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 Cu ~(II) M ~(II) Cu ~(II) compounds (M = Cu, Ni, Co, Fe, Mn, Zn) derived from the Schiff base ligand, H _(2) L (2 + 1 condensation product of salicylaldehyde and trans -1,2-diaminocyclohexane) are reported in this investigation. The composition of the metal complexes are [{Cu ~(II) L(ClO _(4) )} _(2) Cu ~(II) (H _(2) O)]·2H _(2) O ( 1 ), [{Cu ~(II) L(ClO _(4) )}{Ni ~(II) (H _(2) O) _(2) }{Cu ~(II) L}]ClO _(4) ·CH _(3) COCH _(3) ( 2 ), [{Cu ~(II) L(ClO _(4) )}{Co ~(II) (CH _(3) COCH _(3) )(H _(2) O)}{Cu ~(II) L(CH _(3) COCH _(3) )}]ClO _(4) ( 3 ) and isomorphic [{Cu ~(II) L(ClO _(4) )} _(2) M ~(II) (CH _(3) OH) _(2) ] ( 4 , M = Fe; 5 , M = Mn; 6 , M = Zn). Two copper( II ) ions in 1–6 occupy N _(2) O _(2) compartments of two L ~(2?) ligands, while the second metal ion occupies the O(phenoxo) _(4) site provided by the two ligands, i.e. , the two metal ions in both Cu ~(II) M ~(II) 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 = ?2 JS _(1) S _(2) type): J _(1) = ?136.50 cm ~(?1) and J = 0.00 for the Cu ~(II) Cu ~(II) Cu ~(II) compound 1 ; J _(1) = ?22.16 cm ~(?1) and J = ?1.97 cm ~(?1) for the Cu ~(II) Ni ~(II) Cu ~(II) compound 2 ; J _(1) = ?14.78 cm ~(?1) and J = ?1.86 cm ~(?1) for the Cu ~(II) Co ~(II) Cu ~(II) compound 3 ; J _(1) = ?6.35 cm ~(?1) and J = ?1.17 cm ~(?1) for the Cu ~(II) Fe ~(II) Cu ~(II) compound 4 ; J _(1) = ?6.02 cm ~(?1) and J = ?1.70 cm ~(?1) for the Cu ~(II) Mn ~(II) Cu ~(II) compound 5 ; J = ?2.25 cm ~(?1) for the Cu ~(II) Zn ~(II) Cu ~(II) compound 6 ( J is between two Cu ~(II) in the N _(2) O _(2) compartments; J _(1) is between Cu ~(II) and M ~(II) through a diphenoxo bridge).