 (6) |
C4—O2—Cd4iv | 92.1 (3) | C31—C32—H32A | 120.1 |
C4—O2—Cd3 | 113.0 (3) | C33—C32—H32A | 120.1 |
Cd4iv—O2—Cd3 | 153.67 (15) | C32—C33—C34 | 119.0 (6) |
C5—O3—Cd1 | 81.0 (3) | C32—C33—H33A | 120.5 |
C5—O4—Cd1 | 103.4 (3) | C34—C33—H33A | 120.5 |
C9—O5—Cd2iv | 87.5 (2) | C35—C34—C33 | 118.6 (7) |
C9—O6—Cd3 | 121.3 (3) | C35—C34—H34A | 120.7 |
C9—O6—Cd2iv | 97.1 (2) | C33—C34—H34A | 120.7 |
Cd3—O6—Cd2iv | 141.29 (14) | N10—C35—C34 | 122.5 (6) |
C10—O7—Cd2iii | 84.9 (3) | N10—C35—H35A | 118.8 |
C10—O8—Cd2iii | 97.8 (3) | C34—C35—H35A | 118.8 |
C14—O9—Cd3 | 121.2 (3) | H2C—O2W—H2D | 109.3 |
C14—O9—Cd2 | 118.7 (2) | H3E—O3W—H3F | 112.6 |
Cd3—O9—Cd2 | 119.96 (12) | | |
Symmetry codes: (i) −x+3/2, y−1/2, −z+1/2; (ii) x−1/2, −y+3/2, z+1/2; (iii) −x+2, −y+2, −z+1; (iv) −x+3/2, y+1/2, −z+1/2; (v) x+1/2, −y+3/2, z−1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O7iii | 0.86 | 1.94 | 2.786 (5) | 169 |
O1W—H1A···O8vi | 0.85 | 1.88 | 2.721 (4) | 168 |
O1W—H1B···O3iv | 0.85 | 2.03 | 2.762 (4) | 143 |
O1W—H1B···O10 | 0.85 | 2.68 | 3.177 (5) | 118 |
O2W—H2C···O4 | 0.85 | 2.01 | 2.849 (7) | 171 |
O2W—H2D···O1vii | 0.85 | 2.10 | 2.951 (8) | 178 |
O3W—H3E···O1 | 0.85 | 2.16 | 3.010 (12) | 177 |
O3W—H3F···O2W | 0.85 | 2.23 | 3.079 (14) | 178 |
Symmetry codes: (iii) −x+2, −y+2, −z+1; (iv) −x+3/2, y+1/2, −z+1/2; (vi) x−1/2, −y+5/2, z−1/2; (vii) −x+1, −y+2, −z+1. |
Experimental details
Crystal data |
Chemical formula | [Cd4(C5H2N2O4)(C5HN2O4)2(C10H8N2)2(H2O)]·2H2O |
Mr | 1276.26 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 15.574 (3), 16.197 (3), 16.928 (3) |
β (°) | 109.21 (3) |
V (Å3) | 4032.3 (14) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.17 |
Crystal size (mm) | 0.16 × 0.13 × 0.13 |
|
Data collection |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.72, 0.76 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 38399, 9211, 8760 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.113, 1.08 |
No. of reflections | 9211 |
No. of parameters | 578 |
No. of restraints | 656 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.99, −1.24 |
Selected bond lengths (Å) topCd1—O3 | 2.719 (4) | Cd3—O1W | 2.275 (3) |
Cd1—O4 | 2.216 (3) | Cd3—O2 | 2.482 (3) |
Cd1—O10i | 2.362 (3) | Cd3—O6 | 2.265 (3) |
Cd1—O12ii | 2.206 (3) | Cd3—O9 | 2.227 (3) |
Cd1—N7 | 2.335 (4) | Cd3—N1 | 2.251 (3) |
Cd1—N8 | 2.324 (4) | Cd3—N4 | 2.425 (4) |
Cd2—O5i | 2.575 (3) | Cd4—O1i | 2.408 (4) |
Cd2—O6i | 2.341 (3) | Cd4—O2i | 2.365 (3) |
Cd2—O7iii | 2.619 (3) | Cd4—O11 | 2.332 (3) |
Cd2—O8iii | 2.324 (3) | Cd4—N6 | 2.245 (3) |
Cd2—O9 | 2.423 (3) | Cd4—N9 | 2.329 (4) |
Cd2—N2 | 2.271 (3) | Cd4—N10 | 2.353 (4) |
Cd2—N5 | 2.310 (3) | | |
Symmetry codes: (i) −x+3/2, y−1/2, −z+1/2; (ii) x−1/2, −y+3/2, z+1/2; (iii) −x+2, −y+2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O7iii | 0.86 | 1.94 | 2.786 (5) | 169.2 |
O1W—H1A···O8iv | 0.85 | 1.88 | 2.721 (4) | 168.1 |
