Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229615015156/yo3012sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S2053229615015156/yo3012Isup2.hkl | |
Microsoft Word (DOC) file https://doi.org/10.1107/S2053229615015156/yo3012Isup3.doc | |
Microsoft Word (DOC) file https://doi.org/10.1107/S2053229615015156/yo3012Isup4.doc |
CCDC reference: 1418674
\ Recently, the design and synthesis of polymeric coordination networks have attracted intensive attention, not only owing to their intriguing architectures, but also due to their unique chemical and physical properties for potential applications (Moulton & Zaworotko, 2001; Gao et al., 2008). There are reports in which N- and S-donor bridging ligands have been used to form infinite polymeric frameworks (Kuniyasu et al., 1987; Liu et al., 2002; Zhang et al., 1999). The anionic thiocyanate ligand (SCN-) is a highly versatile ambidentate ligand with a polarizable π-system and it can coordinate to metal ions through either/both the N or/and the S atom (Eichele & Wasylishen, 1994). Different bridging modes of the thiocyanate ligand and the CdII cation can generate various types of dimensional structures with particular properties, such as nonlinear optical behaviour (Liu et al., 2002). Furthermore, due to the general lability of CdII complexes, the formation of coordination bonds is reversible, which enables metal ions and ligands to rearrange during the process of polymerization to give highly ordered network structures (Shahverdizadeh & Morsali, 2011).
Most of the reported framework structures of polymeric cadmium complexes are linear polymeric chains having double thiocyanate bridges, with two-dimensional networks being quite rare. Recently, however, a particularly interesting two-dimensional honeycomb-like {[Cd(NCS)]-}n anionic polymeric framework, in which the Cd—NCS—Cd units link to form eight-membered rings, was observed (Lai et al., 2007). Furthermore, the structure of a [Cd(SCN)2(dmen)]n (dmen is N,N-dimethylethylenediamine) complex, composed of eight-membered (Cd—NCS—Cd links) and five-membered rings (C—N—Cd—N—C links) combining to form a novel two-dimensional polymeric sheet, was reported (Mondal et al., 2000). In the present paper, we report the use of nicotinic acid as a template for the formation of a new two-dimensional coordination polymer, which is assembled by [Cd(SCN)2] and nitrogen [nicotinic acid? nitrogen-containing?] ligands, namely poly[[bis(nicotinic acid-κN)di-µ-thiocyanato-κ2N:S;κ2S:\ N-cadmium(II)] monohydrate], (I).
The title compound was obtained from an aqueous solution containing 1:1:3 molar equivalents of nicotinic acid, cadmium nitrate tetrahydrate and potassium thiocyanide. The resulting aqueous solution was kept at room temperature. Upon standing at room temperature for several days, suitable colourless single crystals of (I) were obtained by slow solvent evaporation.
Crystal data, data collection and structure refinement details are summarized in Table 1. C-bound H atoms were included in calculated positions and refined using a riding model, with C—H = 0.93 Å and Uiso (H) = 1.2Ueq(C). The water H atoms were located in a difference Fourier synthesis and refined isotropically, with O—H and H···H distance restraints of 0.82 (1) and 1.39 (1) Å, respectively.
\ Compound (I) crystallizes in the monoclinic space group C2/c. The independent unit is composed of one CdII cation, two nicotinic acid ligands, two anionic thiocyanate (SCN-) ligands and one free water molecule (Fig. 1).
As shown in Fig. 2, the central CdII cation is six-coordinated by two N atoms from two nicotinic acid ligands, and by two N atoms and two S atoms from four different SCN- ligands, adopting a distorted CdN4S2 octahedral coordinated geometry. Each of the central CdII cations is joined to the neighbouring CdII cations through a single thiocyanate bridge. The Cd—N [2.321 (3)–2.352 (2) Å] and Cd—S [2.7550 (12) Å] distances are typical for Cd—N and Cd—S bonds (Gao et al., 2008; Wei et al., 2007). There are two sorts of angles around each CdII centre, namely orthogonal cis angles [88.49 (7)–91.51 (7)°] and linear trans angles (180°). In general, all the bond lengths and angles are within normal ranges, similar to those in other cadmium–thiocyanate compounds. The Cd—S—C and Cd—N—C bond angles are consistent with those of other reported cadmium–thiocyanate compounds (Wang et al., 2004; Liu et al., 2002).
Compound (I) is a new coordination polymer in which the six-coordinated CdII centre adopts a distorted octahedral coordination geometry. It displays a different coordination architecture compared with the similar compound, {[Cd3(NCS)2(3-pyc)4(H2O)4].2H2O}n (Shahverdizadeh & Morsali, 2011; 3-Hpyc is pyridine-3-carboxylic acid), in which the central Cd2 cation is coordinated by two O atoms from two water molecules, two N atoms from nicotinic acid ligands and two N atoms from thiocyanate ligands, rather than two N atoms of nicotinic acid ligands, plus the two N atoms and two S atoms of four different thiocyanate ligands.
The two-dimensional network of (I) is a new coordination architecture compared with the related structure [Cd(SCN)2(pyCN)2] (pyCN is isonicotinonitrile; Chen et al., 2002), where there is a one-dimensional infinite linear chain structure consisting of eight-membered rings of two CdII cations and two bridging SCN- ligands. As with (I), the CdII cations are linked by the N atoms of nicotinic acid, two N:S-bridging and two S:N-bridging thiocyanate ligands, forming an infinite two-dimensional coordination polymer, which we shall refer to as a two-dimensional puckered rectangular network (Fig. 2). This is different from what we found in our previous report on catena-poly[1-carboxymethyl-4-(dimethylamino)pyridinium [cadmium(II)-tri-µ-thiocyanato-κ4N:S;κ2S:N] [[[4-(dimethylamino)pyridinium-1-acetate-κ2O,O']cadmium(II)]\ di-µ-thiocyanato-κ2N:S;κ2S:N]] (Wang & Zhou, 2015), where the Cd1 atoms are chelated by a carboxylate group of a 4-(dimethylamino)pyridinium-1-acetate ligand and linked by two N:S-bridging and two S:N-bridging thiocyanate ligands, forming an infinite one-dimensional puckered coordination polymer. The CdII cations are alternately connected in one direction by M(NCS)M bridges, and in the other direction also by a single thiocyanate bridge to form a two-dimensional network, with a Cd···Cd distance of 6.2247 (9) Å in the bc plane. In (I), the corrugated two-dimensional net structure has a puckered rectangular net structure where each loop within the grid is composed of a Cd4(NCS)4 ring, with four coordinated ligands in total per grid in the bc plane (Fig. 2). This also differs from the two-dimensional polymeric sheet of [Cd(SCN)2(dmen)]n (Mondal et al., 2000; dmen is N,N-dimethylethylenediamine), which is formed through the bidentate dmen ligand and single SCN- bridges. It should be pointed out that the bidentate dmen molecule coordinates to a CdII cation in a cis position, which is different from (I), where two monodentate nicotinic acid molecules coordinate in trans positions.
As well as the coordination polymer, (I) also contains uncoordinated solvent water molecules. Each water molecule and carboxylic acid group are connected to two adjacent coordination polymers by means of O1W—H1W···O2 and O1—H1A···O2 hydrogen bonds (Fig. 3 and Table 2). Thus, each carboxylic acid group takes part in two hydrogen bonds, with the hydrogen bond linking the water to the nicotinic acid. These electrostatic and hydrogen-bonding interactions link the polymeric chains together, where the gaps between the chains are filled by the water molecules (Fig. 4). The O—H···O hydrogen-bonding interactions serve again as important driving forces to crosslink the puckered two-dimensional networks into a three-dimensional architecture in the ac plane (Fig. 4). Intermolecular hydrogen-bonding interactions between the nicotinic acid ligands and the uncoordinated water molecules further stabilize the corrugated three-dimensional network.
In summary, a new cadmium–thiocyanate coordination polymer with an interesting structural architecture has been prepared. The CdII cations are linked by N atoms from the nicotinic acid ligands and by bridging thiocyanate ligands to form a two-dimensional coordination polymer which lies parallel to the bc plane. Hydrogen-bond interactions between the uncoordinated solvent water molecules and the organic ligands are involved in the formation of the three-dimensional architecture.
Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
[Cd(NCS)2(C6H5NO2)2]·H2O | F(000) = 976 |
Mr = 492.80 | Dx = 1.807 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 2070 reflections |
a = 24.174 (5) Å | θ = 3.3–27.5° |
b = 9.850 (2) Å | µ = 1.47 mm−1 |
c = 7.6135 (15) Å | T = 293 K |
β = 92.44 (3)° | Block, colourless |
V = 1811.2 (6) Å3 | 0.28 × 0.25 × 0.20 mm |
Z = 4 |
Rigaku SCXmini diffractometer | 1794 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Graphite monochromator | θmax = 27.5°, θmin = 3.3° |
ω scans | h = −31→31 |
Absorption correction: multi-scan ? | k = −12→11 |
Tmin = 0.684, Tmax = 0.758 | l = −9→7 |
6122 measured reflections | 3 standard reflections every 180 reflections |
2070 independent reflections | intensity decay: none |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.030 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.085 | w = 1/[σ2(Fo2) + (0.050P)2 + 3.P] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max < 0.001 |
2070 reflections | Δρmax = 0.44 e Å−3 |
126 parameters | Δρmin = −0.47 e Å−3 |
3 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008) |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0819 (12) |
[Cd(NCS)2(C6H5NO2)2]·H2O | V = 1811.2 (6) Å3 |
Mr = 492.80 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 24.174 (5) Å | µ = 1.47 mm−1 |
b = 9.850 (2) Å | T = 293 K |
c = 7.6135 (15) Å | 0.28 × 0.25 × 0.20 mm |
β = 92.44 (3)° |
Rigaku SCXmini diffractometer | 1794 reflections with I > 2σ(I) |
Absorption correction: multi-scan ? | Rint = 0.025 |
Tmin = 0.684, Tmax = 0.758 | 3 standard reflections every 180 reflections |
6122 measured reflections | intensity decay: none |
2070 independent reflections |
R[F2 > 2σ(F2)] = 0.030 | 3 restraints |
wR(F2) = 0.085 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.44 e Å−3 |
2070 reflections | Δρmin = −0.47 e Å−3 |
126 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 | ||
Cd1 | 0.2500 | 0.2500 | 1.0000 | 0.02973 (12) | |
S1 | 0.31494 (4) | 0.70616 (9) | 0.80081 (12) | 0.0435 (2) | |
O1 | 0.43099 (13) | 0.4946 (4) | 0.6234 (5) | 0.0754 (9) | |
H1A | 0.4511 (18) | 0.553 (4) | 0.578 (6) | 0.090* | |
O2 | 0.48551 (11) | 0.3293 (3) | 0.5279 (4) | 0.0601 (7) | |
N1 | 0.33088 (10) | 0.1962 (3) | 0.8535 (3) | 0.0319 (5) | |
N2 | 0.26096 (12) | 0.4774 (3) | 0.9296 (4) | 0.0409 (6) | |
C1 | 0.36200 (13) | 0.2910 (4) | 0.7766 (4) | 0.0352 (6) | |
H1B | 0.3506 | 0.3811 | 0.7806 | 0.042* | |
C2 | 0.40952 (13) | 0.2612 (3) | 0.6928 (4) | 0.0349 (7) | |
C3 | 0.42573 (14) | 0.1251 (4) | 0.6869 (5) | 0.0434 (8) | |
H3 | 0.4576 | 0.1004 | 0.6308 | 0.052* | |
C4 | 0.39424 (15) | 0.0288 (4) | 0.7642 (5) | 0.0469 (8) | |
H4 | 0.4045 | −0.0621 | 0.7617 | 0.056* | |
C5 | 0.34731 (13) | 0.0679 (3) | 0.8459 (4) | 0.0386 (7) | |
H5 | 0.3261 | 0.0015 | 0.8980 | 0.046* | |
C6 | 0.44482 (13) | 0.3656 (4) | 0.6082 (5) | 0.0428 (8) | |
C7 | 0.28255 (12) | 0.5729 (3) | 0.8770 (4) | 0.0302 (6) | |
O1W | 0.5000 | 0.1570 (6) | 0.2500 | 0.127 (2) | |
H1W | 0.486 (4) | 0.205 (2) | 0.328 (8) | 0.191* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.03461 (18) | 0.02221 (17) | 0.03330 (19) | −0.00492 (11) | 0.01249 (12) | 0.00013 (11) |
S1 | 0.0516 (5) | 0.0345 (4) | 0.0436 (5) | −0.0168 (4) | −0.0062 (4) | 0.0131 (4) |
O1 | 0.0660 (19) | 0.069 (2) | 0.093 (3) | −0.0151 (16) | 0.0246 (17) | 0.0188 (18) |
O2 | 0.0486 (15) | 0.0675 (19) | 0.0669 (18) | −0.0031 (13) | 0.0311 (13) | 0.0123 (14) |
N1 | 0.0329 (13) | 0.0321 (13) | 0.0314 (13) | −0.0069 (10) | 0.0097 (10) | −0.0007 (11) |
N2 | 0.0494 (15) | 0.0290 (14) | 0.0449 (16) | −0.0045 (12) | 0.0111 (12) | 0.0073 (12) |
C1 | 0.0388 (16) | 0.0304 (14) | 0.0369 (17) | −0.0061 (13) | 0.0085 (13) | 0.0009 (13) |
C2 | 0.0302 (14) | 0.0432 (19) | 0.0315 (16) | −0.0064 (12) | 0.0039 (12) | 0.0025 (12) |
C3 | 0.0340 (16) | 0.052 (2) | 0.045 (2) | 0.0018 (14) | 0.0119 (14) | −0.0029 (16) |
C4 | 0.0459 (18) | 0.0365 (18) | 0.059 (2) | 0.0013 (15) | 0.0122 (16) | −0.0032 (16) |
C5 | 0.0396 (16) | 0.0328 (16) | 0.0441 (18) | −0.0085 (13) | 0.0103 (13) | 0.0015 (14) |
C6 | 0.0328 (15) | 0.054 (2) | 0.0425 (19) | −0.0094 (14) | 0.0082 (13) | 0.0100 (15) |
C7 | 0.0365 (15) | 0.0269 (14) | 0.0271 (14) | 0.0004 (11) | 0.0016 (11) | 0.0027 (11) |
O1W | 0.149 (6) | 0.081 (4) | 0.157 (7) | 0.000 | 0.067 (5) | 0.000 |
Cd1—N2i | 2.321 (3) | N1—C1 | 1.349 (4) |
Cd1—N2 | 2.321 (3) | N2—C7 | 1.155 (4) |
Cd1—N1i | 2.352 (2) | C1—C2 | 1.369 (4) |
Cd1—N1 | 2.352 (2) | C1—H1B | 0.9300 |
Cd1—S1ii | 2.7550 (12) | C2—C3 | 1.398 (5) |
Cd1—S1iii | 2.7550 (12) | C2—C6 | 1.499 (4) |
S1—C7 | 1.646 (3) | C3—C4 | 1.365 (5) |
S1—Cd1iv | 2.7550 (12) | C3—H3 | 0.9299 |
O1—C6 | 1.321 (5) | C4—C5 | 1.372 (5) |
O1—H1A | 0.835 (10) | C4—H4 | 0.9301 |
O2—C6 | 1.233 (4) | C5—H5 | 0.9300 |
N1—C5 | 1.327 (4) | O1W—H1W | 0.840 (10) |
N2i—Cd1—N2 | 180.0 | C7—N2—Cd1 | 157.4 (3) |
N2i—Cd1—N1i | 90.16 (10) | N1—C1—C2 | 123.2 (3) |
N2—Cd1—N1i | 89.84 (10) | N1—C1—H1B | 118.4 |
N2i—Cd1—N1 | 89.84 (10) | C2—C1—H1B | 118.4 |
N2—Cd1—N1 | 90.16 (10) | C1—C2—C3 | 117.5 (3) |
N1i—Cd1—N1 | 180.0 | C1—C2—C6 | 123.9 (3) |
N2i—Cd1—S1ii | 88.52 (8) | C3—C2—C6 | 118.6 (3) |
N2—Cd1—S1ii | 91.48 (7) | C4—C3—C2 | 119.3 (3) |
N1i—Cd1—S1ii | 88.49 (7) | C4—C3—H3 | 120.3 |
N1—Cd1—S1ii | 91.51 (7) | C2—C3—H3 | 120.3 |
N2i—Cd1—S1iii | 91.48 (8) | C3—C4—C5 | 119.2 (3) |
N2—Cd1—S1iii | 88.52 (7) | C3—C4—H4 | 120.4 |
N1i—Cd1—S1iii | 91.51 (7) | C5—C4—H4 | 120.4 |
N1—Cd1—S1iii | 88.49 (7) | N1—C5—C4 | 122.8 (3) |
S1ii—Cd1—S1iii | 180.0 | N1—C5—H5 | 118.6 |
C7—S1—Cd1iv | 98.93 (10) | C4—C5—H5 | 118.6 |
C6—O1—H1A | 118 (4) | O2—C6—O1 | 122.2 (3) |
C5—N1—C1 | 117.9 (3) | O2—C6—C2 | 119.7 (3) |
C5—N1—Cd1 | 119.5 (2) | O1—C6—C2 | 118.1 (3) |
C1—N1—Cd1 | 122.7 (2) | N2—C7—S1 | 178.3 (3) |
N2i—Cd1—N1—C5 | 1.0 (2) | Cd1—N1—C1—C2 | 179.2 (2) |
N2—Cd1—N1—C5 | −179.0 (2) | N1—C1—C2—C3 | 0.5 (5) |
N1i—Cd1—N1—C5 | 145 (100) | N1—C1—C2—C6 | −179.4 (3) |
S1ii—Cd1—N1—C5 | −87.5 (2) | C1—C2—C3—C4 | −0.3 (5) |
S1iii—Cd1—N1—C5 | 92.5 (2) | C6—C2—C3—C4 | 179.6 (3) |
N2i—Cd1—N1—C1 | −178.6 (2) | C2—C3—C4—C5 | 0.1 (6) |
N2—Cd1—N1—C1 | 1.4 (2) | C1—N1—C5—C4 | 0.2 (5) |
N1i—Cd1—N1—C1 | −34 (100) | Cd1—N1—C5—C4 | −179.4 (3) |
S1ii—Cd1—N1—C1 | 92.8 (2) | C3—C4—C5—N1 | 0.0 (6) |
S1iii—Cd1—N1—C1 | −87.2 (2) | C1—C2—C6—O2 | −176.4 (3) |
N2i—Cd1—N2—C7 | −178 (100) | C3—C2—C6—O2 | 3.7 (5) |
N1i—Cd1—N2—C7 | 171.7 (7) | C1—C2—C6—O1 | 3.8 (5) |
N1—Cd1—N2—C7 | −8.3 (7) | C3—C2—C6—O1 | −176.1 (3) |
S1ii—Cd1—N2—C7 | −99.8 (7) | Cd1—N2—C7—S1 | −1 (11) |
S1iii—Cd1—N2—C7 | 80.2 (7) | Cd1iv—S1—C7—N2 | 111 (10) |
C5—N1—C1—C2 | −0.5 (5) |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+2; (ii) −x+1/2, y−1/2, −z+3/2; (iii) x, −y+1, z+1/2; (iv) −x+1/2, y+1/2, −z+3/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O2v | 0.84 (1) | 2.11 (2) | 2.934 (4) | 169 (5) |
O1W—H1W···O2 | 0.84 (1) | 1.96 (5) | 2.746 (5) | 156 (11) |
Symmetry code: (v) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Cd(NCS)2(C6H5NO2)2]·H2O |
Mr | 492.80 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 24.174 (5), 9.850 (2), 7.6135 (15) |
β (°) | 92.44 (3) |
V (Å3) | 1811.2 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.47 |
Crystal size (mm) | 0.28 × 0.25 × 0.20 |
Data collection | |
Diffractometer | Rigaku SCXmini diffractometer |
Absorption correction | Multi-scan |
Tmin, Tmax | 0.684, 0.758 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6122, 2070, 1794 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.085, 1.01 |
No. of reflections | 2070 |
No. of parameters | 126 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.44, −0.47 |
Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O2i | 0.835 (10) | 2.111 (15) | 2.934 (4) | 169 (5) |
O1W—H1W···O2 | 0.840 (10) | 1.96 (5) | 2.746 (5) | 156 (11) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
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