Alkylcobalt(III) complex of a quinquedentate ligand. Preparation, characterisation, and crystal and molecular structure of 2,12-di-2-pyridyl-3,7,11-triazatrideca-2,11-diene-N2′,N2″,N3,N7,N11-(methyl)cobalt-(III) di-iodide dihydrate

Abstract

Crystals of the title compound (I) are triclinic, space group P, a= 15.310(6), b= 10.413(2), c= 8.464(2)Å, α= 97.34(2), β= 103.37(3), γ= 92.59(2)°, Z= 2. The structure was solved by the heavy-atom method and refined by full-matrix least-squares to R= 0.053 for 2 493 unique reflections measured by diffractometer. The cobalt atom of the cation has approximately octahedral co-ordination involving a methyl group and the five nitrogen atoms of the quinquedentate ligand. The methyl group is trans to a pyridine nitrogen [Co–N(1) 2.05(1)Å]: the mean of the equatorial Co–N distances is 1.96(2)Å. The water of crystallisation, secondary amino-group, and iodide ions form a hydrogen-bonded array which is discussed with reference to analytical and spectroscopic data.