O1W—H1B···O3v | 0.85 | 2.03 | 2.762 (4) | 143.2 |
O1W—H1B···O10 | 0.85 | 2.68 | 3.177 (5) | 118.4 |
O2W—H2C···O4 | 0.85 | 2.01 | 2.849 (7) | 170.9 |
O2W—H2D···O1vi | 0.85 | 2.10 | 2.951 (8) | 177.7 |
O3W—H3E···O1 | 0.85 | 2.16 | 3.010 (12) | 177.4 |
O3W—H3F···O2W | 0.85 | 2.23 | 3.079 (14) | 177.7 |
Symmetry codes: (iii) −x+2, −y+2, −z+1; (iv) x−1/2, −y+5/2, z−1/2; (v) −x+3/2, y+1/2, −z+1/2; (vi) −x+1, −y+2, −z+1. |
The assembly of metal–organic frameworks (MOFs) has attracted much attention due not only to their potential applications in gas adsorption, photochemical areas, magnetism and catalysis, but also to their intriguing topologies (Ferey et al., 2005). However, one of the biggest challenges is how to rationally design new materials and construct the related frameworks with desired structures and properties. In this regard, self-assembly of the organic ligands containing N- and/or O-donor atoms as building blocks, especially polycarboxylic acids, and transition metal ions under hydrothermal conditions, has been documented to be one of the most efficient and fruitful methods (Zhao et al., 2011). Up to now, a variety of MOFs with one-, two- and three-dimensional structures have been constructed by assembling transition metals and polycarboxylic acids such as benzene-1,3,5-tricarboxylate acid, benzene-1,4-bicarboxylate acid, and so on, due to their rigidity as building blocks and the variety of their coordination modes (Dincã & Long, 2008; Tong et al., 2011; Li et al., 1998). Recently, pyrazole-3,5-dicarboxylic acid has been employed to assemble MOFs because it is an intriguing multidentate ligand with two nitrogen donors from the corresponding pyrazole ring and two carboxylate groups as coordination sites (Pan, Huang & Li, 2000; Pan, Huang, Li, Wu et al., 2000). The participation of the N atoms of the pyrazole ring together or individually may lead to unusual multidimensional architectures because of its flexible coordination modes, which may be tuned by the pH value of the reaction mixture removing the nitrogen proton (Pan, Huang & Li, 2000; Pan, Huang, Li, Wu et al., 2000). To date, coordination polymers containing pyrazole-3,5-dicarboxylic acid and CdII ions have rarely been investigated (Pan et al., 2001). In contrast to other transition metals, interestingly, the Cd atoms could provide different coordination numbers in one compound, which could determine the magnitude of the channel of the desired MOFs (Xia et al., 2004). We report here the synthesis and structural characterization of a three-dimensional Cd coordination polymer, namely poly[[aquadi(2,2'-bipyridine)(µ5-pyrazol-1-ide-3,5-dicarboxylato)(µ4-pyrazol-1-ide-3,5-dicarboxylato)(µ3-pyrazole-3,5-dicarboxylato)tetracadmium(II)] dihydrate], (I), which demonstrates a variety of coordination modes of pyrazole-3,5-dicarboxylic acid and two kinds of coordination numbers of the Cd atoms.
