Synthesis and crystal structure of the trans-dichloro(N,N'′-bis-[2(S)-pyrrolidylmethyl]-ethane-1,2-diamine) cobalt (III) tetrachlorocobaltate(II) complex

A trans-dichloro(N,N′-bis-[2(S)-pyrrolidylmethyl]ethane-l,2-diamine) cobalt(III) tetrachlorocobaltate(II) complex was synthesized using trans-[Co^III(pyridine)₄Cl₂]Cl, and the crystal structure was determined by X-ray analysis. This structure was also confirmed by optical spectroscopy, including circular dichroism and absorption spectra. The trans-dichloro complex was orthorhombic, space group P2₁2₁2₁ (No. 19), a = 6.404(1), b = 17.255(4), c = 23.701(2) and Z = 4. The conformations of the in-plane, containing metal and four donor atoms of N,N′-bis-[2(S)-pyrrolidylmethyl]ethane-1,2-diamine, were δ, λ and δ gauche forms. The four nitrogen donor atoms were stereoselectively directed only to the SRRS coordination. The stereoselectivity in this complex may originate from the stereospecific characteristic of the ligands.