Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807052555/hk2345sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807052555/hk2345Isup2.hkl |
CCDC reference: 669126
Key indicators
- Single-crystal X-ray study
- T = 120 K
- Mean (C-C) = 0.009 Å
- R factor = 0.053
- wR factor = 0.154
- Data-to-parameter ratio = 17.6
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ? PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 9
Alert level G PLAT794_ALERT_5_G Check Predicted Bond Valency for Pt1 (2) 2.99
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
For the preparation of the title compound, (I), a solution of pyrazine (60 mg, 0.74 mmol) in methanol (10 ml) was added to a solution of H2PtCl6.2H2O (200 mg, 0.37 mmol) in methanol (10 ml) at room temperature. The suitable crystals for X-ray analysis were obtained by methanol diffusion in a solution of the yellow precipitate in DMSO, after one week (yield; 150 mg, 81.6%).
H atoms were positioned geometrically, with C—H = 0.93 Å, for aromatic H atoms and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C).
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 (Bajusaz et al., 1989; Vorobevdesyatovskii et al., 1991). Due to the kinetic inertness of hexachloro- platinate(IV), cis- and trans-[PtCl4L2] complexes (L = N, O, P, S donor ligands) were mainly prepared by oxidation reactions of the corresponding platinum(II) complexes [PtCl2L2], (Hedin, 1886; Joergensen, 1900). Several PtIV complexes, with formula, [PtCl4L2], such as cis- and trans-[PtCl4– (py)2], (II), (Junicke et al., 1997), cis- and trans-[PtCl4(PzH)2], (III), (Khripun et al., 2006), trans-[PtCl4(NH3)2](1-Mu), (IV), (Witkowski et al., 1997), trans-[PtCl4(1-Prim)2], (V), (Kuduk-Jaworska et al., 1988), cis-[PtCl4(1-Etim)2], (VI), (Kuduk-Jaworska et al., 1990), trans-[PtCl4{NH=C(NMe2)OH}2], (VII), (Bokach et al., 2003), trans-[PtCl4{NH=C(Me)ON=CMe2}2], (VIII), (Kukushkin et al., 1998), cis-[PtCl4{NH=C(Et)N=CPh2}2], (IX), (Garnovskii et al., 2001), trans-[PtCl4{NH=C(Et)ON=C(OH)Ph}2].2DMSO, (X), (Luzyanin, Kukushkin et al., 2002), trans-[PtCl4{NH=C(OMe)But}2], (XI), (Gonzalez et al., 2002) and trans-[PtCl4{NH=C(OH)Et}2], (XII), (Luzyanin, Haukka et al., 2002) [where PzH is pyrazole, 1-Mu is 1-methyluracil, 1-Prim is 1-propylimidazole and 1-Etim is 1-ethylimidazoyl] have been synthesized and characterized by single-crystal X-ray diffraction methods.
There are also several PtIV complexes, with formula, [PtCl4(N—N)], such as [PtCl4(bipyi)], (XIII), (Gaballa et al., 2003), [PtCl4(Me2bim)], (XIV), (Casas et al., 2005), [PtCl4(bipy)], (XV), (Hambley, 1986), [PtCl4(dcbipy)].H2O, (XVI), (Hafizovic et al., 2006) and [PtCl4(dpk)], (XVII), (Crowder et al., 2004) [where bipyi is 2,2'-bipyrimidinyl, Me2bim is 1,1'-dimethyl-2,2'-bi-imidazolyl, bipy is 2,2'-bipyridine, dcbipy is 2,2'-bipyridine-5,5'-dicarboxylic acid and dpk is bis(2-pyridyl)ketone] 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 pyrazine and one chlorido- platinate ligands. The PtIVatom is six-coordinated in octahedral configuration by two N atoms of two pyrazine and four Cl atoms of tetrachloridoplatinate ligands. The Pt—Cl and Pt—N bond lengths and angles (Table 1) are in good agreement with the corresponding values in (II) and (VI).
In the crystal structure (Fig. 2), there are some π-π interactions between the pyrazine rings, in which they may be effective in the stabilization of the structure. The distance between the adjacent rings is 3.6485 (7) Å [symmetry codes: -1/2 - x, y, 1/2 - z; 1/2 - x, y, 1/2 - z; -1/2 + x, y, 1/2 - z; 1/2 + x, y, 1/2 - z].
