Diiodidobis(triphenyl­phosphine oxide)cadmium

R Shanthakumari; R Hema; K Ramamurthy; Helen Stoeckli-Evans

doi:10.1107/S160053681005302X

. 2010 Dec 24;67(Pt 1):m114. doi: 10.1107/S160053681005302X

Diiodidobis(triphenylphosphine oxide)cadmium

R Shanthakumari ^a,^*, R Hema ^b, K Ramamurthy ^c, Helen Stoeckli-Evans ^d,^*

PMCID: PMC3050319 PMID: 21522527

Abstract

In the title compound, [CdI₂{(C₆H₅)₃PO}₂], the Cd^II atom is ligated by two I atoms and two O atoms from two triphenylphosphine oxide ligands in a disorted tetrahedral arrangement. While the O—Cd—I angles vary from 106.67 (7) to 111.23 (7)°, the O—Cd—O angle is 88.60 (10)° and the I—Cd—I angle angle is 125.47 (2)°. The crystal structure is stabilized by van der Waals forces only.

Related literature

For the structures of similar diiodo-bis(triphenylphosphine oxide)–metal complexes, see: Beagley et al. (1988 ▶); Aviles et al. (1990 ▶); Cotton et al. (2002 ▶); Nie et al. (2005 ▶). For details of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

[CdI₂(C₁₈H₁₅OP)₂]
M _r = 922.74
Orthorhombic,
a = 10.5492 (5) Å
b = 17.7053 (7) Å
c = 19.1985 (9) Å
V = 3585.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 2.45 mm⁻¹
T = 293 K
0.34 × 0.33 × 0.23 mm

Data collection

Stoe IPDS 2 diffractometer
Absorption correction: multi-scan (MULscanABS in PLATON; Spek, 2009 ▶) T _min = 0.786, T _max = 1.000
33377 measured reflections
6767 independent reflections
5935 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.050
S = 1.01
6767 reflections
389 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.42 e Å⁻³
Absolute structure: Flack (1983 ▶), 2970 Friedel pairs
Flack parameter: −0.020 (16)

Data collection: X-AREA (Stoe & Cie, 2009 ▶); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2009 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681005302X/hg2772sup1.cif

e-67-0m114-sup1.cif^{(27.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681005302X/hg2772Isup2.hkl

e-67-0m114-Isup2.hkl^{(331.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

RS thanks the UGC, India, for the award of a minor research project (File No. MRP 2976/2009). HSE thanks the staff of the XRD Appplication LAB, CSEM, Neuchâtel, for access to the X-ray diffraction eqipment.

supplementary crystallographic information

Comment

The title compound consists of discrete {Cd[(C₆H₅)₃PO]₂I₂] molecules (Fig. 1). It crystallized in the chiral orthorhombic space group P2₁2₁2₁. Each cadmium atom is ligated by two iodine atoms and two oxygen atoms, of the triphenylphosphine oxide ligands, which yield an approximate tetrahedral coordination geometry.

A search of the Cambridge Structural Database (CSD, version 5.31, last update Aug. 2010; Allen, 2002) gave 13 hits for non-solvated M[(Ph)₃PO]₂X₂ complexes (where M = Mn, Co, Ni, Cu, Zn, Hg; and X = Cl, Br, I), all of which crystallized in non-centrosymmetric space groups; Fdd2 (5×), P1(5×), Cc(1×), Pca21(1×) and Pna21(1×). The iodide complexes, which include M = Mn (Beagley et al., 1988; Aviles et al., 1990), M = Co (Cotton et al., 2002) and M = Zn (Nie et al., 2005), all crystallized in the noncentrosymmetric triclinic space group P1. The title compound is the first cadmium halide complex to be obtained and the first that crystallizes in space group P2₁2₁2₁.

The coordination polyhedron of the title compound is considerabley distorted. While the I—Cd—O angles vary from 106.67 (7) to 111.23 (7) °, angle O1—Cd1—O2 is 88.6 (1) ° and angle I1—Cd1—I2 angle is 125.47 (2) °. This differs significantly from the situation in the three iodide complexes mentioned above. There the O···M···O angles vary from 101.0 - 105.2 ° and the I—M—I angles from 112.5 - 116.3 °.

In the crystal there are no π···π stacking interactions, the molecules are simply stabilized by Van der Waals forces (Fig. 2).

Experimental

The title compound was synthesized by reacting triphenylphosphine oxide and cadmium iodide in a 1:1 (1.8 g:2.5 g) molar ratio. The calculated amount of triphenylphosphine oxide was dissolved in ethanol and the cadmium iodide was slowly added to the solution with stirring. Within a few minutes the solution became turbid. The reaction was ensured with continuous strirring. After an hour the product, a white salt, deposited at the bottom of the beaker and was then filtered and dried. This compound was recrystallized from DMSO to give colourless block-like crystals of title compound.