cis-Dichloro(dimethyl sulfoxide-S)(2-methoxypyridine-N)platinum(II).

The title complex, [PtCl(2)(C(6)H(7)NO)(C(2)H(6)OS)], exhibits square-planar geometry. The plane of the pyridine ring makes a dihedral angle of 67.2 (3) degrees with the square plane of the metal center. The S-O bond is nearly aligned with the adjacent Pt-N bond, leaving the methyl groups of the dimethyl sulfoxide ligand to stagger the Pt-Cl bond.

Chloro(ethylenediamine)(6-phenylimidazo-[2,1-b]thiazole-N7)platinum(II) nitrate.

Platination of 6-phenylimidazo[2,1-b]thiazole at the imidazole N atom to give chloro(ethylenediamine)(6-phenylimidazo[2,1-b] thiazole)platinum(II) nitrate, [PtCl-(C2H8N2)(C11H8N2S)]NO3, is accompanied by a rotation of 49.3 (8) degrees of the phenyl ring and a loss of extended conjugation in the normally planar 6-phenylimidazo[2,1-b]thiazole molecule.

Crystal and molecular structure of a new Z-DNA crystal form: d[CGT(2-NH2-A)CG] and its platinated derivative.

The three-dimensional structure of d[CGTA'CG], where A' = [2-NH2-A], was determined to atomic (1.35 A) resolution by single isomorphous replacement. The d[CGTA'CG] hexamer crystallizes in space group P3221, and is not isomorphous with other DNA hexanucleotides. Despite completely different crystal packing, the essential characteristics of the Z-DNA conformation are maintained. The structure was determined by single isomorphous replacement using a triammine platinum fragment. Thus, this study also demonstrates, for the first time, the feasibility of the use of this reagent for the direct phasing of DNA crystal structures.

Platinum(II) triamine complexes: cis-[PtCl(NH3)2(C10H13N5O5)]NO3.2H2O and [PtCl(C2H8N2)(C4H6N2)]NO3.

The structures of cis-diamminechloro(guanosine-N7)-platinum(II) nitrate dihydrate, cis-[PtCl(NH3)2-(C10H13N5O5)]NO3.2H2O, (I), and chloro(ethylenediamine)(1-methylimidazole-N3)platinum(II) nitrate, [PT-(C2H8N2)(C4H6N2)Cl]NO3, [PtCl(en)(1-MeIm)]NO3, (II), were determined by single-crystal X-ray diffraction. The former complex crystallized in the orthorhombic system and the latter in the monoclinic system. In compound (I), water molecules were found to connect the metal complex with the nitrate counter ions via hydrogen bonding.

Structure of a platinum(II) complex of levamisole.

Chloro(ethylenediamine)[(-)-2,3,5,6-tetrahydro-6-phenylimidazo[2, 1-b]thiazole]platinum(II) chloride, [PtCl(C2H8N2)(C11H12N2S)]Cl, M(r) = 530.39, orthorhombic, P2(1)2(1)2(1), a = 31.676 (11), b = 8.190 (2), c = 6.6242 (6) A, V = 1718.5 (7) A3, Z = 4, Dx = 2.050 g cm-3, lambda (Mo K alpha) = 0.71069 A, mu = 86.8 cm-1, F(000) = 1016, T = 296 K, final R = 0.030 for 1646 unique observed reflections [F > 4 sigma (F)]. The Pt coordination is square planar, bonded to three N atoms (one from the levamisole and two from the ethylenediamine moiety) and to one Cl atom.