Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807041281/bt2480sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807041281/bt2480Isup2.hkl |
CCDC reference: 281905
Key indicators
- Single-crystal X-ray study
- T = 193 K
- Mean (C-C) = 0.003 Å
- R factor = 0.035
- wR factor = 0.092
- Data-to-parameter ratio = 16.1
checkCIF/PLATON results
No syntax errors found
Alert level G PLAT794_ALERT_5_G Check Predicted Bond Valency for Ni1 (2) 2.04
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 0 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
A 25 ml H2O/EtOH solution (v/v, 1:1) of 1,4-bis(1,2,4-triazol-1- ylmethyl)benzene (bbtz) (0.240 g, 1.0 mmol) was added to one leg of a H-shape tube, and 25 ml H2O/EtOH (v/v, 1:1) solution of Ni(NO3)2.6H2O (0.145 g, 0.5 mmol) and NaOCN (0.088 g, 1.4 mmol) was added to the other leg of the tube. The tube was allowed to stand in air at the room temperature for about one month. The light-blue crystals [Ni(bbtz)2(NCO)2]n (I) suitable for X-ray diffraction were obtained. Yield 73%. Elemental analysis confirmed the organic content (Found: C, 49.96; H, 3.82; N, 31.38%. Calcd. for C26H24N14NiO2: C, 50.10; H, 3.88; N, 31.47%).
H atom were placed in idealized positions and refined as riding, with C—H distances of 0.95 (triazole and benzene) and 0.99Å (methyl), and with Uiso(H) = 1.2Ueq(C).
The design and assembly of coordination polymers have been intensely studied for their interesting topologies and potential application as functional materials. The structural motifs of coordination polymers rest on several factors, such as the central atom, the performance of the ligands, the coordinated and/or non-coordinated counter ions and the reaction conditions. The ligand is no doubt the key factor of manipulating the topologies of the coordination polymers. Some novel coordination polymers with the flexible bis(triazole) ligands have been synthesized (Haasnoot, 2000; Albada et al., 2000; Zhao et al., 2002; Meng et al., 2004; Li et al., 2005).
In our previous studies, we synthesized several coordination polymers with the flexible ligands 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) (Li et al., 2004; Li et al., 2005; Wang et al., 2007). In the present paper, we report the preparation and crystal structure of a two-dimensional (4,4) network coordination polymer [Ni(bbtz)2(NCO)2]n (I).
The structure of (I) is similar to that of [Ni(bbtz)2(N3)2]n (Wang et al., 2007). Fig. 1 shows the local coordination of the NiII atom in (I). The complex has a center of symmetry and the NiII atom occupies an inversion center. The coordination geometry of the NiII atom is distorted octahedral; it is coordinated equatorially by four nitrogen atoms from the triazole rings of four symmetry-related bbtz ligands [Ni1—N3, 2.1156 (3) Å; Ni1—N6 (-x + 1, y - 1/2, -z - 1/2), 2.1195 (14) Å], and axially by two nitrogen atoms from two symmetry-related cyanate anions [Ni1—N7, 2.0672 (16) Å]. The Ni—N(triazole) bond lengths [2.1156 (3) and 2.1195 (14) Å] at equatorial plane in (I) are corresponding to the values [2.1012 (16) and 2.1162 (16) Å] reported in [Ni(bbtz)2(N3)2]n (Wang et al., 2007). The cyanato ligand in (I) is quasi-linear as expected [the N—C—O bond angle is 178.3 (2)°]. The Ni—N—C (NCO) bond angle is 169.80 (15)°.
