Synthesis and hypodentate Cu(II) complexes of new tripodal tetraamine ligands incorporating a long pendant arm

• Published in: Polyhedron Vol. 23; no. 1; pp. 97 - 102
• Main Authors: Lundin, Natasha J, Hamilton, Ian G, Blackman, Allan G
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2004
• Subjects: Crystal structure; Cu(II) complexes; Five-coordinate; Hypodentate; Tripodal amine ligand; Cu(II) complexes; Tripodal amine ligand; Hypodentate; Five-coordinate; Crystal structure
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2003.09.030

The tetrahydrochloride salts of the new tripodal ligands apba (
N-(5-aminopentyl)-
N,N-bis(2-aminoethyl)amine) and ahba (
N-(6-aminohexyl)-
N,N-bis(2-aminoethyl)amine) react with CuCO
3
·
Cu(OH)
2 to give complexes in which the ligands are coordinated in a hypodentate fashion, with the longest pendant arm of the ligands remaining protonated and unbound.
The synthesis and characterisation of the new aliphatic tripodal amine ligands apba (
N-(5-aminopentyl)-
N,N-bis(2-aminoethyl)amine) and ahba (
N-(6-aminohexyl)-
N,N-bis(2-aminoethyl)amine) are reported. The tetrahydrochloride salts of these ligands, as well as that of the previously reported ligand abba (
N-(4-aminobutyl)-
N,N-bis(2-aminoethyl)amine), react with CuCO
3
·
Cu(OH)
2 to give complexes in which the tripodal ligand coordinates to the Cu(II) ion in a hypodentate fashion, with the longest arm of the tripodal ligand remaining protonated and unbound in all cases. The crystal structure of [Cu(abbaH)Cl
2]Cl
·
2H
2O
·
CH
3OH reveals a five-coordinate Cu(II) ion in a slightly distorted square pyramidal geometry.