Tetra­chlorido(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)platinum(IV)

Leila Hojjat Kashani; Vahid Amani; Mohammad Yousefi; Hamid Reza Khavasi

doi:10.1107/S1600536808016796

. 2008 Jun 13;64(Pt 7):m905–m906. doi: 10.1107/S1600536808016796

Tetrachlorido(4,4′-dimethyl-2,2′-bipyridine-κ² N,N′)platinum(IV)

Leila Hojjat Kashani ^a, Vahid Amani ^a, Mohammad Yousefi ^a,^*, Hamid Reza Khavasi ^b

PMCID: PMC2961848 PMID: 21202769

Abstract

The asymmetric unit of the title compound, [PtCl₄(C₁₂H₁₂N₂)], contains one half-molecule; a twofold rotation axis passes through the Pt atom and the mid-point of the C—C bond linking the two rings. The Pt^IV atom is six-coordinated in an octahedral configuration by two N atoms of the 4,4′-dimethyl-2,2′-bipyridine ligand and four terminal Cl atoms. In the crystal structure, there are weak π–π interactions between pyridine rings, with a centroid–centroid distance of 4.365 (3) Å.

Related literature

For related literature, see: Hedin (1886 ▶); Joergensen (1900 ▶); Bajusz et al. (1989 ▶); Vorobevdesyatovskii et al. (1991 ▶); Gaballa et al. (2003 ▶); Casas et al. (2005 ▶); Hambley (1986 ▶); Hafizovic et al. (2006 ▶); Delir Kheirollahi Nezhad et al. (2008 ▶); Crowder et al. (2004 ▶); Junicke et al. (1997 ▶); Khripun et al. (2006 ▶); Witkowski et al. (1997 ▶); Kuduk-Jaworska et al. (1988 ▶, 1990 ▶); Bokach et al. (2003 ▶); Kukushkin et al. (1998 ▶); Garnovskii et al. (2001 ▶); Luzyanin, Kukushkin et al. (2002 ▶); Gonzalez et al. (2002 ▶); Luzyanin, Haukka et al. (2002 ▶); Yousefi et al. (2007 ▶).

Experimental

Crystal data

[PtCl₄(C₁₂H₁₂N₂)]
M _r = 521.12
Orthorhombic,
a = 6.9497 (7) Å
b = 13.3774 (13) Å
c = 17.3195 (16) Å
V = 1610.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 9.36 mm⁻¹
T = 298 (2) K
0.25 × 0.23 × 0.21 mm

Data collection

Stoe IPDS II diffractometer
Absorption correction: numerical [shape of crystal determined optically (X-SHAPE and X-RED; Stoe & Cie, 2005 ▶)T _min = 0.172, T _max = 0.275
5803 measured reflections
2157 independent reflections
1779 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.097
S = 1.16
2157 reflections
87 parameters
H-atom parameters constrained
Δρ_max = 0.95 e Å⁻³
Δρ_min = −0.81 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2005 ▶); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2005 ▶); 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, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808016796/hk2470sup1.cif

e-64-0m905-sup1.cif^{(14.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808016796/hk2470Isup2.hkl

e-64-0m905-Isup2.hkl^{(104KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Pt1—N1	2.031 (4)
Pt1—Cl2	2.3038 (13)
Pt1—Cl1	2.3146 (16)

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N1—Pt1—N1ⁱ	80.4 (2)
N1—Pt1—Cl2	175.58 (12)
N1—Pt1—Cl2ⁱ	95.40 (13)
Cl2—Pt1—Cl2ⁱ	88.85 (8)
N1—Pt1—Cl1ⁱ	87.72 (14)
Cl2—Pt1—Cl1ⁱ	90.96 (6)
N1—Pt1—Cl1	89.81 (14)
Cl2—Pt1—Cl1	91.34 (6)
Cl1ⁱ—Pt1—Cl1	176.78 (8)

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Symmetry code: (i) Inline graphic .

