Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S205322961402052X/sk3551sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S205322961402052X/sk3551Isup2.hkl |
CCDC reference: 1024107
The current interest in the crystal engineering of coordination polymer frameworks, more commonly known as metal–organic frameworks (MOFs), not only stems from their intriguing variety of architectures and topologies, but also from their potential applications in the areas of nonlinear optics, catalysis, magnetism, luminescence, gas storage and biological recognition (Rao et al., 2004; Wang, Qin, Wang, Li et al., 2004; Wang, Qin, Wang, Xu et al., 2004; Wang, Zhang et al., 2004; Dybtsev et al., 2006; He et al., 2005; Koh et al., 2009). Despite significant progress in the synthesis of numerous polymeric metal–organic coordination networks in recent years, it is still a challenging task to explore a generally successful approach to predict and control the structures of coordination networks assembled from a particular combination of metal centres and bridging ligands (Evans & Lin; 2000; Yao et al., 2009; Fang et al., 2008). MOFs are primarily constructed from mononuclear metal centres and organic ligands, known as node and spacer, respectively, and this has resulted in a tremendous number of intriguing network topologies and a variety of packing motifs (Kitagawa et al., 2004; Bradshaw et al., 2005).
Recently, more attention has been paid to expanding the classical `Aufbau principles' to include polynuclear coordination clusters as building units, with the intention of utilizing them as nodes in the design of coordination polymers (Marin et al., 2004; Perry et al., 2007). This represents an extension of the classical `node-and-spacer' approach (Robson, 2000), giving rise to a family of cluster-based polymers with an enhanced variety of coordination geometries compared with single metal ions.
Poly-aza heterocyclic compounds have attracted considerable attention as useful ligands to produce coordination polymers with useful functional properties, such as gas storage (Zhang & Chen, 2008), magnetism (Ma et al., 2010; Wang et al., 2010) and catalysis (Wu et al., 2005). Among these poly-aza heterocyclic compounds, 5-amino-tetrazole (Hatz) is a rigid multidentate organic ligand that potentially possesses the capability to bridge metal atoms in various coordination modes via the N atoms of the tetrazole ring.
During our recent work on MOFs containing 5-amino-tetrazole, we found that Cd3(µ3-OH) is a stable and easy-to-make polynuclear unit (Liu, Huang, Huang, Huang, Chen & You, 2009 OR Liu, Huang, Huang, Huang & Chen, 2009 ?; Su et al., 2009; Yao et al., 2009; Liang et al., 2011). In continuation of our interest in the design of coordination polymer frameworks utilizing polynuclear coordination clusters as building units, we present herein a new pillared framework coordination polymer, the title compound, (I), [Cd2(OH)Cl(atz)(isonic)]n.nxH2O, where atz is 5-amino-tetrazolate and isonic is isonicotinate. To the best of our knowledge, (I) represents the first example of three-dimensional coordination polymer framework constructed of Cd2(µ3-OH) belts, i.e. one-dimensional infinitely condensated [Concatenated?] Cd3(µ3-OH) units.
A mixture of Cd(CH3COO)2.3H2O (0.026 g, 0.1 mmol), N-(1H-tetrazol-5yl)isonicotinamide (0.038 g, 0.2 mmol), 0.5 M aqueous ammonia (1 ml) and hydrochloric acid and H2O (6 ml) was stirred for 30 min, sealed in a 23 ml Teflon-lined autoclave and heated in an oven to 393 K for 3 d. After the sample had been cooled to room temperature at a rate of 5 K h-1, colourless block-shaped crystals of (I) were obtained in 34% yield based on Cd.
Crystal data, data collection and structure refinement details are summarized in Table 1. The hydroxy H atom was located in a difference Fourier map and its position and Uiso were refined. The H atoms of the water molecule could not be found in a difference Fourier map due to its low occupancy. The remaining H atoms were refined in idealized positions using the riding-model approximation, with C—H = 0.93 Å and N—H = 0.86 Å, and with Uiso(H) = 1.2Ueq(C,N).
