The crystal and molecular structure of an isomer of chloro(RS-1,2-diaminopropane)(diethylenetriamine)cobalt(III) tetrachiorozincate(II)

Abstract

The crystal structure of B-chloro(RS-l,2-diaminopropane)(diethylenetriamine)cobalt(III) tetrachlorozincate(II) (one of the seven isolated isomers) has been determined from three-dimensional X-ray data collected by counter methods at room temperature. The crystals are monoclinic: space group C 4 sCc, with four molecules in a unit cell of dimensions a = 9.744(2), b = 13.263(3), c = 13.955(2) Å, β = 95.26(1). Observed and calculated densities are 1.79 and 1.77 g cm −3. A final value of the conventional R-factor (on F) of 0.037 was obtained from the 1331 reflections having F 2 ⩾ 3σ( F 2). The structure consists of the complex cation and discrete tetrachlorozincate(II) anions. The complex cation contains the cobalt atom surrounded by one chlorine atom and five nitrogen atoms in an approximately octahedral configuration. In this isomer, the three nitrogen atoms of the diethylenetriamine ligand are in a plane with the nitrogen atom of the 1,2-diaminopropane which is adjacent to the methyl substituted carbon atom. The other end of the 1,2-diaminopropane ligand is trans to the chlorine atom. The orientation about the secondary nitrogen group of the coordinated diethylenetriamine ligand is such that the NH proton is remote from the coordinated chlorine atom. The isolated five-membered ring has the δ configution with the methyl group in the axial orientation while the tetrachlorozincate(II) anion has a slightly distorted tetrahedral configuration.