For related literature, see: Hedin (1886); Joergensen (1900); Bajusaz et al. (1989); Vorobevdesyatovskii et al. (1991); 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); Gaballa et al. (2003); Casas et al. (2005); Hambley (1986); Hafizovic et al. (2006); Crowder et al. (2004).
Data collection: X-AREA (Stoe & Cie, 2005); cell refinement: X-AREA (Stoe & Cie, 2005); data reduction: X-RED (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[PtCl4(C4H4N2)2] | F(000) = 920 |
Mr = 497.06 | Dx = 2.643 Mg m−3 |
Orthorhombic, Cmca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2bc 2 | Cell parameters from 2500 reflections |
a = 7.2107 (7) Å | θ = 3.3–29.2° |
b = 14.6318 (18) Å | µ = 12.07 mm−1 |
c = 11.8392 (11) Å | T = 120 K |
V = 1249.1 (2) Å3 | Plate, yellow |
Z = 4 | 0.25 × 0.25 × 0.08 mm |
Stoe IPDSII diffractometer | 898 independent reflections |
Radiation source: fine-focus sealed tube | 883 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.099 |
Detector resolution: 0.15 mm pixels mm-1 | θmax = 29.2°, θmin = 3.3° |
rotation method scans | h = −9→9 |
Absorption correction: numerical [shape of crystal determined optically (X-RED; Stoe & Cie, 2005)] | k = −20→20 |
Tmin = 0.070, Tmax = 0.380 | l = −16→16 |
6750 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.053 | H-atom parameters constrained |
wR(F2) = 0.154 | w = 1/[σ2(Fo2) + (0.0791P)2 + 1.5933P] where P = (Fo2 + 2Fc2)/3 |
S = 1.38 | (Δ/σ)max = 0.004 |
898 reflections | Δρmax = 4.88 e Å−3 |
51 parameters | Δρmin = −3.22 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0156 (16) |
[PtCl4(C4H4N2)2] | V = 1249.1 (2) Å3 |
Mr = 497.06 | Z = 4 |
Orthorhombic, Cmca | Mo Kα radiation |
a = 7.2107 (7) Å | µ = 12.07 mm−1 |
b = 14.6318 (18) Å | T = 120 K |
c = 11.8392 (11) Å | 0.25 × 0.25 × 0.08 mm |
Stoe IPDSII diffractometer | 898 independent reflections |
Absorption correction: numerical [shape of crystal determined optically (X-RED; Stoe & Cie, 2005)] | 883 reflections with I > 2σ(I) |
Tmin = 0.070, Tmax = 0.380 | Rint = 0.099 |
6750 measured reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.154 | H-atom parameters constrained |
S = 1.38 | Δρmax = 4.88 e Å−3 |
898 reflections | Δρmin = −3.22 e Å−3 |
51 parameters |
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 > σ(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. |
x | y | z | Uiso*/Ueq | ||
Pt1 | 0.0000 | 0.0000 | 0.0000 | 0.0186 (4) | |
Cl1 | 0.22812 (15) | 0.08739 (7) | 0.08595 (9) | 0.0236 (4) | |
N1 | 0.0000 | −0.0885 (3) | 0.1339 (4) | 0.0219 (11) | |
N2 | 0.0000 | −0.2037 (4) | 0.3202 (5) | 0.0284 (12) | |
C1 | 0.0000 | −0.1797 (4) | 0.1203 (5) | 0.0242 (12) | |
H1 | 0.0000 | −0.2050 | 0.0482 | 0.029* | |
C2 | 0.0000 | −0.2356 (5) | 0.2146 (6) | 0.0266 (13) | |
H2 | 0.0000 | −0.2985 | 0.2039 | 0.032* | |
C3 | 0.0000 | −0.1117 (4) | 0.3307 (6) | 0.0254 (12) | |
H3 | 0.0000 | −0.0863 | 0.4027 | 0.030* | |
C4 | 0.0000 | −0.0545 (4) | 0.2386 (5) | 0.0237 (12) | |