Acknowledgments

We are grateful to the Islamic Azad University, Shahr-e-Rey Branch, for financial support.

supplementary crystallographic information

Comment

Amine platinum(IV) complexes have been known since the end of the last century (Hedin, 1886; Joergensen, 1900). Some of them have cancerostatic properties from which new interest aroused in these complexes (Bajusz et al., 1989; Vorobevdesyatovskii et al., 1991). Due to the kinetic inertness of hexachloro -platinate(IV), cis- and trans-[PtC1₄L₂] complexes (L=N, O, P, S donor ligand) were mainly prepared by oxidation reactions of the corresponding platinum(II) complexes [PtCl₂L₂] (Hedin, 1886; Joergensen, 1900).

Several Pt^IV complexes, with formula, [PtCl₄(N-N)], such as [PtCl₄- (bipyi)], (II), (Gaballa et al., 2003), [PtCl₄(Me₂bim)], (III), (Casas et al., 2005), [PtCl₄(bipy)], (IV), (Hambley, 1986), [PtCl₄(dcbipy)].H₂O, (V), (Hafizovic et al., 2006), [PtCl₄{pz(py)₂}], (VI), (Delir Kheirollahi Nezhad et al., 2008) and [PtCl₄(dpk)], (VII), (Crowder et al., 2004) [where bipyi is 2,2'-bi-pyrimidinyl, Me₂bim is 1,1'-dimethyl- 2,2'-bi-imidazolyl, bipy is 2,2'-bipyridine, dcbipy is 2,2'- bipyridine-5,5'-dicarboxylic acid, pz(py)₂ is 2,3-bis(2-pyridyl)pyrazine and dpk is bis(2-pyridyl)ketone] have been synthesized and characterized by single-crystal X-ray diffraction methods.

There are also several Pt^IV complexes, with formula, [PtCl₄L₂], such as cis- and trans-[PtCl₄(py)₂], (VIII), (Junicke et al., 1997), cis- and trans-[PtCl₄(PzH)₂], (IX), (Khripun et al., 2006), trans-[PtCl₄(NH₃)₂](1-Mu), (X), (Witkowski et al., 1997), trans-[PtCl₄(1-Prim)₂], (XI), (Kuduk-Jaworska et al., 1988), cis-[PtCl₄(1-Etim)₂], (XII), (Kuduk-Jaworska et al., 1990), trans-[PtCl₄{NH=C(NMe₂)OH}₂], (XIII), (Bokach et al., 2003), trans-[PtCl₄{NH=C(Me)ON=CMe₂}₂], (XIV), (Kukushkin et al., 1998), cis-[PtCl₄{NH=C(Et)N=CPh₂}₂], (XV), (Garnovskii et al., 2001), trans- [PtCl₄{NH=C(Et)ON=C(OH)Ph}₂].2DMSO, (XVI), (Luzyanin, Kukushkin et al., 2002), trans-[PtCl₄{NH=C(OMe)Bu^t}₂], (XVII), (Gonzalez et al., 2002), trans-[PtCl₄{NH=C(OH)Et}₂], (XVIII), (Luzyanin, Haukka et al., 2002) and trans- [PtCl₄(pz)₂], (XIX), (Yousefi et al., 2007) [where PzH is pyrazole, 1-Mu is 1-methyluracil, 1-Prim is 1-propylimidazole, 1-Etim is 1-ethylimidazoyl and Pz is pyrazine] have been synthesized and characterized by single-crystal X-ray diffraction methods. We report herein the synthesis and crystal structure of the title compound, (I).

The asymmetric unit of (I) (Fig. 1) contains one-half molecule. The Pt^IV atom is six-coordinated in octahedral configuration (Table 1) by two N atoms of 4,4'-dimethyl-2,2'-bipyridine ligand and four terminal Cl atoms. The Pt-Cl and Pt-N bond lengths and angles (Table 1) are in good agreement with the corresponding values in (II), (III), (V) and (VI).

In the crystal structure, weak π—π interactions between pyridine rings [symmetry code: 3/2 - x, 1/2 - y, z] may be effective in the stabilization of the structure, with a centroid-centroid distance of 4.365 (3) Å.

Experimental

For the preparation of the title compound, a solution of 4,4'-dimethyl-2,2' -bipyridine (0.11 g, 0.58 mmol) in methanol (10 ml) was added to a solution of H₂PtCl₆.6H₂O, (0.30 g, 0.58 mmol) in methanol (10 ml) at room temperature. Crystals suitable for X-ray analysis were obtained by methanol diffusion in a solution of yellow precipitate in DMSO after one week (yield; 0.25 g, 82.8%).