Because the methyl carbon atoms of bbtz can freely rotate to adjust itself to the coordination environment, bbtz can exhibit the trans-gauche and gauche-gauche conformations. The bbtz ligands exhibit the trans-gauche conformation in (I), similar to the situation in the free bbtz molecule (Peng et al., 2004), [Ni(bbtz)2(N3)2]n (Wang et al., 2007) and [Co(bbtz)2(N3)2]n (Li et al., 2004). The three rings (two triazole rings and one benzene ring) of one bbtz ligand are not coplanar in (I), [Ni(bbtz)2(N3)2]n, [Co(bbtz)2(N3)2]n and the free bbtz molecule. The dihedral angle between the two triazole planes in (I) is 58.8 (1)°, compared with the values 63.70 (9)° in [Ni(bbtz)2(N3)2]n, 61.94 (19)° in [Co(bbtz)2(N3)2]n, but 0° in free bbtz molecule by imposed crystallographic symmetry. The dihedral angles between the benzene plane and triazole planes in (I) are 67.6 (1) and 65.8 (1)°, compared with the values 66.46 (9) and 66.10 (7)° in [Ni(bbtz)2(N3)2]n, 67.26 (9) and 66.96 (7)° in [Co(bbtz)2(N3)2]n, and 77.81 (9)° in the free bbtz molecule.
As illustrated in Fig. 2, each bbtz ligand in (I) coordinates to the NiII atoms through its two triazole nitrogen atoms, thus acting as a bridging bidentate ligand to form a two-dimensional neutral (4,4) network. The networks contain square grids (52-membered ring), with a NiII atom at each corner and a bbtz ligand at each edge connecting two NiII atoms. As a consequence of the symmetry of the crystal structure, the edge lengths are equal, with a value of 14.383 (1) Å, similar to the M···M separations [14.3646 (15) Å] in [Ni(bbtz)2(N3)2]n (Wang et al., 2007), and [14.4156 (18) Å] in [Co(bbtz)2(N3)2]n (Li et al., 2004).
The diagonal lengths of the square grid are 20.191 (1) and 20.489 (1) Å; the square angles are 90.8 (1) and 89.2 (1)°. The square-grid sheets are stacked in an off-set fashion parallel to the c direction. The off-set half-cell superposition of each pair of adjacent networks divides the voids into smaller rectangle. The cyanate anions of one sheet project into the holes of the next sheet. In the superposition structure, the sheets are arranged in the sequence ··· A—B—A—B ···(Fig.3).
The synthesis of the ligand 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) is described by Peng et al. (2004). Several bbtz complexes have been synthesized and structurally characterized (Li et al., 2004, 2005; Wang et al., 2007). The complex [Ni(bbtz)2(N3)2]n has a similar two-dimensional (4,4) network (Wang et al., 2007). For flexible bis(triazole) ligands, see: Haasnoot (2000); Albada et al. (2000); Zhao et al. (2002); Meng et al. (2004).
Data collection: CrystalClear (Rigaku, 2000); cell refinement: CrystalClear (Rigaku, 2000); data reduction: CrystalClear (Rigaku, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXTL (Bruker, 1998).