H4 | 0.0000 | 0.0085 | 0.2493 | 0.028* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Pt1 | 0.0162 (4) | 0.0201 (5) | 0.0194 (5) | 0.000 | 0.000 | −0.00249 (8) |
Cl1 | 0.0211 (6) | 0.0257 (7) | 0.0239 (7) | −0.0031 (3) | −0.0027 (3) | −0.0028 (4) |
N1 | 0.016 (2) | 0.026 (2) | 0.024 (3) | 0.000 | 0.000 | −0.0021 (19) |
N2 | 0.026 (2) | 0.031 (3) | 0.028 (3) | 0.000 | 0.000 | 0.005 (2) |
C1 | 0.021 (2) | 0.024 (3) | 0.029 (3) | 0.000 | 0.000 | −0.004 (2) |
C2 | 0.025 (3) | 0.024 (3) | 0.031 (4) | 0.000 | 0.000 | 0.004 (3) |
C3 | 0.023 (3) | 0.027 (3) | 0.026 (3) | 0.000 | 0.000 | −0.002 (3) |
C4 | 0.022 (2) | 0.023 (3) | 0.026 (3) | 0.000 | 0.000 | −0.003 (2) |
Pt1—Cl1i | 2.3186 (10) | C1—H1 | 0.9300 |
Pt1—Cl1 | 2.3186 (10) | C2—N2 | 1.335 (8) |
Pt1—Cl1ii | 2.3186 (10) | C2—H2 | 0.9300 |
Pt1—Cl1iii | 2.3186 (10) | C3—N2 | 1.352 (8) |
N1—Pt1 | 2.047 (5) | C3—C4 | 1.375 (9) |
Pt1—N1i | 2.047 (5) | C3—H3 | 0.9300 |
C1—N1 | 1.344 (7) | C4—N1 | 1.336 (8) |
C1—C2 | 1.384 (9) | C4—H4 | 0.9300 |
Cl1i—Pt1—Cl1ii | 90.38 (5) | N1—C1—H1 | 120.3 |
Cl1—Pt1—Cl1ii | 89.62 (5) | C2—C1—H1 | 120.3 |
Cl1i—Pt1—Cl1iii | 89.62 (5) | N2—C2—C1 | 123.3 (6) |
Cl1—Pt1—Cl1iii | 90.38 (5) | N2—C2—H2 | 118.3 |
Cl1ii—Pt1—Cl1iii | 180 | C1—C2—H2 | 118.3 |
N1—Pt1—Cl1i | 89.48 (10) | N2—C3—C4 | 122.3 (6) |
N1i—Pt1—Cl1i | 90.52 (10) | N2—C3—H3 | 118.9 |
N1—Pt1—Cl1 | 90.52 (10) | C4—C3—H3 | 118.9 |
N1i—Pt1—Cl1 | 89.48 (10) | N1—C4—C3 | 120.6 (6) |
Cl1i—Pt1—Cl1 | 180 | N1—C4—H4 | 119.7 |
N1—Pt1—Cl1ii | 89.48 (10) | C3—C4—H4 | 119.7 |
N1i—Pt1—Cl1ii | 90.52 (10) | C4—N1—C1 | 118.8 (6) |
N1—Pt1—N1i | 180 | C4—N1—Pt1 | 118.9 (4) |
N1—Pt1—Cl1iii | 90.52 (10) | C1—N1—Pt1 | 122.4 (4) |
N1i—Pt1—Cl1iii | 89.48 (10) | C2—N2—C3 | 115.7 (6) |
N1—C1—C2 | 119.3 (6) | ||
C4—N1—Pt1—Cl1i | −134.81 (3) | N1—C1—C2—N2 | 0.0 |
C1—N1—Pt1—Cl1i | 45.19 (3) | N2—C3—C4—N1 | 0.0 |
C4—N1—Pt1—Cl1 | 45.19 (3) | C3—C4—N1—C1 | 0.0 |
C1—N1—Pt1—Cl1 | −134.81 (3) | C3—C4—N1—Pt1 | 180.0 |
C4—N1—Pt1—Cl1ii | 134.81 (3) | C2—C1—N1—C4 | 0.0 |
C1—N1—Pt1—Cl1ii | −45.19 (3) | C2—C1—N1—Pt1 | 180.0 |
C4—N1—Pt1—Cl1iii | −45.19 (3) | C1—C2—N2—C3 | 0.0 |
C1—N1—Pt1—Cl1iii | 134.81 (3) | C4—C3—N2—C2 | 0.0 |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y, −z; (iii) −x, y, z. |
Experimental details
Crystal data | |
Chemical formula | [PtCl4(C4H4N2)2] |
Mr | 497.06 |
Crystal system, space group | Orthorhombic, Cmca |
Temperature (K) | 120 |
a, b, c (Å) | 7.2107 (7), 14.6318 (18), 11.8392 (11) |
V (Å3) | 1249.1 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 12.07 |
Crystal size (mm) | 0.25 × 0.25 × 0.08 |
Data collection | |
Diffractometer | Stoe IPDSII |
Absorption correction | Numerical [shape of crystal determined optically (X-RED; Stoe & Cie, 2005)] |
Tmin, Tmax | 0.070, 0.380 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6750, 898, 883 |
Rint | 0.099 |
(sin θ/λ)max (Å−1) | 0.686 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.154, 1.38 |
No. of reflections | 898 |