Single-crystal X-ray diffraction study of (I) reveals a three-dimensional coordination framework structure in the monoclinic space group C2/m. The asymmetric unit contains two crystallographically independent CdII cations, Cd1 and Cd2, located on a mirror plane and an inversion centre, respectively. The atz ligand and the isonic anion both reside on the mirror plane and possess Cs symmetry, in spite of their ideal C2v point group symmetry. The Cl- anion, the O atom of the hydroxyl anion and the partly occupied water molecule sit on a mirror plane.
As shown in Fig. 1, the hydroxyl anion in the structure bridges three CdII cations, Cd1 on a mirror plane and two mirror-related Cd2 and Cd2iv [symmetry code: (iv) 1/2 - x, 1/2 + y, 1 - z], to form an OH-centred isosceles triangular Cd3(µ3-OH), with atom O2 deviating by 0.547 (3) Å from the plane of the three CdII cations. In the Cd3(µ3-OH) unit, the Cd1···Cd2 separation is 3.8764 (9) Å and the Cd2···Cd2iv separation is 3.4986 (8) Å. Each edge of the isosceles triangular Cd3(µ3-OH) group is bridged by an atz ligand via a pair N atoms, to form a Cd3(µ3-OH)(atz)3 unit. Since the Cd2 sites are exactly on an inversion centre, the inversion operation brings the Cd3(µ3-OH)(atz)3 unit into a [Cd2(OH)(atz)]n belt extending along a direction (Fig. 2). In the backbone of the belt, the Cd2 atoms are bridged by OH groups to form a zigzag chain, while along both edges of the belt, Cd1 atoms are connected to each other by atz ligands. Every atz ligand bridges two Cd1 and two Cd2 atoms, using all N atoms of its tetrazole ring. The belt is laced with Cl- anions, with a Cd1—Cl1 bond length of 2.5086 (14) Å. The belts are further connected into undulating layers via weak inter-belt Cd—Cl bonds (Fig. 3), with Cd1—Cl1viii = 2.9960 (15) Å.
The construction of the three-dimensional framework of (I) is completed by pillaring with the isonic ligand. The carboxylate O atoms of the isonic ligand coordinate to two mirror-related Cd2 atoms of the Cd3(µ3-OH) core in a syn–syn mode, while the pyridine N atom of the isonic ligand connects to atoms Cd1 in neighbouring layers (Fig. 4). The coordination geometry around both Cd1 and Cd2 atoms can be described as a slightly distorted octahedron. Cd1 is coordinated by a µ3-OH group, two N atoms from two atz units [N2 and N2ii; symmetry code: (ii) x, -y + 1, z], one Cl- anion in the equatorial plane, and one pyridyl N atom [N1i; symmetry code: (i) x + 1/2, y + 1/2, z] of an isonic ligand and one Cl- anion [Cl1viii; symmetry code: (viii) -x, y, -z] in the axial positions. The Cd1—N1i/N2/N2ii distances range from 2.362 (3) to 2.3978 (18) Å, and the Cd1—O2 and Cd1—Cl1 distances are 2.256 (2) and 2.5086 (14) Å, respectively. All these values are in good agreement with those typically observed in related CdII polymeric structures (Yang et al., 2009; Ji et al., 2010). The Cd—Cl1viii distance is 2.9960 (15) Å, which is longer than in the previously reported CdII complex (Liu, Huang, Huang, Huang, Chen & You, 2009 OR Liu, Huang, Huang, Huang & Chen, 2009 ?). The Cd2 cation is equatorially coordinated by two carboxylate O atoms [O1 and O1iii; symmetry code: (iii) -x + 1/2, -y + 1/2, -z + 1] from two isonic groups and two O atoms [O2 and O2vii; symmetry code: (vii) -x + 1/2, y - 1/2, -z + 1] of two µ3-OH groups. The axial positions are occupied by two N atoms (N3, N3iii) from two atz units, with a Cd2—N3 distance of 2.3627 (18) Å, forming an octahedral coordination environment. The Cd2—O distances range from 2.2301 (14) to 2.2832 (17) Å.
The solid-state photoluminescent spectrum of (I) at room temperature is depicted in Fig. 6. The fluorescence spectrum shows that (I) exhibits a broad emission with a maximum wavelength of 447 nm upon excitation at 328 nm. The main chromophore of this compound is the aromatic five-membered ring and its photoluminescence is assigned as originating from π–π* transitions (Liang et al., 2010).
Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear (Rigaku, 2002); data reduction: CrystalClear (Rigaku, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).
[Cd2(CH2N5)Cl(OH)(C6H4NO2)]·0.14H2O | Z = 4 |
Mr = 485.73 | F(000) = 916 |
Monoclinic, C2/m | Dx = 2.426 Mg m−3 |
Hall symbol: -C 2y | Mo Kα radiation, λ = 0.71073 Å |
a = 19.479 (4) Å | µ = 3.41 mm−1 |
b = 6.9971 (14) Å | T = 293 K |
c = 13.235 (3) Å | Block, colourless |
β = 132.52 (3)° | 0.38 × 0.25 × 0.20 mm |
V = 1329.5 (5) Å3 |
Rigaku Saturn 724 CCD area-detector diffractometer | 1648 independent reflections |
Radiation source: fine-focus sealed tube | 1560 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
ω scans | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (RAPID-AUTO; Rigaku, 1998) | h = −25→25 |
Tmin = 0.721, Tmax = 1.000 | k = −8→9 |
6579 measured reflections | l = −17→17 |
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)] = 0.017 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.040 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0159P)2 + 3.1028P] where P = (Fo2 + 2Fc2)/3 |
1648 reflections | (Δ/σ)max = 0.001 |
110 parameters | Δρmax = 0.50 e Å−3 |
0 restraints | Δρmin = −0.71 e Å−3 |
[Cd2(CH2N5)Cl(OH)(C6H4NO2)]·0.14H2O | V = 1329.5 (5) Å3 |
Mr = 485.73 | Z = 4 |
Monoclinic, C2/m | Mo Kα radiation |
a = 19.479 (4) Å | µ = 3.41 mm−1 |
b = 6.9971 (14) Å | T = 293 K |
c = 13.235 (3) Å | 0.38 × 0.25 × 0.20 mm |
β = 132.52 (3)° |
Rigaku Saturn 724 CCD area-detector diffractometer | 1648 independent reflections |
Absorption correction: multi-scan (RAPID-AUTO; Rigaku, 1998) | 1560 reflections with I > 2σ(I) |
Tmin = 0.721, Tmax = 1.000 | Rint = 0.022 |
6579 measured reflections |
R[F2 > 2σ(F2)] = 0.017 | 0 restraints |
wR(F2) = 0.040 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.50 e Å−3 |
1648 reflections | Δρmin = −0.71 e Å−3 |
110 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 | Occ. (<1) | |
Cd1 | 0.142115 (14) | 0.5000 | 0.15898 (2) | 0.01735 (7) | |
Cd2 | 0.2500 | 0.2500 | 0.5000 | 0.01643 (6) | |
Cl1 | 0.03699 (6) | 0.5000 | −0.09699 (8) | 0.03204 (18) | |
O2 | 0.17633 (15) | 0.5000 | 0.3594 (2) | 0.0174 (4) | |
H2O | 0.129 (3) | 0.5000 | 0.336 (4) | 0.034 (12)* | |
O1 | 0.11061 (12) | 0.1600 (3) | 0.4294 (2) | 0.0389 (4) | |
N1 | −0.20907 (18) | 0.0000 | 0.2310 (3) | 0.0275 (6) | |
N2 | 0.14994 (12) | 0.1579 (3) | 0.17296 (17) | 0.0198 (4) | |
N3 | 0.19917 (12) | 0.0920 (2) | 0.30163 (17) | 0.0195 (3) | |
N4 | 0.0706 (2) | 0.0000 | −0.0400 (3) | 0.0362 (7) | |
