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Cobalt(II), nickel(II), and zinc(II) complexes with bidentate N,N′-bis(β-phenylcinnamaldehyde)-1,2-diiminoethane Schiff base: synthesis and structures

2002; Elsevier BV; Volume: 21; Issue: 27-28 Linguagem: Inglês

10.1016/s0277-5387(02)01277-9

1873-3719

Mehdi Amirnasr, A.H. Mahmoudkhani, Alireza Gorji, Saeed Dehghanpour, Hamid Reza Bijanzadeh,

Magnetism in coordination complexes

A series of complexes of the type M(Phca2en)X2, where Phca2en=N,N′-bis(β-phenyl-cinnamaldehyde)-1,2-diiminoethane, M(II)=Co, Ni or Zn and X=Cl, Br, I or NCS have been synthesized and characterized. The crystal and molecular structures of Co(Phca2en)Cl2 (2), Ni(Phca2en)Br2 (5) and Zn(Phca2en)Cl2 (6) were determined by X-ray crystallography from single-crystal data. Complexes 2 and 5 are isomorph and isostructure, in which the coordination polyhedron about the central metal ion is distorted tetrahedron with ClCoCl, 110.17(6)°; NCoN, 84.16(13)° and ClZnCl, 112.02(6)°; NZnN, 83.45(16)°. The complex 5 crystallizes in triclinic system with two molecules per asymmetric unit, both having nickel ion in distorted tetrahedral geometry, BrNiBr, 122.645(18)° and 125.729(18)°; NNiN, 84.63(9)° and 85.08(9)°. These structures consist of intermolecular hydrogen bonds of the type CH⋯X. The formation of the CH⋯M weak intramolecular hydrogen bonds due to the trapping of CH bonds in the vicinity of the metal atoms are reported for 2, 5 and 6. A 1H NMR study of Zn complexes gives further evidence for the presence of such interactions and their significance. The spectral properties of the above complexes are also discussed.