Single-crystal structure analysis reveals that (I) crystallized in the monoclinic space group P21/n and exhibits a three-dimensional architecture. The asymmetric unit of (I) consists of four crystallographically independent CdII ions, two triply deprotonated pyrazole-3,5-dicarboxylic acid molecules, one doubly deprotonated pyrazole-3,5-dicarboxylic acid molecule, two 2,2'-bipyridine, one coordinated water molecule and two interstitial water molecules (Fig. 1). The Cd1 atom is hexacoordinated and adopts a distorted octahedral arrangement defined by two 2,2'-bipyridine N atoms in a chelating mode and four carboxylate O atoms from two different anionic ligands, viz pyrazol-1-ide-3,5-dicarboxylate (PDC) and pyrazole-3,5-dicarboxylate (HPDC). The equatorial plane of the Cd1 geometry is composed of atoms N7, N8, O4 and O10; two apical positions are occupied by O3 and O12 from two different PDC ligands. The small chelating angles of 70.70 (16) (N7—Cd1—N8 from 2,2-bpy) and 52.01 (10)° (O3—Cd1—O4 from the same carboxylate group) reflect the distortion of the Cd1 geometry, as do the Cd1—N,O bond lengths [2.206 (3)–2.719 (4) Å; Table 1], which are typical for such coordination geometries reported in the literature (Fang & Zhang, 2006). Whereas [In contrast] the Cd2 center is heptacoordinated and lies in a pentagonal–bipyramidal geometry constructed by five carboxylate O atoms (O5, O6, O7, O8 and O9) from two different PDC and one HPDC unit, and two N atoms (N2 and N5) from two separate pyrazole rings. Atoms N2 and N5 occupy two axial positions and the other atoms (O5, O6, O7, O8 and O9) form the equatorial pentagonal planes. The Cd—O bond lengths involving Cd2 range from 2.271 (3) to 2.619 (3) Å and the angles vary from 52.88 (10) to 115.78 (12)°. It is worth noting that the Cd2—O5 and Cd2—O7 bond lengths are much longer than the others, probably due to stereochemical requirements (O5 and O7 sit on two axial sites). Similar to Cd1, both Cd3 and Cd4 are hexacoordinated, but the coordination geometries are different. Atom Cd3 displays a trigonal prismatic geometry by two sets of chelated N and O atoms from µ3-HPDC and µ4-PDC, respectively, a bridging carboxylate O atom of µ5-PDC and a terminal water molecule. However, atom Cd4, like Cd1, is located in a very distorted octahedral geometry, the equatorial plane of which is composed of N6, O1 and two 2,2-bipyridine N atoms, with the axial positions occupied by two carboxylate O atoms from µ4-PDC and µ5-PDC. Apparently, the Cd3 polyhedron shares one vertex with that of Cd4 through O2 and those of two separate adjacent Cd2 through O6 and O9, respectively. It should be noted that the Cd3—O1W bond length [2.275 (3) Å] is significantly longer than those of coordinated hydroxy groups, excluding the possibility that O1W could be a hydroxy group (Bruno et al., 2002).
Interestingly, the three crystallographically independent anionic ligands show different coordination modes in this complex, viz. µ5, µ4 and µ3. µ5-PDC chelates two Cd atoms (Cd2 and Cd4) through O9 and N5, and O11 and N6, respectively, and bridges two adjacent atoms (Cd1) from different units with O10 and O12, respectively. The polyhedra of the Cd2 and Cd3 centers share apex atom O9 from µ5-PDC and O6 from µ3-PDC together alternatively to form a wave-like nano-band along the b axis (Figs. 2 and 3). The adjacent wave-like bands are bridged to form a two-dimensional wave-like layer through carboxylate groups (O12 and O11) of µ5-PDC. µ3-HPDC bridges one Cd atom (Cd2) with one carboxylate group and two Cd atoms (Cd2 and Cd3) from an adjacent layer through the other carboxylate group and an N atom (N1) of the pyrazole ring to form a three-dimensional framework, but leaves atom N3 free with one H atom, which was confirmed by the N—H stretching vibration at 3424 cm-1 (Pan, Huang & Li, 2000; Pan, Huang, Li, Wu et al., 2000). The other point to note is that each carboxylate group is almost in the plane of correspondingly linking pyrazole rings [the dihedral angles between them ranging from 3.264 (5) to 11.887 (1) Å].
The CdII ions show two different coordination numbers (six and seven) in (I), which are also found in the literature (Wang et al., 2007). The water molecules fill the molecular cavities, which leads to a lack of a solvent-accessible void due to the coordinated 2,2'-bipyridine (77 Å, 1.9% of the whole unit-cell volume solvent-accessible void calculated using the SQUEEZE method in PLATON; Spek, 2009). Furthermore, hydrogen bonds (Table 2) between water molecules (O1W, O2W and O3W) and the carboxylate O atoms (O1, O3, O4, O8 and O10) of the framework, and between a pyrazole N atom (N3) and the carboxylate O7 atom, further enhance the stability of the three-dimensional structure.