supplementary materials


hg5357 scheme

Acta Cryst. (2013). E69, m623-m624    [ doi:10.1107/S160053681302905X ]

Di-[mu]-iodido-bis­(iodido­{methyl 4-[(pyridin-2-yl­methyl­idene)amino]­benzoate-[kappa]2N,N'}cadmium)

T. S. Basu Baul, S. Kundu, S. W. Ng and E. R. T. Tiekink

Abstract top

The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O2)2], is generated by the application of a centre of inversion. The Cd-I bond lengths of the central core are close and uniformly longer than the exocyclic Cd-I bond. The coordination sphere of the CdII atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-yl­methyl­idene)amino]­benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C-H...O and C-H...[pi] inter­actions, each involving the pyridine ring.

Comment top

The title compound, (I), was investigated during the course of studies into the coordination chemistry of divalent zinc triad elements with (E)-N-(pyridin-2-ylmethylidene)arylamine ligands. These complexes were investigated primarily by X-ray crystallography and proton NMR but, also included some biological studies (Basu Baul, Kundu, Höpfl et al., 2013; Basu Baul, Kundu, Linden et al., 2013; Basu Baul, Kundu, Mitra et al. 2013).

The centrosymmetric binuclear compound, Fig. 1, features a central Cd2I2 core that approximates a square as the µ2-I atoms form almost equivalent Cd—I bond lengths, each of which is longer than the terminal Cd—I bond, Table 1. The five-coordinate environment is completed by the chelating ligand which exhibits a twist as seen in the dihedral angle between the two rings of 30.78 (17)°. The coordination geometry approximates a square pyramid as judged by the value of τ = 0.13, compared with 0.0 and 1.0 for ideal square pyramidal and trigonal bipyramidal geometries, respectfully (Addison et al., 1984). In this description, the Cd atom lies 0.9208 (1) Å above the plane defined by the two µ2-I and chelating N atoms (r.m.s. deviation = 0.0690 Å) in the direction of the terminal I atom. As observed in related systems, the Cd—(pyridyl) bond length is shorter than the Cd—N(imino) bond. The ester group is twisted out of the plane of the benzene ring to which it is connected as seen in the value of the C9—C10—C13—O1 torsion angle of 161.5 (3)°.

The crystal packing is dominated by interactions involving the pyridyl residue, Table 2. Thus, pyridyl-CH···O(carbonyl) and methyl-H···π(pyridyl) interaction stabilize the three-dimensional architecture, Fig. 2.

The binuclear structure reported herein contrasts the mononuclear structures found for the zinc (Basu Baul, Kundu, Linden et al., 2013) and mercury (Basu Baul, Kundu, Mitra et al., 2013) analogues.

Related literature top

For spectroscopic, biological and structural studies of zinc triad elements with (E)-N-(pyridin-2-ylmethylidene)arylamine ligands, see: Basu Baul, Kundu, Höpfl et al. (2013); Basu Baul, Kundu, Linden et al. (2013); Basu Baul, Kundu, Mitra et al. (2013). For additional structural analysis, see: Addison et al. (1984).

Experimental top

To a solution of pyridine-2-carboxaldehyde (0.10 g, 0.93 mmol) in ethanol (3 ml) was added a solution of methyl p-aminobenzoate (0.15 g, 0.99 mmol) in ethanol (2 ml). The mixture was stirred at ambient temperature for 30 min. To this reaction mixture, a solution of CdI2 (0.36 g, 0.98 mmol) in methanol (20 ml) was added drop-wise under stirring conditions which resulted in the immediate formation of a yellow precipitate. The stirring was continued for 3 h and then the mixture was filtered. The residue was washed with methanol (3 x 5 ml) and dried in vacuo. The dried solid was dissolved by boiling in acetonitrile (40 ml) and filtered while hot. The filtrate, upon cooling to r.t., afforded yellow crystalline material. Yield 43%. M. pt:. 511–513 K. Analysis, calculated for C14H12CdI2N2O2: C, 27.71, H, 1.99, N, 4.62%; Found: C, 27.82; H, 2.05; N, 4.67%. Λm(CH3CN): 7 Ω-1cm2mol-1. IR (cm-1):1717 νasym(OCO), 1591 νasym(C(H)N). 1H-NMR (DMSO-d6; refer to Fig. 1 for atom numbering): 9.14 [d, J = 4.5 Hz, 1H, H-1], 8.73 [s, 1H, H-6], 8.16 [t, br, 1H, H-4], 8.03 [m, 3H, H-3,9,11], 7.80 [t, br, 1H, H-2], 7.57 [d, J = 8.0 Hz, 2H, H-8,12], 3.91 [s, 3H, H-14] p.p.m.. Crystals of compound suitable for X-ray crystal-structure determination were obtained from acetonitrile/chloroform by slow evaporation of the solvent at room temperature.

