Novel dioxotetrazamacrocyclic 'sandwich' complexes - synthesis and structural characterization

摘要

Reaction of 1,4,7,10-tetraazacyclododecane-2,9-dione with copper and cobalt perchlorate in water at 1:1 molar ratio afforded two new crystal-engineered 1:2 'Sandwich' type complexes. Both of them are isostructural analogues. Copper complex crystallized in monoclinic space group P2_1/c with a = 9.6888(12), b = 12.2956(16), c = 10.5661(13), #beta# = 104.965(2) deg, V = 1216.0(3) A~3, and Z = 2. The Cu(II) ions are six-coordinated by four nitrogen atoms and two amide oxygen atoms. Their coordination geometry can be described as Jahn-Teller distorted octahedral, with elongated Cu-O distances. (2.310(2) A) Cobalt complex crystallized in monoclinic space group P2_1/c with a = 9.7560(12), b = 12.237(16), c = 10.7130(13), #beta# = 105.194(3) deg, V = 1234.2(4) A~3, and Z = 2. The Co(II) ions are also six-coordinated by similar atoms as found in copper complex. But the bond lengths of Co-O 2.0881(13) A are slightly shorter than respective Co-N.