Synthesis, structure and characterization of zinc(II), copper(II), zinc(II) barium(II) and copper(II) barium(II) complexes of macrocyclic heteronucleating ligands based on isothiosemicarbazide

The linear polyether dialdehydes (2-hydroxybenzaldehyde-3-yl)-O-(CH2CH2O)(n)-(3-yl-2-hydroxybenzaldehyde), where n=3 (1), 4 (2), react with S-methylisothiosemicarbazide hydroiodide (or hydrochloride) in the presence of Ba(CF,SO,), and zinc(II) acetate and/or copper(II) acetate in methanol/THF to give [(ZnBaLI)-I-1(CF3SO3) (CH3OH)](2). 0.5H(2)O (5), [CuBaL1(CF3SO3)(2)](2) (8) and [CuBaL2(CF3SO3)(2)](2) (10). Treatment of 5 with AgCF3SO3 in methanol and subsequent recrystallization from ethanol results in loss of I- to give [ZnBaL1 (CF3SO3)(2)(H2O)](2) (6). Removal of the Ba2+ from 6, 8 and 10 by using an aqueous solution of guanidinium sulfate affords ZnL1. H2O (7), CuL1. 2H(2)O (9) and CuL2. 2H(2)O (11). The molecular structure of 5 has been determined by X-ray crystallography. Crystal data for 5: monoclinic, P2(1)/c,a= 9.331(1), b = 15.293(2), c =25.940(2) Angstrom, beta = 97.94(1)degrees,Z= 2. Electronic and NMR spectra, the magnetic behavior, ESR and mass spectra, and the electrochemistry of the new compounds are discussed. (C) 1998 Elsevier Science S.A. All rights reserved.