Refinement top

Carbon-bound H-atoms were placed in calculated positions [C—H 0.95 to 0.98 Å, Uiso(H) 1.2 to 1.5Ueq(C)] and were included in the refinement in the riding model approximation. Two reflections, i.e. (1 0 0) and (-5 0 2), were omitted from the final refinement owing to poor agreement. The maximum and minimum residual electron density peaks of 0.58 and 1.04 e Å-3, respectively, were located 0.69 Å and 0.49 Å from the I2 and I1 atoms, respectively.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2013); cell refinement: CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis PRO (Agilent, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Molecular structure of the centrosymmetric binuclear molecule of (I) showing atom-labelling scheme and displacement ellipsoids at the 50% probability level. The primed atom is related by the symmetry operation 1 - x, 1 - y, 1 - z.
[Figure 2] Fig. 2. A view of the unit-cell contents in projection down the a axis in (I). The C—H···O and C—H···π interactions are shown as orange and purple dashed lines, respectively.
Di-µ-iodido-bis(iodido{methyl 4-[(pyridin-2-ylmethylidene)amino]benzoate-κ2N,N'}cadmium) top
Crystal data top
[Cd2I4(C14H12N2O2)2]Z = 1
Mr = 1212.91F(000) = 560
Triclinic, P1Dx = 2.480 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 8.4883 (3) ÅCell parameters from 5933 reflections
b = 9.3677 (5) Åθ = 2.3–27.5°
c = 10.9029 (5) ŵ = 5.15 mm1
α = 109.516 (5)°T = 100 K
β = 95.868 (3)°Prism, yellow
γ = 90.242 (4)°0.20 × 0.15 × 0.10 mm
V = 812.18 (6) Å3
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector
3738 independent reflections
Radiation source: SuperNova (Mo) X-ray Source3374 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.031
Detector resolution: 10.4041 pixels mm-1θmax = 27.6°, θmin = 2.3°
ω scanh = 1011
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
k = 1212
Tmin = 0.698, Tmax = 1.000l = 1414
11886 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.022Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.050H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.021P)2 + 0.5485P]
where P = (Fo2 + 2Fc2)/3
3738 reflections(Δ/σ)max = 0.001
191 parametersΔρmax = 0.58 e Å3
0 restraintsΔρmin = 1.04 e Å3
Crystal data top
[Cd2I4(C14H12N2O2)2]γ = 90.242 (4)°
Mr = 1212.91V = 812.18 (6) Å3
Triclinic, P1Z = 1
a = 8.4883 (3) ÅMo Kα radiation
b = 9.3677 (5) ŵ = 5.15 mm1
c = 10.9029 (5) ÅT = 100 K
α = 109.516 (5)°0.20 × 0.15 × 0.10 mm
β = 95.868 (3)°
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector
3738 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
3374 reflections with I > 2σ(I)
Tmin = 0.698, Tmax = 1.000Rint = 0.031
11886 measured reflectionsθmax = 27.6°
Refinement top
R[F2 > 2σ(F2)] = 0.022H-atom parameters constrained
wR(F2) = 0.050Δρmax = 0.58 e Å3
S = 1.00Δρmin = 1.04 e Å3
3738 reflectionsAbsolute structure: ?
191 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
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
xyzUiso*/Ueq
I10.36407 (2)0.52109 (2)0.344025 (19)0.01447 (6)
I20.54922 (2)0.97175 (3)0.69338 (2)0.01683 (6)
Cd0.39702 (2)0.69721 (3)0.61836 (2)0.01149 (6)
N10.2891 (3)0.6752 (3)0.8000 (2)0.0118 (5)
N20.1161 (3)0.7293 (3)0.5962 (2)0.0110 (5)
O10.1491 (3)0.9351 (3)0.1141 (2)0.0162 (5)
O20.3079 (3)0.7290 (3)0.0766 (2)0.0206 (5)
C10.3737 (4)0.6588 (4)0.9039 (3)0.0153 (7)
H10.48580.65790.90630.018*
C20.3043 (4)0.6428 (4)1.0096 (3)0.0150 (7)
H20.36820.63401.08330.018*
C30.1418 (4)0.6401 (4)1.0051 (3)0.0157 (7)
H30.09150.62541.07410.019*
C40.0520 (4)0.6593 (4)0.8977 (3)0.0139 (7)
H40.06040.65820.89240.017*
C50.1304 (4)0.6800 (4)0.7980 (3)0.0123 (6)
C60.0422 (4)0.7113 (4)0.6870 (3)0.0119 (6)
H60.06970.71810.68260.014*
C70.0294 (3)0.7576 (4)0.4877 (3)0.0107 (6)
C80.1235 (4)0.6954 (4)0.4383 (3)0.0130 (6)
H80.17570.63740.48000.016*
C90.1987 (4)0.7191 (4)0.3279 (3)0.0153 (7)
H90.30210.67610.29330.018*
C100.1227 (3)0.8059 (4)0.2677 (3)0.0103 (6)
C110.0284 (3)0.8706 (4)0.3191 (3)0.0115 (6)
H110.07850.93260.27980.014*
C120.1058 (3)0.8445 (4)0.4279 (3)0.0114 (6)
H120.21010.88570.46130.014*
C130.2045 (4)0.8179 (4)0.1441 (3)0.0135 (7)
C140.2324 (4)0.9537 (4)0.0024 (3)0.0175 (7)
H14A0.23630.85750.07520.026*
H14B0.17671.03180.02480.026*
H14C0.34060.98430.01440.026*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.01401 (11)0.01747 (12)0.01205 (11)0.00245 (8)0.00116 (8)0.00518 (9)
I20.01733 (11)0.01644 (12)0.01742 (11)0.00593 (9)0.00164 (8)0.00774 (9)
Cd0.01011 (11)0.01394 (13)0.01083 (12)0.00150 (9)0.00068 (9)0.00488 (10)
N10.0126 (13)0.0116 (14)0.0107 (13)0.0020 (11)0.0000 (10)0.0034 (11)
N20.0121 (12)0.0113 (14)0.0104 (13)0.0009 (11)0.0005 (10)0.0050 (11)
O10.0210 (12)0.0152 (13)0.0131 (11)0.0027 (10)0.0055 (9)0.0078 (10)
O20.0213 (12)0.0181 (14)0.0211 (13)0.0059 (10)0.0088 (10)0.0084 (11)
C10.0165 (16)0.0139 (17)0.0142 (16)0.0020 (13)0.0026 (13)0.0043 (14)
C20.0225 (17)0.0125 (17)0.0108 (15)0.0006 (13)0.0015 (13)0.0058 (14)
C30.0226 (17)0.0133 (17)0.0139 (16)0.0012 (13)0.0035 (13)0.0076 (14)
C40.0133 (15)0.0137 (17)0.0145 (16)0.0003 (13)0.0029 (12)0.0041 (14)
