A new macrocyclic ligand salt, 3,5,7,7,10,12,14,14-octamethyl-l,4,8, 11-tetraazacyclotetradecane dihydrobromide dehydrate [H2LBc] Br2.2H2O and some of its metal complexes - Synthesis, characterization and antimicrobial studies

The reaction of an isomeric ligand L-B (a C-chiral isomer of 3,10-C-meso-Me-8[14]ane) with dibromoxylene resulted in an unstable N-pendent ligand salt, [(H2LBc-2H)(-CH2-C6H4-CH2-OH)(2)] Br-2. CH3OH. H2O, which on recrystalhzation yielded a stable supramolecular ligand salt [H2LBc]Br-2.2H(2)O.The structure of the new ligand salt was confirmed by X-ray crystallography. The solid state structure of ligand shows that L-Bc is protonated at the N2 and N2A nitrogen atoms and the methyl groups of L-B and L-Bc have the same axial and equatorial positions with slight changes in bond angles and bond lengths. The overall charge balance is provided by two bromide anions. In the solid state [H2LBc]Br-2. 2H(2)O shows that the 3,10 methyl groups are at axial positions and the 5,12 methyl groups at equatorial positions. L-Bc undergoes complexation with different metal salts to form the corresponding metal complexes [M(L-Bc)X-m]Y-n. xH(2)O, (M = Cu2+, Ni2+, Co3+, Zn2+, Cd2+ or Pd4+; X & Y = ClO4, NO3, Br , Cl , SCN ; m, n & x= 0, 1, 2). The metal complexes were characterized on the basis of elemental analyses; IR, UV-Vis and H-1 NMR spectroscopy, magnetic and conductance data. These complexes showed different electrolytic behavior in different solvents. The antibacterial and antifungal activities of the ligand L-Bc and its complexes toward different phytopathogemc bacteria were investigated.