No. of parameters | 51 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 4.88, −3.22 |
Computer programs: X-AREA (Stoe & Cie, 2005), X-RED (Stoe & Cie, 2005), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Pt1—Cl1 | 2.3186 (10) | N1—Pt1 | 2.047 (5) |
Cl1i—Pt1—Cl1ii | 90.38 (5) | N1—Pt1—Cl1 | 90.52 (10) |
Cl1—Pt1—Cl1ii | 89.62 (5) | Cl1i—Pt1—Cl1 | 180 |
Cl1ii—Pt1—Cl1iii | 180 | N1—Pt1—N1i | 180 |
N1—Pt1—Cl1i | 89.48 (10) |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y, −z; (iii) −x, y, z. |
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 (Bajusaz et al., 1989; Vorobevdesyatovskii et al., 1991). Due to the kinetic inertness of hexachloro- platinate(IV), cis- and trans-[PtCl4L2] complexes (L = N, O, P, S donor ligands) were mainly prepared by oxidation reactions of the corresponding platinum(II) complexes [PtCl2L2], (Hedin, 1886; Joergensen, 1900). Several PtIV complexes, with formula, [PtCl4L2], such as cis- and trans-[PtCl4– (py)2], (II), (Junicke et al., 1997), cis- and trans-[PtCl4(PzH)2], (III), (Khripun et al., 2006), trans-[PtCl4(NH3)2](1-Mu), (IV), (Witkowski et al., 1997), trans-[PtCl4(1-Prim)2], (V), (Kuduk-Jaworska et al., 1988), cis-[PtCl4(1-Etim)2], (VI), (Kuduk-Jaworska et al., 1990), trans-[PtCl4{NH=C(NMe2)OH}2], (VII), (Bokach et al., 2003), trans-[PtCl4{NH=C(Me)ON=CMe2}2], (VIII), (Kukushkin et al., 1998), cis-[PtCl4{NH=C(Et)N=CPh2}2], (IX), (Garnovskii et al., 2001), trans-[PtCl4{NH=C(Et)ON=C(OH)Ph}2].2DMSO, (X), (Luzyanin, Kukushkin et al., 2002), trans-[PtCl4{NH=C(OMe)But}2], (XI), (Gonzalez et al., 2002) and trans-[PtCl4{NH=C(OH)Et}2], (XII), (Luzyanin, Haukka et al., 2002) [where PzH is pyrazole, 1-Mu is 1-methyluracil, 1-Prim is 1-propylimidazole and 1-Etim is 1-ethylimidazoyl] have been synthesized and characterized by single-crystal X-ray diffraction methods.
There are also several PtIV complexes, with formula, [PtCl4(N—N)], such as [PtCl4(bipyi)], (XIII), (Gaballa et al., 2003), [PtCl4(Me2bim)], (XIV), (Casas et al., 2005), [PtCl4(bipy)], (XV), (Hambley, 1986), [PtCl4(dcbipy)].H2O, (XVI), (Hafizovic et al., 2006) and [PtCl4(dpk)], (XVII), (Crowder et al., 2004) [where bipyi is 2,2'-bipyrimidinyl, Me2bim is 1,1'-dimethyl-2,2'-bi-imidazolyl, bipy is 2,2'-bipyridine, dcbipy is 2,2'-bipyridine-5,5'-dicarboxylic acid and dpk is bis(2-pyridyl)ketone] 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 pyrazine and one chlorido- platinate ligands. The PtIVatom is six-coordinated in octahedral configuration by two N atoms of two pyrazine and four Cl atoms of tetrachloridoplatinate ligands. The Pt—Cl and Pt—N bond lengths and angles (Table 1) are in good agreement with the corresponding values in (II) and (VI).
In the crystal structure (Fig. 2), there are some π-π interactions between the pyrazine rings, in which they may be effective in the stabilization of the structure. The distance between the adjacent rings is 3.6485 (7) Å [symmetry codes: -1/2 - x, y, 1/2 - z; 1/2 - x, y, 1/2 - z; -1/2 + x, y, 1/2 - z; 1/2 + x, y, 1/2 - z].