[Ni(CNO)2(C12H12N6)2] | F(000) = 644 |
Mr = 623.30 | Dx = 1.495 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5408 reflections |
a = 8.3857 (7) Å | θ = 3.0–27.5° |
b = 20.1913 (14) Å | µ = 0.75 mm−1 |
c = 8.4229 (7) Å | T = 193 K |
β = 103.836 (2)° | Prism, light-blue |
V = 1384.77 (19) Å3 | 0.50 × 0.20 × 0.20 mm |
Z = 2 |
Rigaku Mercury CCD diffractometer | 3168 independent reflections |
Radiation source: fine-focus sealed tube | 2828 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
Detector resolution: 7.31 pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ω scans | h = −10→10 |
Absorption correction: multi-scan (Jacobson, 1998) | k = −23→26 |
Tmin = 0.704, Tmax = 0.864 | l = −8→10 |
15292 measured reflections |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.092 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.047P)2 + 0.5612P] where P = (Fo2 + 2Fc2)/3 |
3168 reflections | (Δ/σ)max < 0.001 |
197 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
[Ni(CNO)2(C12H12N6)2] | V = 1384.77 (19) Å3 |
Mr = 623.30 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.3857 (7) Å | µ = 0.75 mm−1 |
b = 20.1913 (14) Å | T = 193 K |
c = 8.4229 (7) Å | 0.50 × 0.20 × 0.20 mm |
β = 103.836 (2)° |
Rigaku Mercury CCD diffractometer | 3168 independent reflections |
Absorption correction: multi-scan (Jacobson, 1998) | 2828 reflections with I > 2σ(I) |
Tmin = 0.704, Tmax = 0.864 | Rint = 0.027 |
15292 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.092 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.28 e Å−3 |
3168 reflections | Δρmin = −0.25 e Å−3 |
197 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Ni1 | 0.0000 | 0.5000 | 0.5000 | 0.02367 (11) | |
O1 | 0.51308 (17) | 0.53499 (8) | 0.77007 (19) | 0.0498 (4) | |
N1 | 0.14183 (18) | 0.58347 (7) | 0.09373 (17) | 0.0285 (3) | |
N2 | −0.0216 (2) | 0.58482 (9) | 0.0260 (2) | 0.0395 (4) | |
N3 | 0.02897 (17) | 0.54577 (7) | 0.28271 (17) | 0.0270 (3) | |
N4 | 0.80765 (18) | 0.83698 (7) | 0.20798 (18) | 0.0302 (3) | |
N5 | 0.9361 (2) | 0.80325 (8) | 0.1727 (2) | 0.0388 (4) | |
N6 | 0.92675 (17) | 0.90787 (7) | 0.08018 (17) | 0.0275 (3) | |
N7 | 0.24273 (19) | 0.52223 (8) | 0.60611 (19) | 0.0337 (3) | |
C1 | 0.3763 (2) | 0.65567 (9) | 0.0773 (2) | 0.0295 (4) | |
C2 | 0.5224 (2) | 0.64025 (9) | 0.1849 (3) | 0.0390 (4) | |
H2A | 0.5502 | 0.5952 | 0.2091 | 0.047* | |
C3 | 0.6300 (2) | 0.68970 (10) | 0.2586 (2) | 0.0388 (4) | |
H3A | 0.7306 | 0.6781 | 0.3324 | 0.047* | |
C4 | 0.5919 (2) | 0.75545 (9) | 0.2256 (2) | 0.0312 (4) | |
C5 | 0.4459 (3) | 0.77098 (10) | 0.1158 (3) | 0.0435 (5) | |
H5A | 0.4185 | 0.8161 | 0.0911 | 0.052* | |
C6 | 0.3389 (3) | 0.72163 (10) | 0.0412 (3) | 0.0435 (5) | |
