Dichlorido{N-[2-(diphenyl­phosphan­yl)benzyl­idene]-2-(thio­phen-2-yl)ethan­amine-κ2 P,N}platinum(II) dichloro­methane hemisolvate

Haleden Chiririwa; Alfred Muller

doi:10.1107/S1600536811056108

. 2012 Jan 7;68(Pt 2):m116–m117. doi: 10.1107/S1600536811056108

Dichlorido{N-[2-(diphenylphosphanyl)benzylidene]-2-(thiophen-2-yl)ethanamine-κ² P,N}platinum(II) dichloromethane hemisolvate

Haleden Chiririwa ^a,^*, Alfred Muller ^a,^*

PMCID: PMC3274858 PMID: 22346805

Abstract

The crystal structure of the title compound, [PtCl₂(C₂₅H₂₂NPS)]·0.5CH₂Cl₂, was determined to establish the coordination properties of the (phosphanyl)benzylidene–methanamine ligand to platinum. In the unit cell two molecules of cis-[PtCl₂(C₂₅H₂₂NPS)] are accompanied by a dichloromethane solvent molecule. The square-planar Pt²⁺ coordination sphere is slightly distorted with the bidentate ligand coordinated via the P and the amine N atoms, and the Cl atoms located cis at the two remaining coordination sites. Parts of the thiophene ring and the solvate molecule were modeled as disordered with occupancy ratios of 0.55 (2):0.45 (2) and 0.302 (10):0.198 (10), respectively. Weak C—H⋯Cl interactions stabilize the crystal packing.

Related literature

For background to related structures, see: Chiririwa et al. (2011 ▶); Chiririwa & Meijboom (2011a ▶,b ▶,c ▶); Ghilardi et al. (1992 ▶); Sanchez et al. (1998 ▶, 2001 ▶); Coleman et al. (2001 ▶). For Pt—N and Pt—P bond lengths in similar platinum(II) complexes, see: Ankersmit et al. (1996 ▶). For background to weak hydrogen-bonding interactions, see Steiner (1996 ▶).

Experimental

Crystal data

[PtCl₂(C₂₅H₂₂NPS)]·0.5CH₂Cl₂
M _r = 707.92
Monoclinic,
a = 9.9635 (7) Å
b = 19.0185 (14) Å
c = 16.0155 (9) Å
β = 122.751 (3)°
V = 2552.3 (3) Å³
Z = 4
Mo Kα radiation
μ = 5.97 mm⁻¹
T = 173 K
0.08 × 0.05 × 0.03 mm

Data collection

Bruker APEXII 4K-CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.647, T _max = 0.841
30158 measured reflections
6593 independent reflections
5165 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.028
wR(F ²) = 0.058
S = 1.01
6593 reflections
333 parameters
146 restraints
H-atom parameters constrained
Δρ_max = 0.84 e Å⁻³
Δρ_min = −0.62 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT and XPREP (Bruker, 2007 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811056108/nr2014sup1.cif

e-68-0m116-sup1.cif^{(35.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811056108/nr2014Isup2.hkl

e-68-0m116-Isup2.hkl^{(316.2KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯Cl2ⁱ	0.95	2.71	3.486 (4)	139
C12—H12⋯Cl1ⁱⁱ	0.95	2.71	3.639 (4)	168

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Financial assistance from the South African National Research Foundation (SA NRF), the Research Fund of the University of Johannesburg and SASOL is gratefully acknowledged.

supplementary crystallographic information

Comment

Platinum complexes with (phosphanyl)benzylidene-methanamine ligands have been used as catalysts or catalyst precursors for a variety of organic reactions. Our group and others have recently been interested in these types of complexes and have reported several of these types of complexes (Chiririwa et al., 2011; Chiririwa & Meijboom, 2011a, 2011b, 2011c; Ghilardi et al., 1992; Sanchez et al., (1998, 2001) and Coleman et al., 2001).

The title compound (see Fig. 1) crystallize with a dichloromethane solvate, disordered over an inversion center, for each pair of cis-[PtCl₂(C₂₅H₂₁NSP)] molecules. The square planar Pt coordination sphere is slightly distorted (Pt1 displaced -0.0275 (7)) Å from the plane formed by Pt1, P1, N1, Cl1 and Cl2 respectively; r.m.s. deviation of fitted atoms = 0.0423 Å). The distortion is featured most prominently in the N1—Pt1—P1 angle of 86.17 (10)° versus. Cl1—Pt1—Cl2 = 89.08 (4)°, indicating some ring strain induced by the chelation of the bidentate ligand. The average Pt—N and Pt—P bond lengths of 2.030 (3) and 2.2089 (9) Å, respectively are in the range expected for similar platinum(II) complexes (Ankersmit et al.(1996)). The initial refinement model of the compound showed some large displacement parameters for the thiophene moiety as well as the dichloromethane solvent. These disorders were elucidated to give an improved model (details can be found under the experimental refinement section). Two weak C—H···Cl interactions (Steiner, 1996) aid in the stabilization of the crystal structure (see Table 1, Fig. 2).

Experimental

To a dry CH₂Cl₂ (10 ml) solution of the precursor [Pt(COD)Cl₂] was added an equimolar amount of (2-(diphenylphosphanyl) benzylidene)(thiophen-2-yl)methanamine in CH₂Cl₂ (10 ml), and stirred at room temperature for 2 hrs. The solvent was reduced and the complex precipitated out on addition of hexane, filtered off, washed with Et₂O (2×5 ml) and dried under vacuum for 4 hrs affording a yellow precipitate in 72% yield. Crystals suitable for X-ray structure determination were obtained by recrystallization form a CH₂Cl₂-hexane mixture at room temperature.