Dinuclear metal complexes of bis-macrocycles

• Published in: Coordination chemistry reviews Vol. 190; pp. 371 - 389
• Main Author: Kaden, Thomas A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-1999
• Subjects: Macrocycle; Pyrazole group; Solid dinuclear compounds; Pyrazole group; Solid dinuclear compounds; Macrocycle
• ISSN: 0010-8545; 1873-3840
• DOI: 10.1016/S0010-8545(99)00095-8

Three bis-macrocycles
7,
10,
11, consisting of two cyclononane units with a N
3, N
2S, and NS
2 donor set bridged by a pyrazole group, have been synthesized and their complexation potential studied. Several solid dinuclear compounds with Cu
2+ and Ni
2+ could be isolated and their structure elucidated. In all cases, the two metal ions are bound by the three donor atoms of the macrocycle, by the deprotonated pyrazole group and by one atom of the exogenous ligand, which bridges the two metal centres. In the case of the Cu
2+ complexes, strong anti-ferromagnetic coupling was found. In solution, ligands
7 and
10 give a series of mononuclear [Cu(LH
n
)] (
n=1, 0, −1) and dinuclear [Cu
2(LH
m
)] (
m=0, −1, −2, −3) species which have been identified and characterized by potentiometric and spectrophotometric studies. Cyclic voltammetry and ES-MS have been used to study the ternary species in solution.