Synthesis, X-ray crystal structure, and solution properties of nickel(II) complexes of new 16-membered mixed-donor-macrocyclic Schiff base ligand incorporating a pendant alcohol function

The synthesis of N2O3 macrocyclic ligand 8,9,18,19-tetrahydro-7H,17H-dibenzo[fo][1,5,9,13] dioxadiazacyclohexadecin-18-ol (L = 2) and preparation of complexes NiLX2 (X = Cl, Br, 1, ClO4) and NiLXY (X = Cl, Br, I and Y = ClO4) are reported. NiLX2 complexes were prepared by facile template reactions of appropriate dialdehyde 2-[3-(2-formylphenoxy)-2-hydroxypropoxy]bezaldehyde (1) and 1,3-diaminopropane in the presence of Ni(II) salts. Reactions of NiL(ClO4)(2) (2d) with lithium halides resulted in NiLXY complexes. From spectroscopic measurements and conductivity studies of the complexes it is followed that the six-coordinate species NiLX+ are formed in solution except 2d. In all complexes the ligand behaves as a pentadentate ligand. Complexes 2b . CH3CN and 2b . 1.75CH(3)CN (2b = NiLBr2) contain nickel in a distorted octahedral environment of N2O3Br donors. (C) 2003 Elsevier Science Ltd. All rights reserved.