Crystal structure of dichlorobis(1-methylcytosine)cadmium(II)
Crystals of CdCl2(1-methylcytosine)2 belong to space group Cc, with a = 10.571(7), b = 24.35(2), c = 7.097(3) Å, β = 57.33(4)°, and Z = 4. The structure was refined over 1988 independent reflections to an R factor of 0.026. The structure consists of monomeric molecules in which cadmium has a (4 + 2)-coordination. Four strong bonds, two Cd—Cl (2.497, 2.485 Å) and two Cd—N(3) (2.281, 2.296 Å), define an approximate tetrahedron around the metal. Two carbonyl oxygens take part in weak Cd—O bonding interactions (2.677, 2.780 Å). The amino groups form only very weak intramolecular hydrogen bonds with chlorine and the difference >30° between angles Cd—N(3)—C(4) and Cd—N(3)—C(2) is ascribed to Cd—O bonding. Similar effects for other metal complexes are discussed in terms of steric hindrance of the amino group and bonding of the carbonyl group.