Chiral metal complexes. 51. Structure of the DNA probe Lambda-alpha-[N,N '-dimethyl-1,6-di(2-pyridyl)-2,5-diazahexane][S-phenylalaninato(1-)]cobalt(III) perchlorate

The ternary complex Lambda-alpha-[N,N'-dimethyl-1,6-di(2-pyridyl)-2,5-diaza hexane][S-phenylalaninato(1-)cobalt](III) perchlorate has been isolated fro m aqueous solution as the least soluble diastereoisomer. Crystals are ortho rhombic, space group P2(1)2(1)2(1) with a=10.462(2), b= 12.895(3), c = 22.5 60(3) Angstrom, V = 3043.4 Angstrom(3), Z = 4, D-c = 1.480 and D-m = 1.48. The structure was refined by full-matrix least-squares to a final R value o f 0.054 for 1797 reflections with I > 2 sigma(I). In the structure, the phe nyl ring of the phenylalanine ligand is bonded face-to-face, albeit slightl y offset, to one of the pyridine rings of the tetradentate. H-1 NMR measure ments show that this indicated weak interaction between the rings persists in solution.