Tetra­chlorido(4,4′-dimethyl-2,2′-bipyridine-κ2N,N′)platinum(IV)

Hojjat Kashani, L.; Amani, V.; Yousefi, M.; Khavasi, H.R.

doi:10.1107/S1600536808016796

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 7| July 2008| Pages m905-m906

doi:10.1107/S1600536808016796

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Tetrachlorido(4,4′-dimethyl-2,2′-bipyridine-κ²N,N′)platinum(IV)

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

^aIslamic Azad University, Shahr-e-Rey Branch, Tehran, Iran, and ^bDepartment of Chemistry, Shahid Beheshti University, Tehran 1983963113, Iran
^*Correspondence e-mail: myousefi50@yahoo.com

(Received 1 June 2008; accepted 2 June 2008; online 13 June 2008)

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, P c c n
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[F² > 2σ(F²)] = 0.038
wR(F²) = 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

Table 1
Selected geometric parameters (Å, °)

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

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)
Symmetry code: (i) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z]$ .

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 ).

Supporting information

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

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

checkCIF report

Comment top

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.

Related literature top

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 top

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%).

Computing details top

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).

Figures top

Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level [symmetry code: (a) 1/2 - x, 1/2 - y, z].

Tetrachlorido(4,4'-dimethyl-2,2'-bipyridine-κ²N,N')platinum(IV) top

Crystal data top

[PtCl₄(C₁₂H₁₂N₂)]	F(000) = 976
M_r = 521.12	D_x = 2.150 Mg m⁻³
Orthorhombic, Pccn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2ac	Cell parameters from 1510 reflections
a = 6.9497 (7) Å	θ = 2.8–29.2°
b = 13.3774 (13) Å	µ = 9.36 mm⁻¹
c = 17.3195 (16) Å	T = 298 K
V = 1610.2 (3) Å³	Prism, yellow
Z = 4	0.25 × 0.23 × 0.21 mm

Data collection top

Stoe IPDS II diffractometer	2157 independent reflections
Radiation source: fine-focus sealed tube	1779 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.049
Detector resolution: 0.15 mm pixels mm^-1	θ_max = 29.2°, θ_min = 2.8°
rotation method scans	h = −6→9
Absorption correction: numerical shape of crystal determined optically	k = −18→17
T_min = 0.172, T_max = 0.275	l = −23→18
5803 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.097	H-atom parameters constrained
S = 1.16	w = 1/[σ²(F_o²) + (0.0451P)² + 3.1448P] where P = (F_o² + 2F_c²)/3
2157 reflections	(Δ/σ)_max = 0.007
87 parameters	Δρ_max = 0.96 e Å⁻³
0 restraints	Δρ_min = −0.81 e Å⁻³

Crystal data top

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

Data collection top

Stoe IPDS II diffractometer	2157 independent reflections
Absorption correction: numerical shape of crystal determined optically	1779 reflections with I > 2σ(I)
T_min = 0.172, T_max = 0.275	R_int = 0.049
5803 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.038	0 restraints
wR(F²) = 0.097	H-atom parameters constrained
S = 1.16	Δρ_max = 0.96 e Å⁻³
2157 reflections	Δρ_min = −0.81 e Å⁻³
87 parameters

Special details top

Experimental. (X-SHAPE and X-RED; Stoe & Cie, 2005)

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 > 2sigma(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

	x	y	z	U_iso*/U_eq
Pt1	0.2500	0.2500	0.451996 (14)	0.02949 (11)
Cl1	0.0431 (2)	0.38548 (12)	0.45575 (10)	0.0500 (4)
Cl2	0.0689 (2)	0.17462 (12)	0.35700 (8)	0.0481 (3)
N1	0.4010 (6)	0.3087 (3)	0.5416 (2)	0.0316 (9)
C1	0.3349 (8)	0.2829 (4)	0.6127 (3)	0.0304 (10)
C2	0.4230 (8)	0.3185 (4)	0.6782 (3)	0.0381 (11)
H2	0.3744	0.3015	0.7265	0.046*
C3	0.5850 (8)	0.3801 (4)	0.6728 (3)	0.0399 (12)
C4	0.6800 (11)	0.4197 (6)	0.7439 (4)	0.0578 (18)
H4A	0.7228	0.3649	0.7753	0.069*
H4B	0.5898	0.4595	0.7725	0.069*
H4C	0.7884	0.4601	0.7296	0.069*
C5	0.6513 (9)	0.4028 (5)	0.5998 (4)	0.0472 (14)
H5	0.7597	0.4429	0.5942	0.057*
C6	0.5593 (9)	0.3668 (5)	0.5349 (3)	0.0424 (13)
H6	0.6065	0.3827	0.4862	0.051*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pt1	0.03027 (15)	0.03300 (16)	0.02522 (16)	−0.00577 (10)	0.000	0.000
Cl1	0.0429 (7)	0.0431 (8)	0.0638 (10)	0.0050 (6)	0.0091 (7)	0.0049 (6)
Cl2	0.0523 (8)	0.0592 (8)	0.0327 (6)	−0.0138 (7)	−0.0124 (6)	−0.0019 (6)
N1	0.031 (2)	0.035 (2)	0.0283 (19)	−0.0121 (18)	−0.0011 (16)	−0.0041 (16)
C1	0.031 (2)	0.036 (2)	0.024 (2)	−0.011 (2)	−0.0050 (19)	0.0000 (18)
C2	0.040 (3)	0.044 (3)	0.031 (2)	−0.007 (2)	−0.002 (2)	0.004 (2)
C3	0.035 (3)	0.039 (3)	0.046 (3)	−0.011 (2)	−0.007 (2)	−0.001 (2)
C4	0.054 (4)	0.070 (4)	0.049 (4)	−0.021 (4)	−0.018 (3)	−0.005 (3)
C5	0.036 (3)	0.053 (4)	0.053 (3)	−0.020 (3)	−0.006 (3)	−0.003 (3)
C6	0.040 (3)	0.052 (3)	0.035 (2)	−0.020 (3)	0.007 (2)	−0.001 (2)

