Synthesis, characterization and magnetostructural correlation studies on three binuclear copper complexes of pyrimidine derived Schiff base ligands

Autor: Samik Gupta, Susanta Kumar Kar, Anil Kumar Barik, Shie-Ming Peng, Gene-Hsiang Lee, Somnath C. Roy, Tarak Nath Mandal, M. Salah El Fallah, Javier Tercero, Sachindranath Pal, Arijit Hazra
Rok vydání: 2008
Předmět:
Zdroj: Polyhedron. 27:2519-2528
ISSN: 0277-5387
DOI: 10.1016/j.poly.2008.05.009
Popis: Three binuclear Cu(II) complexes of two pyrimidine derived Schiff base ligands, 2- S -methyl-6-methyl-4-formyl pyrimidine- N (4)-ethyl thiosemicarbazone (HL 1 ) and salicyl hydrazone of 2-hydrazino-4,6-dimethylpyrimidine (HL 2 ), have been prepared. HL 1 produces a bis(μ-thiolato) Cu(II) complex co-crystallizing with its mononuclear analog, [Cu 2 (L 1 ) 2 (NO 3 ) 2 ][Cu(L 1 )(NO 3 )] ( 1 ). On the other hand HL 2 shows versatility by producing two different classes of binuclear Cu(II) complexes, a bis(μ-phenoxo) complex [Cu 2 (L 2 ) 2 (NO 3 ) 2 ] ( 2 ) and another a (μ-4,4′-bipyridyl) complex, [Cu 2 (L 2 ) 2 (μ-4,4′-bipyridyl)(NO 3 ) 2 ] ( 3 ) under suitable conditions. All the three complexes show distorted square pyramidal geometry around each Cu atom but to a varied extent. Magnetic behavior of complex 1 shows that it is strongly ferromagnetic in nature whereas compounds 2 and 3 are weakly antiferromagnetic in nature. A magnetostructural correlation study combined with molecular modelling on complexes 1 and 2 has thrown light on the difference on magnetic interaction between the Cu atoms in these two complexes. Various factors that may be responsible for such differences are also explored. A novel and potentially useful pH dependant conversion of 3 to 2 has also been noticed.
Databáze: OpenAIRE
Externí odkaz: