Buy article online - an online subscription or single-article purchase is required to access this article.
The title complex, [CdNi(CN)4(C6H7N)2]n, adopts a slightly distorted octahedral geometry around the Cd centre. Four cyanide N atoms occupy the equatorial coordination sites around the Cd centre. The structure consists of corrugated and cyanide-bridged polymeric networks made up of tetracyanonickelate ions coordinated to cadmium, with the Ni ion coordinated by four cyanide ligands in a square-planar arrangement. The Cd and Ni atoms occupy special positions of 2/m site symmetry. The 3-methylpyridine group, except for two methyl H atoms, lies on a crystallographic mirror plane. The 3-methylpyridine molecules, bound to cadmium in trans positions, are located on both sides of the network. The bonding in the networks occurs because of a departure of the Ni—C—N—Cd sequence of atoms from linearity at the C and N atoms.
Supporting information
CCDC reference: 268076
The synthesis of the title compound and its characterization by IR spectroscopy have been described previously by Akyüz et al. (1994). Crystals of (I) were obtained from a solution in which solvent?
H atoms were treated as riding atoms, with C—H distances of 0.93 Å for aromatic H atoms and 0.96 Å for methyl H atoms, and with Uiso(H) = 1.5Ueq(C). Please check added text. Also, some H atoms have s.u.s in the CIF.
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1993); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
poly[[bis(3-methylpyridine)cadmium(II)]-tetra-µ-cyano-nickel(II)]
top
Crystal data top
[CdNi(CN)4(C6H7N)2] | F(000) = 456 |
Mr = 461.44 | Dx = 1.730 Mg m−3 |
Monoclinic, C2/m | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2y | Cell parameters from 25 reflections |
a = 16.5198 (16) Å | θ = 10.6–18.7° |
b = 7.3512 (7) Å | µ = 2.27 mm−1 |
c = 7.6309 (6) Å | T = 293 K |
β = 107.06 (1)° | Prismatic, orange |
V = 885.92 (14) Å3 | 0.42 × 0.36 × 0.24 mm |
Z = 2 | |
Data collection top
Enraf-Nonius CAD-4 diffractometer | 937 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Graphite monochromator | θmax = 26.3°, θmin = 2.6° |
ω/2θ scans | h = −20→20 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→9 |
Tmin = 0.427, Tmax = 0.580 | l = −9→9 |
1793 measured reflections | 3 standard reflections every 120 min |
972 independent reflections | intensity decay: 2.5% |
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)] = 0.028 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.084 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0623P)2 + 0.7317P] where P = (Fo2 + 2Fc2)/3 |
972 reflections | (Δ/σ)max < 0.001 |
73 parameters | Δρmax = 1.40 e Å−3 |
0 restraints | Δρmin = −0.60 e Å−3 |
Crystal data top
[CdNi(CN)4(C6H7N)2] | V = 885.92 (14) Å3 |
Mr = 461.44 | Z = 2 |
Monoclinic, C2/m | Mo Kα radiation |
a = 16.5198 (16) Å | µ = 2.27 mm−1 |
b = 7.3512 (7) Å | T = 293 K |
c = 7.6309 (6) Å | 0.42 × 0.36 × 0.24 mm |
β = 107.06 (1)° | |
Data collection top
