Experimental and theoretical studies of a triazole ligand and complexes formed with the lanthanides

摘要

The crystal structure of 2DBTZP centre dot H_2O [DBTZP=2,6-bis(5-butyl-1,2,4-triazol-3-yl)pyridien] has been determined and shows a dimeric structure in which two ligands, with different protonation patterns, form four hydrogen bonds with an enclosed water molecule. Several crystal structures have been determined of lanthanide complexes with the corresponding 5-methyl derivative (DMTZP) which cover the lanthanide series. Four different structural types are reported: La~(III) forms [La(DMTZP)(NO_3)(H_2O)_5](NO_3)_2; Nd~(III), Sm~(III) and Tb~(III)in the first part of the lanthanide series form [M(DMTZP)(NO_3)_3(H_2O)] which is crystallographically disordered over a two-fold axis, Ho~(III) forms [Ho(DMTZP)(NO_3)_3(H_2O)], with one monodentate nitrate giving nine co-ordination, while Er~(III) and Yb~(III) form [M(DMTZP)(NO_3)_3] complexes which are also nine-co-ordinate.