H4A | 0.0552 | 0.1064 | −0.0832 | 0.043* | 0.50 |
H4B | 0.0540 | −0.1064 | −0.0835 | 0.043* | 0.50 |
C1 | −0.16375 (19) | −0.1605 (4) | 0.2569 (4) | 0.0502 (8) | |
H1 | −0.1944 | −0.2756 | 0.2378 | 0.060* | |
C2 | −0.07356 (19) | −0.1669 (4) | 0.3106 (4) | 0.0477 (8) | |
H2 | −0.0450 | −0.2838 | 0.3264 | 0.057* | |
C3 | −0.0265 (2) | 0.0000 | 0.3404 (3) | 0.0231 (6) | |
C4 | 0.0739 (2) | 0.0000 | 0.4051 (3) | 0.0246 (6) | |
C5 | 0.1208 (2) | 0.0000 | 0.0960 (3) | 0.0184 (5) | |
OW1 | 0.0787 (14) | 0.5000 | 0.524 (2) | 0.039 (7) | 0.142 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.01721 (11) | 0.01260 (11) | 0.01646 (11) | 0.000 | 0.00906 (9) | 0.000 |
Cd2 | 0.01664 (11) | 0.01085 (10) | 0.01597 (10) | −0.00122 (7) | 0.00867 (9) | −0.00030 (7) |
Cl1 | 0.0254 (4) | 0.0358 (4) | 0.0165 (3) | 0.000 | 0.0068 (3) | 0.000 |
O2 | 0.0149 (10) | 0.0151 (10) | 0.0160 (9) | 0.000 | 0.0079 (8) | 0.000 |
O1 | 0.0232 (8) | 0.0355 (10) | 0.0571 (12) | −0.0047 (7) | 0.0268 (9) | −0.0016 (9) |
N1 | 0.0183 (12) | 0.0269 (14) | 0.0360 (15) | 0.000 | 0.0178 (12) | 0.000 |
N2 | 0.0216 (8) | 0.0155 (9) | 0.0184 (8) | −0.0005 (7) | 0.0119 (7) | 0.0011 (7) |
N3 | 0.0246 (9) | 0.0127 (8) | 0.0167 (8) | −0.0004 (7) | 0.0122 (7) | 0.0001 (7) |
N4 | 0.056 (2) | 0.0195 (14) | 0.0204 (14) | 0.000 | 0.0207 (14) | 0.000 |
C1 | 0.0318 (14) | 0.0247 (13) | 0.095 (3) | −0.0053 (11) | 0.0429 (17) | −0.0072 (14) |
C2 | 0.0304 (13) | 0.0265 (13) | 0.089 (2) | 0.0022 (11) | 0.0417 (16) | −0.0002 (14) |
C3 | 0.0160 (13) | 0.0295 (16) | 0.0253 (15) | 0.000 | 0.0145 (12) | 0.000 |
C4 | 0.0166 (14) | 0.0336 (17) | 0.0236 (15) | 0.000 | 0.0136 (13) | 0.000 |
C5 | 0.0200 (13) | 0.0163 (13) | 0.0164 (13) | 0.000 | 0.0113 (12) | 0.000 |
OW1 | 0.049 (13) | 0.020 (9) | 0.070 (15) | 0.000 | 0.049 (12) | 0.000 |
Cd1—O2 | 2.256 (2) | N1—Cd1vi | 2.362 (3) |
Cd1—N1i | 2.362 (3) | N2—C5 | 1.341 (2) |
Cd1—N2ii | 2.3978 (18) | N2—N3 | 1.351 (2) |
Cd1—N2 | 2.3978 (18) | N3—N3v | 1.287 (3) |
Cd1—Cl1 | 2.5086 (14) | N4—C5 | 1.348 (4) |
Cd2—O2iii | 2.2301 (14) | N4—H4A | 0.8600 |
Cd2—O2 | 2.2301 (14) | N4—H4B | 0.8600 |
Cd2—O1 | 2.2832 (17) | C1—C2 | 1.380 (3) |
Cd2—O1iii | 2.2832 (17) | C1—H1 | 0.9300 |
Cd2—N3iii | 2.3627 (18) | C2—C3 | 1.367 (3) |
Cd2—N3 | 2.3627 (18) | C2—H2 | 0.9300 |
O2—Cd2iv | 2.2301 (14) | C3—C2v | 1.367 (3) |
O2—H2O | 0.75 (4) | C3—C4 | 1.515 (4) |
O1—C4 | 1.248 (2) | C4—O1v | 1.248 (2) |
N1—C1v | 1.322 (3) | C5—N2v | 1.341 (2) |
N1—C1 | 1.322 (3) | ||
O2—Cd1—N1i | 102.65 (10) | Cd1—O2—H2O | 102 (3) |
