Structure and magnetic properties of a syn-anti carboxylate bridged linear trinuclear copper(II) complex with ferromagnetic exchange interaction

✍ Scribed by E. Colacio; J.M. Dominguez-Vera; J.M. Moreno; J. Ruiz; R. Kivekäs; A. Romerosa

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 709 KB
• Volume: 212
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)92316-8

✦ Synopsis

The synthesis, crystal structure and magnetic properties are reported for the trinuclear compound [Cu(H,0),{Cu(HL)(H,0)(C104)}~][C10,],~2H,0, where HL is the monodeprotonated form of 6-methylamino-1,3dimethyl-5-[(2'-carboxyphenyl)azo]uracil. The compound crystallizes in the triclinic system, space group Pl, with cell constants a = 7.824(3), 6 = 12.278(3), c = 13.705(9) A, (Y= 104.34(3), /3=91.80(3), y= 103.37(5)" and Z= 1. The structure was solved and refined to R = 0.071 (R,=O.O64). The structure consists of trinuclear [Cu(H,O),{Cu(HL)(H,O)(CIO,)},lZ+ cations, non-coordinated perchlorate anions and crystal water molecules, held together by a network of hydrogen bonds. The central copper is in an elongated octahedral CuO, chromophore and the terminal copper atoms in distorted square-pyramtdal CuNO, chromophores. Adjacent copper atoms are linked by carboxylate groups in a syn-anti conformation.

From the magnetic susceptibility measurements, the complex is found to exhibit weak ferromagnetic interaction between nearest-neighbour copper(I1) ions. The magnitude and nature of the exchange coupling are discussed on the basis of the structural data.