Geometric parameters (Å, º) top

Pt1—N1	2.031 (4)	C2—H2	0.9300
Pt1—N1ⁱ	2.031 (4)	C3—C5	1.380 (9)
Pt1—Cl2	2.3038 (13)	C3—C4	1.494 (8)
Pt1—Cl2ⁱ	2.3038 (13)	C4—H4A	0.9600
Pt1—Cl1ⁱ	2.3146 (16)	C4—H4B	0.9600
Pt1—Cl1	2.3146 (16)	C4—H4C	0.9600
C1—N1	1.359 (6)	C5—C6	1.379 (8)
C1—C2	1.374 (7)	C5—H5	0.9300
C1—C1ⁱ	1.472 (10)	C6—N1	1.352 (7)
C2—C3	1.398 (7)	C6—H6	0.9300

N1—Pt1—N1ⁱ	80.4 (2)	C3—C2—H2	119.7
N1—Pt1—Cl2	175.58 (12)	C5—C3—C2	117.4 (5)
N1ⁱ—Pt1—Cl2	95.40 (13)	C5—C3—C4	122.0 (5)
N1—Pt1—Cl2ⁱ	95.40 (13)	C2—C3—C4	120.6 (6)
N1ⁱ—Pt1—Cl2ⁱ	175.58 (12)	C3—C4—H4A	109.5
Cl2—Pt1—Cl2ⁱ	88.85 (8)	C3—C4—H4B	109.5
N1—Pt1—Cl1ⁱ	87.72 (14)	H4A—C4—H4B	109.5
N1ⁱ—Pt1—Cl1ⁱ	89.81 (14)	C3—C4—H4C	109.5
Cl2—Pt1—Cl1ⁱ	90.96 (6)	H4A—C4—H4C	109.5
Cl2ⁱ—Pt1—Cl1ⁱ	91.34 (6)	H4B—C4—H4C	109.5
N1—Pt1—Cl1	89.81 (14)	C6—C5—C3	121.0 (5)
N1ⁱ—Pt1—Cl1	87.72 (14)	C6—C5—H5	119.5
Cl2—Pt1—Cl1	91.34 (6)	C3—C5—H5	119.5
Cl2ⁱ—Pt1—Cl1	90.96 (6)	N1—C6—C5	120.6 (5)
Cl1ⁱ—Pt1—Cl1	176.78 (8)	N1—C6—H6	119.7
N1—C1—C2	120.6 (5)	C5—C6—H6	119.7
N1—C1—C1ⁱ	115.0 (3)	C6—N1—C1	119.9 (4)
C2—C1—C1ⁱ	124.4 (3)	C6—N1—Pt1	125.3 (3)
C1—C2—C3	120.5 (5)	C1—N1—Pt1	114.8 (3)
C1—C2—H2	119.7

N1—C1—C2—C3	−1.5 (9)	C1ⁱ—C1—N1—C6	−178.3 (6)
C1ⁱ—C1—C2—C3	179.4 (7)	C2—C1—N1—Pt1	−179.3 (4)
C1—C2—C3—C5	−0.1 (9)	C1ⁱ—C1—N1—Pt1	−0.1 (8)
C1—C2—C3—C4	179.4 (6)	N1ⁱ—Pt1—N1—C6	178.1 (6)
C2—C3—C5—C6	0.7 (10)	Cl1ⁱ—Pt1—N1—C6	87.9 (5)
C4—C3—C5—C6	−178.8 (7)	Cl1—Pt1—N1—C6	−94.2 (5)
C3—C5—C6—N1	0.3 (10)	N1ⁱ—Pt1—N1—C1	0.0 (3)
C5—C6—N1—C1	−2.0 (9)	Cl2ⁱ—Pt1—N1—C1	178.7 (4)
C5—C6—N1—Pt1	−179.9 (5)	Cl1ⁱ—Pt1—N1—C1	−90.2 (4)
C2—C1—N1—C6	2.6 (9)	Cl1—Pt1—N1—C1	87.8 (4)

Symmetry code: (i) −x+1/2, −y+1/2, z.

Experimental details

Crystal data
Chemical formula	[PtCl₄(C₁₂H₁₂N₂)]
M_r	521.12
Crystal system, space group	Orthorhombic, Pccn
Temperature (K)	298
a, b, c (Å)	6.9497 (7), 13.3774 (13), 17.3195 (16)
V (Å³)	1610.2 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	9.36
Crystal size (mm)	0.25 × 0.23 × 0.21

Data collection
Diffractometer	Stoe IPDS II diffractometer
Absorption correction	Numerical shape of crystal determined optically
T_min, T_max	0.172, 0.275
No. of measured, independent and observed [I > 2σ(I)] reflections	5803, 2157, 1779
R_int	0.049
(sin θ/λ)_max (Å⁻¹)	0.686

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.097, 1.16
No. of reflections	2157
No. of parameters	87
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.96, −0.81

Computer programs: X-AREA (Stoe & Cie, 2005), X-AREA, X-RED (Stoe & Cie, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top

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

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

Symmetry code: (i) −x+1/2, −y+1/2, z.

Acknowledgements

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

References

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