O2—Cd1—N2ii | 87.50 (4) | C4—O1—Cd2 | 131.97 (17) |
N1i—Cd1—N2ii | 88.41 (4) | C1v—N1—C1 | 116.3 (3) |
O2—Cd1—N2 | 87.50 (4) | C1v—N1—Cd1vi | 121.79 (15) |
N1i—Cd1—N2 | 88.41 (4) | C1—N1—Cd1vi | 121.79 (15) |
N2ii—Cd1—N2 | 173.35 (8) | C5—N2—N3 | 104.56 (17) |
O2—Cd1—Cl1 | 155.59 (6) | C5—N2—Cd1 | 142.34 (14) |
N1i—Cd1—Cl1 | 101.76 (8) | N3—N2—Cd1 | 113.09 (12) |
N2ii—Cd1—Cl1 | 93.18 (4) | N3v—N3—N2 | 109.97 (11) |
N2—Cd1—Cl1 | 93.18 (4) | N3v—N3—Cd2 | 117.91 (4) |
O2iii—Cd2—O2 | 180.0 | N2—N3—Cd2 | 130.41 (13) |
O2iii—Cd2—O1 | 92.39 (8) | C5—N4—H4A | 120.0 |
O2—Cd2—O1 | 87.61 (8) | C5—N4—H4B | 120.0 |
O2iii—Cd2—O1iii | 87.61 (8) | H4A—N4—H4B | 120.0 |
O2—Cd2—O1iii | 92.39 (8) | N1—C1—C2 | 123.7 (3) |
O1—Cd2—O1iii | 180.00 (10) | N1—C1—H1 | 118.1 |
O2iii—Cd2—N3iii | 83.66 (6) | C2—C1—H1 | 118.1 |
O2—Cd2—N3iii | 96.34 (6) | C3—C2—C1 | 119.5 (2) |
O1—Cd2—N3iii | 94.18 (7) | C3—C2—H2 | 120.3 |
O1iii—Cd2—N3iii | 85.82 (7) | C1—C2—H2 | 120.3 |
O2iii—Cd2—N3 | 96.34 (6) | C2—C3—C2v | 117.3 (3) |
O2—Cd2—N3 | 83.66 (6) | C2—C3—C4 | 121.35 (15) |
O1—Cd2—N3 | 85.82 (7) | C2v—C3—C4 | 121.35 (15) |
O1iii—Cd2—N3 | 94.18 (7) | O1—C4—O1v | 127.6 (3) |
N3iii—Cd2—N3 | 180.0 | O1—C4—C3 | 116.22 (15) |
Cd2iv—O2—Cd2 | 103.33 (9) | O1v—C4—C3 | 116.22 (15) |
Cd2iv—O2—Cd1 | 119.57 (6) | N2—C5—N2v | 110.9 (2) |
Cd2—O2—Cd1 | 119.57 (6) | N2—C5—N4 | 124.53 (12) |
Cd2iv—O2—H2O | 105.2 (19) | N2v—C5—N4 | 124.53 (12) |
Cd2—O2—H2O | 105.2 (19) |
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x, −y+1, z; (iii) −x+1/2, −y+1/2, −z+1; (iv) −x+1/2, y+1/2, −z+1; (v) x, −y, z; (vi) x−1/2, y−1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Cd2(CH2N5)Cl(OH)(C6H4NO2)]·0.14H2O |
Mr | 485.73 |
Crystal system, space group | Monoclinic, C2/m |
Temperature (K) | 293 |
a, b, c (Å) | 19.479 (4), 6.9971 (14), 13.235 (3) |
β (°) | 132.52 (3) |
V (Å3) | 1329.5 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.41 |
Crystal size (mm) | 0.38 × 0.25 × 0.20 |
Data collection | |
Diffractometer | Rigaku Saturn 724 CCD area-detector diffractometer |
Absorption correction | Multi-scan (RAPID-AUTO; Rigaku, 1998) |
Tmin, Tmax | 0.721, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6579, 1648, 1560 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.017, 0.040, 1.06 |
No. of reflections | 1648 |
No. of parameters | 110 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.50, −0.71 |
Computer programs: CrystalClear (Rigaku, 2002), SHELXS97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2004), SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).