Syntheses, crystal structures, magnetic properties and ESI-MS studies of a series of trinuclear CuIIMIICuII compounds (M = Cu, Ni, Co, Fe, Mn, Zn)

摘要

Six trinuclear (CuMCu)-M-vertical bar vertical bar-Cu-vertical bar vertical bar compounds (M = Cu, Ni, Co, Fe, Mn, Zn) derived from the Schiff base ligand, H2L(2 + 1) condensation product of salicylaldehyde and trans-1,2-diaminocyclohexane are reported in this investigation. The composition of the metal complexes are [{(CuL)-L-vertical bar vertical bar(CIO4)}(2)Cu-vertical bar vertical bar(H(2)u)]center dot 2H(2)O (1), [{(CuL)-L-vertical bar vertical bar(CIO4)}{Ni-vertical bar vertical bar(H2O)(2)}{(CuL)-L-vertical bar vertical bar}]CIO4 center dot CH3COCH3 (2), [{(CuL)-L-vertical bar vertical bar(Cu-vertical bar vertical bar(CIO4)}{Co-vertical bar vertical bar(CH3COCH3)}{(CuL)-L-vertical bar vertical bar((CuL)-L-vertical bar vertical bar(CH3COCH)}] CIO4 (3) and isomorphic [{(CuL)-L-vertical bar vertical bar(CIO4)}(2)M-vertical bar vertical bar(CH3OH)(2)] (4, M = Fe; 5, M = Mn; 6, M = Zn). Two copper(II) ions in 1-6 occupy N2O2 compartments of two L2- ligands, while the secondmetal ion occupies the O(phenoxo) 4 site provided by the two ligands, i.e., the twometal ions in both CuIIMII pairs are diphenoxo-bridged. Positive ESI-MS of 1-6 reveals some interesting features. Variable-temperature and variable-field magnetic studies reveal moderate or weak antiferromagnetic interactions in 1-6 with the following values of magnetic exchange integrals (H = -2JS(1)S(2) type): J(1) = -136.50 cm(-1) and J = 0.00 for the (CuCuCu vertical bar vertical bar)-Cu-vertical bar vertical bar-Cu-vertical bar vertical bar compound 1; J(1) = -22.16 cm(-1) and J = -1.97 cm(-1) for the (CuNiCu vertical bar vertical bar)-Ni-vertical bar vertical bar-Cu-vertical bar vertical bar compound 2; J(1) = -14.78 cm(-1) and J = -1.86 cm(-1) for the (CuCoCu vertical bar vertical bar)-Co-vertical bar vertical bar-Cu-vertical bar vertical bar compound 3; J(1) = -6.35 cm(-1) and J = -1.17 cm(-1) for the (CuFeCu vertical bar vertical bar)-Fe-vertical bar vertical bar-Cu-vertical bar vertical bar compound 4; J(1) = -6.02 cm(-1) and J = -1.70 cm(-1) for the (CuMnCu vertical bar vertical bar)-Mn-vertical bar vertical bar-Cu-vertical bar vertical bar compound 5; J = -2.25 cm(-1) for the (CuZnCu vertical bar vertical bar)-Zn-vertical bar vertical bar-Cu-vertical bar vertical bar compound 6 (J is between two Cu vertical bar vertical bar in the N2O2 compartments; J(1) is between Cu-vertical bar vertical bar and M-vertical bar vertical bar through a diphenoxo bridge).