Dichloridobis(pyridine-2-carboxyl­ato-κ2 N,O)platinum(IV) acetonitrile solvate

Nam-Ho Kim; In-Chul Hwang; Kwang Ha

doi:10.1107/S1600536809017966

. 2009 May 20;65(Pt 6):m667. doi: 10.1107/S1600536809017966

Dichloridobis(pyridine-2-carboxylato-κ² N,O)platinum(IV) acetonitrile solvate

Nam-Ho Kim ^a, In-Chul Hwang ^b, Kwang Ha ^a,^*

PMCID: PMC2969797 PMID: 21583028

Abstract

The asymmetric unit of the title compound, [PtCl₂(C₆H₄NO₂)₂]·CH₃CN, contains a neutral Pt^IV complex and an acetonitrile solvent molecule. In the complex, the Pt⁴⁺ atom is six-coordinated in a distorted octahedral environment by two N atoms and two O atoms from two pyridinecarboxylate (pic) ligands and two Cl atoms. The Cl atoms are cis with respect to each other. The compound displays inter- and intramolecular C—H⋯O and C—H⋯Cl hydrogen bonding.

Related literature

For the synthesis and structure of the Pt(IV)-pic complex, [PtCl₄(pic)]⁻, see: Griffith et al. (2005 ▶). For a related Pt(II)-dipicolinate complex, see: Goodgame et al. (1995 ▶).

Experimental

Crystal data

[PtCl₂(C₆H₄NO₂)₂]·C₂H₃N
M _r = 551.25
Monoclinic,
a = 6.103 (3) Å
b = 27.988 (12) Å
c = 9.823 (4) Å
β = 91.076 (7)°
V = 1677.7 (12) Å³
Z = 4
Mo Kα radiation
μ = 8.71 mm⁻¹
T = 293 K
0.20 × 0.15 × 0.15 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.203, T _max = 0.271
9732 measured reflections
3437 independent reflections
3051 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.052
S = 1.11
3437 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 1.04 e Å⁻³
Δρ_min = −0.58 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809017966/bt2950sup1.cif

e-65-0m667-sup1.cif^{(19.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809017966/bt2950Isup2.hkl

e-65-0m667-Isup2.hkl^{(168.6KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Pt1—O1	1.999 (3)
Pt1—N2	2.013 (3)
Pt1—O3	2.022 (3)
Pt1—N1	2.025 (4)
Pt1—Cl2	2.2910 (14)
Pt1—Cl1	2.3003 (13)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O2ⁱ	0.93	2.45	3.207 (7)	139
C7—H7⋯Cl1ⁱⁱ	0.93	2.75	3.583 (5)	150
C7—H7⋯Cl2	0.93	2.76	3.334 (5)	121
C10—H10⋯O4ⁱⁱⁱ	0.93	2.42	3.223 (6)	145
C13—H13A⋯O2^iv	0.96	2.43	3.256 (8)	144
C13—H13B⋯Cl1^v	0.96	2.84	3.625 (7)	140

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

This work was supported by a Korea Research Foundation grant funded by the Korean Government (MOEHRD) (KRF-2007–412-J02001).

supplementary crystallographic information

Comment

The asymmetric unit of the title compound, [PtCl₂(C₆H₄NO₂)₂].CH₃CN, contains a neutral Pt^IV complex and a CH₃CN solvent molecule (Fig. 1). In the complex, the Pt⁴⁺ ion is six-coordinated in a distorted octahedral environment by two N atoms and two O atoms from two pyridinecarboxylate (pic) anion ligands and two Cl atoms. The Cl atoms are disposed in the cis position. The main contributions to the distortion are the tight O—Pt—N chelate angles (82.32 (14)° and 82.16 (13)°), which result in non-linear trans axes (<Cl1—Pt1—N1 = 175.68 (10)°, <Cl2—Pt1—O3 = 178.67 (10)° and <O1—Pt1—N2 = 173.39 (14)°). The different trans effects of the Cl, O and N atoms are not distinct, because the Pt1—Cl, Pt1—O and Pt1—N bond lengths are almost equal (Pt1—Cl: 2.3003 (13) and 2.2910 (14) Å; Pt1—O 1.999 (3) and 2.022 (3) Å; Pt1—N 2.025 (4) and 2.013 (3) Å), respectively (Table 1). The compound displays inter- and intramolecular C—H···O and C—H···Cl hydrogen bonding (Table 2 and Fig. 2). There may also be weak intermolecular π-π interactions between adjacent pyridine rings, with a shortest centroid-centroid distance of 5.223 (4) Å.

Experimental

A suspension of K₂PtCl₆ (0.2148 g, 0.442 mmol) and pyridine-2-carboxylic acid (0.2000 g, 1.459 mmol) in H₂O (10 ml) was refluxed for 5 h. The formed precipitate was separated by filtration and washed with water (20 ml) and dried under vacuum, to give a pale green powder (0.2304 g). Colorless crystals suitable for X-ray analysis were obtained by slow evaporation from a CH₃CN solution.