H6A | 0.2396 | 0.7331 | −0.0348 | 0.052* | |
C7 | 0.2624 (2) | 0.60073 (10) | −0.0015 (2) | 0.0370 (4) | |
H7A | 0.2033 | 0.6147 | −0.1127 | 0.044* | |
H7B | 0.3282 | 0.5610 | −0.0123 | 0.044* | |
C8 | −0.0831 (2) | 0.56153 (10) | 0.1443 (2) | 0.0347 (4) | |
H8A | −0.1978 | 0.5562 | 0.1333 | 0.042* | |
C9 | 0.1696 (2) | 0.56019 (9) | 0.2452 (2) | 0.0311 (4) | |
H9A | 0.2752 | 0.5547 | 0.3164 | 0.037* | |
C10 | 0.7068 (3) | 0.80889 (10) | 0.3107 (2) | 0.0382 (4) | |
H10A | 0.6415 | 0.8447 | 0.3445 | 0.046* | |
H10B | 0.7797 | 0.7902 | 0.4107 | 0.046* | |
C11 | 1.0026 (2) | 0.84856 (9) | 0.0954 (2) | 0.0349 (4) | |
H11A | 1.0964 | 0.8400 | 0.0539 | 0.042* | |
C12 | 0.8044 (2) | 0.89849 (9) | 0.1525 (2) | 0.0288 (4) | |
H12A | 0.7260 | 0.9311 | 0.1630 | 0.035* | |
C13 | 0.3752 (2) | 0.52878 (8) | 0.6844 (2) | 0.0275 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.02108 (17) | 0.02854 (18) | 0.02304 (17) | 0.00161 (11) | 0.00850 (12) | 0.00138 (11) |
O1 | 0.0248 (7) | 0.0645 (10) | 0.0567 (9) | −0.0067 (7) | 0.0029 (6) | 0.0001 (8) |
N1 | 0.0284 (7) | 0.0334 (8) | 0.0251 (7) | −0.0067 (6) | 0.0090 (6) | 0.0005 (6) |
N2 | 0.0329 (9) | 0.0497 (10) | 0.0341 (8) | −0.0023 (7) | 0.0045 (7) | 0.0115 (7) |
N3 | 0.0267 (7) | 0.0296 (7) | 0.0265 (7) | 0.0014 (6) | 0.0099 (6) | 0.0027 (6) |
N4 | 0.0312 (8) | 0.0307 (8) | 0.0299 (7) | −0.0074 (6) | 0.0097 (6) | −0.0030 (6) |
N5 | 0.0357 (9) | 0.0328 (8) | 0.0495 (10) | −0.0002 (7) | 0.0133 (8) | −0.0016 (7) |
N6 | 0.0253 (7) | 0.0305 (7) | 0.0283 (7) | −0.0027 (6) | 0.0094 (6) | −0.0013 (6) |
N7 | 0.0260 (8) | 0.0438 (9) | 0.0318 (8) | −0.0009 (7) | 0.0080 (6) | 0.0012 (7) |
C1 | 0.0314 (9) | 0.0327 (9) | 0.0272 (8) | −0.0065 (7) | 0.0127 (7) | 0.0027 (7) |
C2 | 0.0404 (11) | 0.0285 (9) | 0.0472 (11) | −0.0008 (8) | 0.0089 (9) | 0.0058 (8) |
C3 | 0.0333 (10) | 0.0380 (10) | 0.0411 (10) | −0.0027 (8) | 0.0007 (8) | 0.0089 (8) |
C4 | 0.0343 (9) | 0.0333 (9) | 0.0288 (8) | −0.0070 (7) | 0.0132 (7) | 0.0011 (7) |
C5 | 0.0406 (11) | 0.0298 (10) | 0.0576 (13) | 0.0006 (8) | 0.0071 (10) | 0.0090 (9) |
C6 | 0.0329 (10) | 0.0426 (11) | 0.0503 (12) | −0.0016 (8) | 0.0010 (9) | 0.0096 (9) |
C7 | 0.0396 (10) | 0.0469 (11) | 0.0289 (9) | −0.0135 (9) | 0.0168 (8) | −0.0041 (8) |
C8 | 0.0263 (9) | 0.0429 (10) | 0.0352 (9) | 0.0020 (8) | 0.0080 (7) | 0.0089 (8) |
C9 | 0.0254 (8) | 0.0418 (10) | 0.0268 (8) | −0.0027 (7) | 0.0079 (7) | 0.0029 (7) |
C10 | 0.0481 (11) | 0.0390 (10) | 0.0310 (9) | −0.0141 (9) | 0.0164 (8) | −0.0021 (8) |
C11 | 0.0294 (9) | 0.0347 (10) | 0.0427 (10) | −0.0022 (7) | 0.0128 (8) | −0.0038 (8) |
C12 | 0.0269 (8) | 0.0305 (9) | 0.0301 (9) | −0.0031 (7) | 0.0092 (7) | −0.0028 (7) |
C13 | 0.0277 (9) | 0.0258 (9) | 0.0322 (9) | −0.0004 (7) | 0.0134 (7) | 0.0025 (7) |
Ni1—N7i | 2.0672 (15) | C1—C2 | 1.374 (3) |
Ni1—N7 | 2.0672 (16) | C1—C6 | 1.385 (3) |
Ni1—N3i | 2.1156 (13) | C1—C7 | 1.510 (3) |
Ni1—N3 | 2.1156 (13) | C2—C3 | 1.388 (3) |
Ni1—N6ii | 2.1195 (14) | C2—H2A | 0.9500 |
Ni1—N6iii | 2.1195 (14) | C3—C4 | 1.378 (3) |
O1—C13 | 1.214 (2) | C3—H3A | 0.9500 |
N1—C9 | 1.327 (2) | C4—C5 | 1.382 (3) |
N1—N2 | 1.353 (2) | C4—C10 | 1.509 (3) |
N1—C7 | 1.475 (2) | C5—C6 | 1.387 (3) |
N2—C8 | 1.314 (2) | C5—H5A | 0.9500 |
N3—C9 | 1.325 (2) | C6—H6A | 0.9500 |
N3—C8 | 1.349 (2) | C7—H7A | 0.9900 |
N4—C12 | 1.325 (2) | C7—H7B | 0.9900 |
N4—N5 | 1.366 (2) | C8—H8A | 0.9500 |
N4—C10 | 1.461 (2) | C9—H9A | 0.9500 |
N5—C11 | 1.321 (2) | C10—H10A | 0.9900 |
N6—C12 | 1.326 (2) | C10—H10B | 0.9900 |
N6—C11 | 1.347 (2) | C11—H11A | 0.9500 |
N6—Ni1iv | 2.1195 (14) | C12—H12A | 0.9500 |
N7—C13 | 1.156 (2) | ||
N7i—Ni1—N7 | 180.0 | C4—C3—H3A | 119.7 |
N7i—Ni1—N3i | 88.53 (6) | C2—C3—H3A | 119.7 |
N7—Ni1—N3i | 91.47 (6) | C3—C4—C5 | 118.61 (17) |
N7i—Ni1—N3 | 91.47 (6) | C3—C4—C10 | 120.15 (18) |
N7—Ni1—N3 | 88.53 (6) | C5—C4—C10 | 121.23 (18) |
N3i—Ni1—N3 | 180.0 | C4—C5—C6 | 120.90 (18) |
N7i—Ni1—N6ii | 90.12 (6) | C4—C5—H5A | 119.5 |
N7—Ni1—N6ii | 89.88 (6) | C6—C5—H5A | 119.5 |
N3i—Ni1—N6ii | 89.67 (5) | C1—C6—C5 | 120.22 (19) |
N3—Ni1—N6ii | 90.33 (5) | C1—C6—H6A | 119.9 |
N7i—Ni1—N6iii | 89.88 (6) | C5—C6—H6A | 119.9 |
N7—Ni1—N6iii | 90.12 (6) | N1—C7—C1 | 112.26 (14) |
N3i—Ni1—N6iii | 90.33 (5) | N1—C7—H7A | 109.2 |
N3—Ni1—N6iii | 89.67 (5) | C1—C7—H7A | 109.2 |
N6ii—Ni1—N6iii | 180.0 | N1—C7—H7B | 109.2 |
C9—N1—N2 | 109.87 (14) | C1—C7—H7B | 109.2 |
C9—N1—C7 | 128.37 (16) | H7A—C7—H7B | 107.9 |
N2—N1—C7 | 121.56 (15) | N2—C8—N3 | 114.90 (16) |
C8—N2—N1 | 102.41 (14) | N2—C8—H8A | 122.6 |
C9—N3—C8 | 102.61 (14) | N3—C8—H8A | 122.6 |
C9—N3—Ni1 | 126.55 (12) | N3—C9—N1 | 110.21 (16) |
C8—N3—Ni1 | 130.56 (12) | N3—C9—H9A | 124.9 |
C12—N4—N5 | 109.95 (14) | N1—C9—H9A | 124.9 |
C12—N4—C10 | 127.36 (16) | N4—C10—C4 | 113.01 (15) |
N5—N4—C10 | 122.24 (16) | N4—C10—H10A | 109.0 |
C11—N5—N4 | 102.10 (15) | C4—C10—H10A | 109.0 |
C12—N6—C11 | 103.21 (15) | N4—C10—H10B | 109.0 |
C12—N6—Ni1iv | 125.93 (12) | C4—C10—H10B | 109.0 |
C11—N6—Ni1iv | 130.10 (12) | H10A—C10—H10B | 107.8 |
C13—N7—Ni1 | 169.80 (15) | N5—C11—N6 | 114.67 (16) |
C2—C1—C6 | 118.82 (17) | N5—C11—H11A | 122.7 |
C2—C1—C7 | 119.59 (17) | N6—C11—H11A | 122.7 |
C6—C1—C7 | 121.57 (18) | N6—C12—N4 | 110.07 (16) |
C1—C2—C3 | 120.89 (18) | N6—C12—H12A | 125.0 |
C1—C2—H2A | 119.6 | N4—C12—H12A | 125.0 |
C3—C2—H2A | 119.6 | N7—C13—O1 | 178.3 (2) |
C4—C3—C2 | 120.54 (18) | ||
C9—N1—N2—C8 | −0.1 (2) | C7—C1—C6—C5 | 179.90 (19) |
C7—N1—N2—C8 | 175.07 (17) | C4—C5—C6—C1 | 0.7 (3) |
N7i—Ni1—N3—C9 | −163.56 (15) | C9—N1—C7—C1 | −61.6 (3) |
