Structure of the stable isomer of the bis(ethane-1,2-diamine)(N-methylethane-1,2-diamine)cobalt(III) cation, [Co(meen)(en)2]3+

Abstract

Bis(ethane-1,2-diamine-N,N')(N-methyl-ethane-1,2-diamine-N,N')cobalt(III) triperchlorate monohydrate, [Co(C₃H10N₂)(C₂H₈N₂)₂](ClO₄)₃.H₂O, M(r) = 569.6, monoclinic, P2₁/n, a = 10.280 (1), b = 13.905 (2), c = 14.533 (2) A, β = 90.30 (1)-degrees, V = 2077 (2) A³, Z = 4, D(x) = 1.821 g cm⁻³, λ(Mo Kα) = 0.7107 A, μ = 12.84 cm⁻¹, F(000) = 1176, T = 293 (1) K, R = 0.051 for 2138 observed reflections. The Co atom in the cation is octahedrally coordinated by six N atoms from three chelating diamine ligands; Co-N 1.967 (5)-1.999 (5) A, with Co-N(CH₃) the longest. The structure is a racemate and the conformational structure is Λ-R-δ*λλ (for one enantiomer). Comparisons are made with the structure calculated by molecular mechanics using an MM2 force field. The crystal lattice is held together via hydrogen bonds involving the cation, perchlorate anions and the water molecule of crystallization.