Attempted Functionalisation of a Mononuclear Barium Complex of a 24-Membered Bibracchial Tetraimine Schiff-base Macrocycle Derived from Tris(2-Aminoethyl)amine Using Salicylaldehyde

Functionalisation of a mononuclear barium complex of a 24-membered bibracchial tetraimine Schiff-base macrocycle (L(1)) derived from the barium-templated cyclocondensation of 2,6-diacetylpyridine and tris(2-aminoethyl)amine was attempted using salicylaldehyde. The reaction leads to the isolation of the tripodal ligand tris[2-(salicylideneamino)ethyl] amine (L(2)) and the complex BaL(2)(2)(ClO4)(2). The crystal structures of the parent macrocyclic complex, [BaL(1)] [ClO4](2) [monoclinic, space group P2(1)/c (no. 14). a = 11.755(7), b = 21.733(17), c = 15.621(15) Angstrom, beta = 90.50(7)degrees, Z = 4], and BaL(2)(2)(ClO4)(2) [monoclinic, space group P2(1)/c (C-2/1(5), no. 14), a =12.299(15), b = 9.530(15). c = 25.798(32) Angstrom, beta = 108.679(9)degrees, Z = 2] have been determined.