N7—Ni1—N3—C9 | 16.44 (15) | N2—N1—C7—C1 | 124.14 (19) |
N6ii—Ni1—N3—C9 | −73.44 (15) | C2—C1—C7—N1 | 91.4 (2) |
N6iii—Ni1—N3—C9 | 106.56 (15) | C6—C1—C7—N1 | −89.9 (2) |
N7i—Ni1—N3—C8 | 9.20 (17) | N1—N2—C8—N3 | 0.3 (2) |
N7—Ni1—N3—C8 | −170.80 (17) | C9—N3—C8—N2 | −0.4 (2) |
N6ii—Ni1—N3—C8 | 99.33 (17) | Ni1—N3—C8—N2 | −174.48 (13) |
N6iii—Ni1—N3—C8 | −80.67 (17) | C8—N3—C9—N1 | 0.3 (2) |
C12—N4—N5—C11 | −0.2 (2) | Ni1—N3—C9—N1 | 174.71 (11) |
C10—N4—N5—C11 | −173.03 (16) | N2—N1—C9—N3 | −0.2 (2) |
N3i—Ni1—N7—C13 | 8.8 (9) | C7—N1—C9—N3 | −174.92 (16) |
N3—Ni1—N7—C13 | −171.2 (9) | C12—N4—C10—C4 | 115.0 (2) |
N6ii—Ni1—N7—C13 | −80.8 (9) | N5—N4—C10—C4 | −73.5 (2) |
N6iii—Ni1—N7—C13 | 99.2 (9) | C3—C4—C10—N4 | 101.5 (2) |
C6—C1—C2—C3 | 1.0 (3) | C5—C4—C10—N4 | −79.7 (2) |
C7—C1—C2—C3 | 179.69 (18) | N4—N5—C11—N6 | 0.3 (2) |
C1—C2—C3—C4 | 0.2 (3) | C12—N6—C11—N5 | −0.2 (2) |
C2—C3—C4—C5 | −1.0 (3) | Ni1iv—N6—C11—N5 | 170.08 (13) |
C2—C3—C4—C10 | 177.90 (18) | C11—N6—C12—N4 | 0.11 (19) |
C3—C4—C5—C6 | 0.6 (3) | Ni1iv—N6—C12—N4 | −170.75 (11) |
C10—C4—C5—C6 | −178.32 (19) | N5—N4—C12—N6 | 0.0 (2) |
C2—C1—C6—C5 | −1.5 (3) | C10—N4—C12—N6 | 172.43 (16) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, y−1/2, −z+1/2; (iii) x−1, −y+3/2, z+1/2; (iv) −x+1, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [Ni(CNO)2(C12H12N6)2] |
Mr | 623.30 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 193 |
a, b, c (Å) | 8.3857 (7), 20.1913 (14), 8.4229 (7) |
β (°) | 103.836 (2) |
V (Å3) | 1384.77 (19) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.75 |
Crystal size (mm) | 0.50 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Rigaku Mercury CCD |
Absorption correction | Multi-scan (Jacobson, 1998) |
Tmin, Tmax | 0.704, 0.864 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15292, 3168, 2828 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.092, 1.06 |
No. of reflections | 3168 |
No. of parameters | 197 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.28, −0.25 |
Computer programs: CrystalClear (Rigaku, 2000), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1998).
The design and assembly of coordination polymers have been intensely studied for their interesting topologies and potential application as functional materials. The structural motifs of coordination polymers rest on several factors, such as the central atom, the performance of the ligands, the coordinated and/or non-coordinated counter ions and the reaction conditions. The ligand is no doubt the key factor of manipulating the topologies of the coordination polymers. Some novel coordination polymers with the flexible bis(triazole) ligands have been synthesized (Haasnoot, 2000; Albada et al., 2000; Zhao et al., 2002; Meng et al., 2004; Li et al., 2005).
