Synthesis and Characterization of Nickel(II) Complexes with 18-Membered Decaaza Macrocycles 1,10-dialkyl-5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacyclooctadecane

Abstract

Six new square-planar nickel(II) complexes of 18-membered decaaza macrocyclic ligands 5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacyclooctadecane [Ni((phenyl)4 [18] ane N10)](ClO4)2 (1); 1,10-dimethyl- [Ni(Me2 (phenyl)4 [18] ane N10)](ClO4)2 (2); 1,10-diethyl- [Ni(Et2 (phenyl)4 [18] ane N10)](ClO4)2 (3); 1,10-dipropyl-[Ni(Pr2 (phenyl)4 [18] ane N10)](ClO4)2 (4); 1,10-dibutyliso- [Ni(Bu2 (phenyl)4 [18] ane N10)](ClO4)2 (5); 1,10-dibenzyl-5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacylooctadecane [Ni((Benzyl)2 (phenyl)4 [18] ane N10)](ClO4)2 (6); [Ni((phenyl)4 [18] ane N10)(NCS)2] (7); [Ni(Me2 (phenyl)4 [18] ane N10)(NCS)2] (8); [Ni(Et2 (phenyl)4 [18] ane N10)(NCS)2] (9); [Ni(Pr2 (phenyl)4 [18] ane N10)(NCS)2] (10); [Ni(Bu2 (phenyl)4 [18] ane N10)(NCS)2] (11) and [Ni(Benzyl)2 (phenyl)4 [18] ane N10)(NCS)2] (12) have been prepared from the one-pot template condensation reaction of formaldehyde, benzildihydrazone with alkyl and benzyl amine in the presence of nickel(II) ion. Elemental analyses, IR, UV-VIS spectroscopy, conductometric and magnetic measurements have been used to characterize the nickel(II) complexes of these decaaza macrocycles. The spectra of [Ni(R2 (phenyl)4 [18] ane N10)](ClO4)2 shows that the four nitrogen (α-diimine) atoms are coordinated to the nickel(II) ion. The hydrazones of the (α-diimine) function have the anti-anti configuration yielding a macrocyclic species with D2 h symmetry. The nickel(II) complexes are diamagnetic and four coordinates exhibit only weak interactions with different solvents. The physical and chemical properties of the complexes are compared with other closely related complexes.