Enraf-Nonius CAD-4 diffractometer | 937 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.025 |
Tmin = 0.427, Tmax = 0.580 | 3 standard reflections every 120 min |
1793 measured reflections | intensity decay: 2.5% |
972 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.028 | 0 restraints |
wR(F2) = 0.084 | H-atom parameters constrained |
S = 1.07 | Δρmax = 1.40 e Å−3 |
972 reflections | Δρmin = −0.60 e Å−3 |
73 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 | Occ. (<1) |
Cd1 | 0.0000 | 0.0000 | 0.0000 | 0.02228 (18) | |
Ni1 | 0.0000 | 0.5000 | −0.5000 | 0.0199 (2) | |
N1 | −0.14144 (19) | 0.0000 | −0.0069 (4) | 0.0326 (6) | |
N2 | −0.02489 (17) | 0.2183 (3) | −0.2346 (3) | 0.0393 (5) | |
C1 | −0.2023 (3) | 0.0000 | −0.1650 (6) | 0.0484 (10) | |
H1 | −0.1875 | 0.0000 | −0.2736 | 0.046 (16)* | |
C2 | −0.2868 (3) | 0.0000 | −0.1739 (7) | 0.0628 (14) | |
H2 | −0.3282 | 0.0000 | −0.2869 | 0.09 (2)* | |
C3 | −0.3095 (3) | 0.0000 | −0.0147 (7) | 0.0516 (11) | |
H3 | −0.3664 | 0.0000 | −0.0188 | 0.09 (2)* | |
C4 | −0.2478 (3) | 0.0000 | 0.1496 (8) | 0.0405 (11) | |
C5 | −0.1641 (2) | 0.0000 | 0.1464 (5) | 0.0378 (8) | |
H5 | −0.1215 | 0.0000 | 0.2577 | 0.051 (13)* | |
C6 | −0.2670 (4) | 0.0000 | 0.3295 (10) | 0.072 (2) | |
H6A | −0.2150 | 0.0000 | 0.4277 | 0.109* | |
H6B | −0.2992 | −0.1066 | 0.3381 | 0.109* | 0.50 |
H6C | −0.2992 | 0.1066 | 0.3381 | 0.109* | 0.50 |
C7 | −0.01635 (16) | 0.3228 (3) | −0.3393 (3) | 0.0265 (5) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cd1 | 0.0332 (3) | 0.0169 (2) | 0.0209 (2) | 0.000 | 0.01449 (17) | 0.000 |
Ni1 | 0.0299 (4) | 0.0146 (3) | 0.0174 (3) | 0.000 | 0.0105 (3) | 0.000 |
N1 | 0.0357 (15) | 0.0353 (16) | 0.0289 (14) | 0.000 | 0.0126 (12) | 0.000 |
N2 | 0.0541 (14) | 0.0308 (12) | 0.0379 (12) | 0.0023 (11) | 0.0213 (11) | 0.0095 (11) |
C1 | 0.046 (2) | 0.068 (3) | 0.0303 (18) | 0.000 | 0.0099 (17) | 0.000 |
C2 | 0.040 (2) | 0.093 (4) | 0.045 (2) | 0.000 | −0.003 (2) | 0.000 |
C3 | 0.0312 (19) | 0.061 (3) | 0.062 (3) | 0.000 | 0.0129 (19) | 0.000 |
C4 | 0.039 (2) | 0.040 (2) | 0.049 (3) | 0.000 | 0.023 (2) | 0.000 |
C5 | 0.0356 (19) | 0.049 (2) | 0.0316 (17) | 0.000 | 0.0148 (15) | 0.000 |
C6 | 0.058 (4) | 0.108 (6) | 0.067 (4) | 0.000 | 0.043 (3) | 0.000 |
C7 | 0.0356 (12) | 0.0209 (11) | 0.0252 (10) | 0.0022 (9) | 0.0123 (9) | 0.0007 (9) |
Geometric parameters (Å, º) top
Cd1—N1 | 2.322 (3) | C1—C2 | 1.378 (7) |
Cd1—N1i | 2.322 (3) | C1—H1 | 0.9300 |
Cd1—N2ii | 2.349 (2) | C2—C3 | 1.373 (7) |
Cd1—N2iii | 2.349 (2) | C2—H2 | 0.9300 |
Cd1—N2i | 2.349 (2) | C3—C4 | 1.365 (8) |
Cd1—N2 | 2.349 (2) | C3—H3 | 0.9300 |
Ni1—C7iv | 1.863 (2) | C4—C5 | 1.390 (6) |
Ni1—C7v | 1.863 (2) | C4—C6 | 1.497 (11) |
Ni1—C7 | 1.863 (2) | C5—H5 | 0.9301 |
Ni1—C7vi | 1.863 (2) | C6—H6A | 0.9600 |
N1—C1 | 1.324 (5) | C6—H6B | 0.9600 |
N1—C5 | 1.329 (5) | C6—H6C | 0.9600 |
N2—C7 | 1.146 (3) | | |
| | | |
N1—Cd1—N1i | 180.0 | C7—N2—Cd1 | 163.5 (2) |
N1—Cd1—N2ii | 91.87 (8) | N1—C1—C2 | 122.2 (4) |