In our previous studies, we synthesized several coordination polymers with the flexible ligands 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) (Li et al., 2004; Li et al., 2005; Wang et al., 2007). In the present paper, we report the preparation and crystal structure of a two-dimensional (4,4) network coordination polymer [Ni(bbtz)2(NCO)2]n (I).
The structure of (I) is similar to that of [Ni(bbtz)2(N3)2]n (Wang et al., 2007). Fig. 1 shows the local coordination of the NiII atom in (I). The complex has a center of symmetry and the NiII atom occupies an inversion center. The coordination geometry of the NiII atom is distorted octahedral; it is coordinated equatorially by four nitrogen atoms from the triazole rings of four symmetry-related bbtz ligands [Ni1—N3, 2.1156 (3) Å; Ni1—N6 (-x + 1, y - 1/2, -z - 1/2), 2.1195 (14) Å], and axially by two nitrogen atoms from two symmetry-related cyanate anions [Ni1—N7, 2.0672 (16) Å]. The Ni—N(triazole) bond lengths [2.1156 (3) and 2.1195 (14) Å] at equatorial plane in (I) are corresponding to the values [2.1012 (16) and 2.1162 (16) Å] reported in [Ni(bbtz)2(N3)2]n (Wang et al., 2007). The cyanato ligand in (I) is quasi-linear as expected [the N—C—O bond angle is 178.3 (2)°]. The Ni—N—C (NCO) bond angle is 169.80 (15)°.
Because the methyl carbon atoms of bbtz can freely rotate to adjust itself to the coordination environment, bbtz can exhibit the trans-gauche and gauche-gauche conformations. The bbtz ligands exhibit the trans-gauche conformation in (I), similar to the situation in the free bbtz molecule (Peng et al., 2004), [Ni(bbtz)2(N3)2]n (Wang et al., 2007) and [Co(bbtz)2(N3)2]n (Li et al., 2004). The three rings (two triazole rings and one benzene ring) of one bbtz ligand are not coplanar in (I), [Ni(bbtz)2(N3)2]n, [Co(bbtz)2(N3)2]n and the free bbtz molecule. The dihedral angle between the two triazole planes in (I) is 58.8 (1)°, compared with the values 63.70 (9)° in [Ni(bbtz)2(N3)2]n, 61.94 (19)° in [Co(bbtz)2(N3)2]n, but 0° in free bbtz molecule by imposed crystallographic symmetry. The dihedral angles between the benzene plane and triazole planes in (I) are 67.6 (1) and 65.8 (1)°, compared with the values 66.46 (9) and 66.10 (7)° in [Ni(bbtz)2(N3)2]n, 67.26 (9) and 66.96 (7)° in [Co(bbtz)2(N3)2]n, and 77.81 (9)° in the free bbtz molecule.
As illustrated in Fig. 2, each bbtz ligand in (I) coordinates to the NiII atoms through its two triazole nitrogen atoms, thus acting as a bridging bidentate ligand to form a two-dimensional neutral (4,4) network. The networks contain square grids (52-membered ring), with a NiII atom at each corner and a bbtz ligand at each edge connecting two NiII atoms. As a consequence of the symmetry of the crystal structure, the edge lengths are equal, with a value of 14.383 (1) Å, similar to the M···M separations [14.3646 (15) Å] in [Ni(bbtz)2(N3)2]n (Wang et al., 2007), and [14.4156 (18) Å] in [Co(bbtz)2(N3)2]n (Li et al., 2004).
The diagonal lengths of the square grid are 20.191 (1) and 20.489 (1) Å; the square angles are 90.8 (1) and 89.2 (1)°. The square-grid sheets are stacked in an off-set fashion parallel to the c direction. The off-set half-cell superposition of each pair of adjacent networks divides the voids into smaller rectangle. The cyanate anions of one sheet project into the holes of the next sheet. In the superposition structure, the sheets are arranged in the sequence ··· A—B—A—B ···(Fig.3).