Synthesis, Crystal Structures and Magnetic Properties of a Phenoxo-Bridged Dinuclear CuII Complex and a Dicyanamide Bridged Novel Molecular Rectangle Based on It

✍ Scribed by Apurba Biswas; Michael G. B. Drew; Joan Ribas; Carmen Diaz; Ashutosh Ghosh

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 581 KB
• Volume: 2011
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.201100067

✦ Synopsis

Abstract

The phenoxo‐bridged dinuclear Cu^II^ complex [Cu~2~L~2~(NCNCN)~2~] (1) and the dicyanamide‐bridged molecular rectangle [Cu~4~L~4~{μ~1,5~‐(NCNCN)~2~}]·(ClO~4~)~2~(H~2~O)~2~ (2) were synthesized using the tridentate reduced Schiff‐base ligand HL {2‐[(2‐dimethylamino‐ethylamino)methyl]phenol}. The complexes were characterized by X‐ray structural analyses and variable‐temperature magnetic susceptibility measurements. Complex 2 was formed through the joining of the phenoxo‐bridged dinuclear Cu~2~O~2~ cores of 1 via the μ~1,5~‐bridging mode of dicyanamide. The structural properties of the Cu~2~O~2~ cores in two complexes are significantly different. The geometry of the copper ions is distorted trigonal bipyramid in 1 but is nearly square‐pyramidal in 2. These differences have a marked effect on the magnetic properties of two compounds. Although both are antiferromagnetically coupled, the coupling constants (J = –185.2 and –500.9 cm^–1^ for 1 and 2, respectively) differ considerably.