N1i—Cd1—N2ii | 88.13 (8) | N1—C1—H1 | 118.9 |
N1—Cd1—N2iii | 88.13 (8) | C2—C1—H1 | 118.9 |
N1i—Cd1—N2iii | 91.87 (8) | C3—C2—C1 | 119.5 (4) |
N2ii—Cd1—N2iii | 180.00 (8) | C3—C2—H2 | 120.2 |
N1—Cd1—N2i | 88.13 (8) | C1—C2—H2 | 120.3 |
N1i—Cd1—N2i | 91.87 (8) | C4—C3—C2 | 119.3 (4) |
N2ii—Cd1—N2i | 93.82 (12) | C4—C3—H3 | 120.4 |
N2iii—Cd1—N2i | 86.18 (12) | C2—C3—H3 | 120.4 |
N1—Cd1—N2 | 91.87 (8) | C3—C4—C5 | 117.6 (5) |
N1i—Cd1—N2 | 88.13 (8) | C3—C4—C6 | 122.7 (6) |
N2ii—Cd1—N2 | 86.18 (12) | C5—C4—C6 | 119.7 (6) |
N2iii—Cd1—N2 | 93.82 (12) | N1—C5—C4 | 123.6 (4) |
N2i—Cd1—N2 | 180.0 | N1—C5—H5 | 118.2 |
C7iv—Ni1—C7v | 180.00 (15) | C4—C5—H5 | 118.2 |
C7iv—Ni1—C7 | 88.77 (13) | C4—C6—H6A | 109.5 |
C7v—Ni1—C7 | 91.23 (13) | C4—C6—H6B | 109.5 |
C7iv—Ni1—C7vi | 91.23 (13) | H6A—C6—H6B | 109.5 |
C7v—Ni1—C7vi | 88.77 (13) | C4—C6—H6C | 109.5 |
C7—Ni1—C7vi | 180.00 (15) | H6A—C6—H6C | 109.5 |
C1—N1—C5 | 117.9 (3) | H6B—C6—H6C | 109.5 |
C1—N1—Cd1 | 120.7 (3) | N2—C7—Ni1 | 177.2 (2) |
C5—N1—Cd1 | 121.4 (2) | | |
| | | |
N2ii—Cd1—N1—C1 | −43.12 (6) | N2iii—Cd1—N2—C7 | 85.9 (7) |
N2iii—Cd1—N1—C1 | 136.88 (6) | C5—N1—C1—C2 | 0.0 |
N2i—Cd1—N1—C1 | −136.88 (6) | Cd1—N1—C1—C2 | 180.0 |
N2—Cd1—N1—C1 | 43.12 (6) | N1—C1—C2—C3 | 0.0 |
N2ii—Cd1—N1—C5 | 136.88 (6) | C1—C2—C3—C4 | 0.0 |
N2iii—Cd1—N1—C5 | −43.12 (6) | C2—C3—C4—C5 | 0.0 |
N2i—Cd1—N1—C5 | 43.12 (6) | C2—C3—C4—C6 | 180.0 |
N2—Cd1—N1—C5 | −136.88 (6) | C1—N1—C5—C4 | 0.0 |
N1—Cd1—N2—C7 | 174.1 (7) | Cd1—N1—C5—C4 | 180.0 |
N1i—Cd1—N2—C7 | −5.9 (7) | C3—C4—C5—N1 | 0.0 |
N2ii—Cd1—N2—C7 | −94.1 (7) | C6—C4—C5—N1 | 180.0 |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y, z; (iii) −x, y, −z; (iv) x, −y+1, z; (v) −x, y, −z−1; (vi) −x, −y+1, −z−1. |
Experimental details
Crystal data |
Chemical formula | [CdNi(CN)4(C6H7N)2] |
Mr | 461.44 |
Crystal system, space group | Monoclinic, C2/m |
Temperature (K) | 293 |
a, b, c (Å) | 16.5198 (16), 7.3512 (7), 7.6309 (6) |
β (°) | 107.06 (1) |
V (Å3) | 885.92 (14) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.27 |
Crystal size (mm) | 0.42 × 0.36 × 0.24 |
|
Data collection |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.427, 0.580 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1793, 972, 937 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.623 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.084, 1.07 |
No. of reflections | 972 |
No. of parameters | 73 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.40, −0.60 |
Selected geometric parameters (Å, º) topCd1—N1 | 2.322 (3) | N2—C7 | 1.146 (3) |
Ni1—C7 | 1.863 (2) | | |
| | | |
N1—Cd1—N1i | 180.0 | N2iii—Cd1—N2 | 93.82 (12) |
N1—Cd1—N2ii | 91.87 (8) | N2i—Cd1—N2 | 180.0 |
N1i—Cd1—N2ii | 88.13 (8) | C7—Ni1—C7iv | 180.00 (15) |
N2ii—Cd1—N2iii | 180.00 (8) | C1—N1—Cd1 | 120.7 (3) |
N2iii—Cd1—N2i | 86.18 (12) | C5—N1—Cd1 | 121.4 (2) |
N2ii—Cd1—N2 | 86.18 (12) | | |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y, z; (iii) −x, y, −z; (iv) −x, −y+1, −z−1. |