C50.0137 (15)0.0115 (17)0.0116 (15)0.0002 (12)0.0019 (12)0.0037 (13)
C60.0109 (15)0.0113 (16)0.0130 (15)0.0003 (12)0.0006 (12)0.0035 (13)
C70.0117 (15)0.0106 (16)0.0086 (14)0.0021 (12)0.0001 (12)0.0020 (13)
C80.0128 (15)0.0144 (17)0.0132 (15)0.0030 (13)0.0006 (12)0.0065 (14)
C90.0107 (15)0.0173 (18)0.0169 (16)0.0026 (13)0.0014 (13)0.0052 (14)
C100.0117 (14)0.0095 (16)0.0090 (14)0.0003 (12)0.0006 (12)0.0024 (13)
C110.0123 (15)0.0095 (16)0.0127 (15)0.0021 (12)0.0040 (12)0.0030 (13)
C120.0067 (14)0.0132 (17)0.0134 (15)0.0001 (12)0.0000 (12)0.0036 (13)
C130.0138 (15)0.0134 (17)0.0126 (15)0.0019 (13)0.0006 (13)0.0040 (14)
C140.0246 (17)0.0163 (18)0.0125 (16)0.0001 (14)0.0046 (14)0.0080 (14)
Geometric parameters (Å, º) top
I1—Cd2.8765 (4)C4—C51.397 (4)
I1—Cdi2.9813 (3)C4—H40.9500
I2—Cd2.7023 (4)C5—C61.471 (4)
Cd—N12.333 (2)C6—H60.9500
Cd—N22.402 (2)C7—C121.394 (4)
Cd—I1i2.9813 (3)C7—C81.399 (4)
N1—C11.332 (4)C8—C91.388 (4)
N1—C51.346 (4)C8—H80.9500
N2—C61.280 (4)C9—C101.396 (4)
N2—C71.430 (4)C9—H90.9500
O1—C131.342 (4)C10—C111.395 (4)
O1—C141.452 (4)C10—C131.491 (4)
O2—C131.207 (4)C11—C121.390 (4)
C1—C21.396 (4)C11—H110.9500
C1—H10.9500C12—H120.9500
C2—C31.375 (5)C14—H14A0.9800
C2—H20.9500C14—H14B0.9800
C3—C41.394 (4)C14—H14C0.9800
C3—H30.9500
Cd—I1—Cdi92.716 (9)C4—C5—C6121.0 (3)
N1—Cd—N270.33 (8)N2—C6—C5120.1 (3)
N1—Cd—I2107.66 (7)N2—C6—H6119.9
N2—Cd—I2109.09 (6)C5—C6—H6119.9
N1—Cd—I1134.10 (7)C12—C7—C8120.5 (3)
N2—Cd—I187.44 (6)C12—C7—N2117.5 (3)
I2—Cd—I1117.588 (10)C8—C7—N2122.0 (3)
N1—Cd—I1i86.88 (6)C9—C8—C7119.6 (3)
N2—Cd—I1i141.81 (6)C9—C8—H8120.2
I2—Cd—I1i106.827 (10)C7—C8—H8120.2
I1—Cd—I1i87.284 (9)C8—C9—C10120.1 (3)
C1—N1—C5118.7 (3)C8—C9—H9119.9
C1—N1—Cd124.5 (2)C10—C9—H9119.9
C5—N1—Cd116.87 (19)C11—C10—C9120.1 (3)
C6—N2—C7119.8 (3)C11—C10—C13122.2 (3)
C6—N2—Cd115.35 (19)C9—C10—C13117.6 (3)
C7—N2—Cd124.74 (18)C12—C11—C10120.1 (3)
C13—O1—C14114.2 (2)C12—C11—H11120.0
N1—C1—C2122.7 (3)C10—C11—H11120.0
N1—C1—H1118.6C11—C12—C7119.6 (3)
C2—C1—H1118.6C11—C12—H12120.2
C3—C2—C1118.8 (3)C7—C12—H12120.2
C3—C2—H2120.6O2—C13—O1123.6 (3)
C1—C2—H2120.6O2—C13—C10123.2 (3)
C2—C3—C4119.0 (3)O1—C13—C10113.2 (3)
C2—C3—H3120.5O1—C14—H14A109.5
C4—C3—H3120.5O1—C14—H14B109.5
C3—C4—C5118.8 (3)H14A—C14—H14B109.5
C3—C4—H4120.6O1—C14—H14C109.5
C5—C4—H4120.6H14A—C14—H14C109.5
N1—C5—C4121.9 (3)H14B—C14—H14C109.5
N1—C5—C6117.1 (3)
Cdi—I1—Cd—N183.00 (8)Cd—N1—C5—C65.0 (4)
Cdi—I1—Cd—N2142.16 (6)C3—C4—C5—N13.0 (5)
Cdi—I1—Cd—I2107.590 (12)C3—C4—C5—C6175.7 (3)
Cdi—I1—Cd—I1i0.0C7—N2—C6—C5179.1 (3)