Subscribe to Acta Crystallographica Section C: Structural Chemistry
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.
Hofmann-type complexes with the formula ML2Ni(CN)4, where M is a divalent transition metal and L is an N-donor ligand molecule, have a structure consisting of polymeric two-dimensional networks formed by [Ni(CN)4]2− anions bridged by [ML2]2+ cations. Metal coordination polymers with one- and two-dimensional structures are of current interest due to their possible relevance to material science (Yoghi et al., 1996). There is still much to be explored in the crystal engineering of Hofmann-type and analogous structures that are built up by CN linkages between square-planar or tetrahedral tetracyanometallate(II) complexes on the one hand, and octahedral metal(II) complexes ligated with complementary ligands on the other (Iwamoto et al., 1984).
The molecule of the title complex, (I) adopts a slightly distorted octahedral geometry around the Cd centre, as shown in Fig. 1. The equatorial and axial coordination sites are occupied by four N atoms of the bridging cyano groups and two N atoms of the two chelating 3-methylpyridine ligands, respectively. The structure consists of corrugated and cyanide-bridged polymeric networks made up of tetracyanonickelate ions coordinated to Cd, where the Ni ion is coordinated by four cyanide ligands in a square-planar arrangement. In this arrangement, two of the cyano groups are terminal, while the other two cyano groups, coordinated in a trans position about the Ni atom, constitute the bridges. The bonding in the networks occurs because of a departure of the Ni—C—N—Cd sequence of atoms from linearity at the C and N positions. The Ni1—C7—N2 and C7—N2—Cd bond angles are 177.2 (2) and 163.5 (2)°, respectively.
The Cd and Ni atoms of (I) lie at (0, 0, 0) and (0, 1/2, −1/2), respectively, on sites with 2/m symmetry. The non-H atoms of the 3-methylpyridine moiety lie on a mirror plane, chosen as that at y = 0. The [–Cd-{trans-NC—Ni(CN)2—CN–}] bridges run along the face diagonals of the bc plane, sharing the Cd atoms to form layers (Figs. 2 and 3). The distance between any two adjacent layers is a/2 (approximately 8.255 Å). Similar corrugated polymeric layers are also reported in some other related compounds (Erdönmez et al., 1998). The C—N and Ni—C bond distances of the square-planar Ni coordination environment are comparable with those in related Ni(CN)4 complexes (Karada~g et al., 2004; Yuge & Iwamoto, 1995; Yuge et al., 1996; Woodward et al., 2001).
The 3-methylpyridine ligands bound to the Cd atom in trans positions are located on both sides of the network and the whole 3-methylpyridine moiety, except for two H atoms of the methyl group, lies on a crystallographic mirror plane. By translation, the 3-methylpyridine aromatic rings stack in the b direction. The stacking is an offset face-to-face π–π interaction. The distance between ring centroids is 3.7789 (7) Å and the interplanar spacing is b/2.