N2—Cd—N1—C1175.4 (3)Cd—N2—C6—C52.6 (4)
I2—Cd—N1—C170.8 (3)N1—C5—C6—N21.5 (5)
I1—Cd—N1—C1119.0 (2)C4—C5—C6—N2179.7 (3)
I1i—Cd—N1—C135.8 (3)C6—N2—C7—C12150.0 (3)
N2—Cd—N1—C54.5 (2)Cd—N2—C7—C1233.8 (4)
I2—Cd—N1—C5109.0 (2)C6—N2—C7—C832.9 (5)
I1—Cd—N1—C561.1 (2)Cd—N2—C7—C8143.3 (2)
I1i—Cd—N1—C5144.3 (2)C12—C7—C8—C90.8 (5)
N1—Cd—N2—C63.7 (2)N2—C7—C8—C9176.2 (3)
I2—Cd—N2—C6106.2 (2)C7—C8—C9—C100.7 (5)
I1—Cd—N2—C6135.4 (2)C8—C9—C10—C110.8 (5)
I1i—Cd—N2—C653.1 (3)C8—C9—C10—C13175.7 (3)
N1—Cd—N2—C7180.0 (3)C9—C10—C11—C122.2 (5)
I2—Cd—N2—C777.5 (2)C13—C10—C11—C12174.0 (3)
I1—Cd—N2—C740.9 (2)C10—C11—C12—C72.1 (5)
I1i—Cd—N2—C7123.2 (2)C8—C7—C12—C110.6 (5)
C5—N1—C1—C21.5 (5)N2—C7—C12—C11177.7 (3)
Cd—N1—C1—C2178.6 (2)C14—O1—C13—O24.4 (4)
N1—C1—C2—C31.7 (5)C14—O1—C13—C10177.0 (2)
C1—C2—C3—C42.5 (5)C11—C10—C13—O2156.5 (3)
C2—C3—C4—C50.2 (5)C9—C10—C13—O219.9 (5)
C1—N1—C5—C43.9 (5)C11—C10—C13—O122.1 (4)
Cd—N1—C5—C4176.3 (3)C9—C10—C13—O1161.5 (3)
C1—N1—C5—C6174.9 (3)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the N1,C1–C5 ring.
D—H···AD—HH···AD···AD—H···A
C1—H1···O2ii0.952.343.066 (4)133
C14—H14B···Cg1iii0.982.793.416 (4)123
Symmetry codes: (ii) x+1, y, z+1; (iii) x, y+2, z+1.
Selected bond lengths (Å) top
I1—Cd2.8765 (4)Cd—N12.333 (2)
I1—Cdi2.9813 (3)Cd—N22.402 (2)
I2—Cd2.7023 (4)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the N1,C1–C5 ring.
D—H···AD—HH···AD···AD—H···A
C1—H1···O2ii0.952.343.066 (4)133
C14—H14B···Cg1iii0.982.793.416 (4)123
Symmetry codes: (ii) x+1, y, z+1; (iii) x, y+2, z+1.
Acknowledgements top

The financial support of the University Grants Commission, New Delhi, India, to TSBB [F. No. 42–396/2013 (SR)] is gratefully acknowledged. The authors also thank the Ministry of Higher Education (Malaysia) and the University of Malaya for funding structural studies through the High-Impact Research scheme (UM.C/HIR-MOHE/SC/03).

references
References top

Addison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp, 1349–1356.

Agilent (2013). CrysAlis PRO. Agilent Technologies Inc., Santa Clara, CA, USA.

Basu Baul, T. S., Kundu, S., Höpfl, H., Tiekink, E. R. T. & Linden, A. (2013). Polyhedron, 55, 270–282.

Basu Baul, T. S., Kundu, S., Linden, A., Raviprakash, N., Manna, S. & Guedes da Silva, F. (2013). Dalton Trans. doi:10.1039/C3DT52336E.

Basu Baul, T. S., Kundu, S., Mitra, S., Höpfl, H., Tiekink, E. R. T. & Linden, A. (2013). Dalton Trans. 42, 1905–1920.

Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.

Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.