Syntheses, crystal structures and quantum chemistry study of the rare earth complexes with the benzimidazole derivative ligand

Three new lanthanide complexes with the butyl-substituted N, N, N', N'-tetrakis (2-benzimidazolylmethyl)-1,2-ethanediamine (BuEDTB), [M( BuEDTB) (NO3)(2)] . NO3 . 4H(2)O [M = La (1), Eu (2) Tb (3)] were synthesized. The crystal structure of 1 was determined by X-ray diffraction analysis. It belongs to trigonal system, space group, P3(2)21 with a = 1.41353 (9) nm, c= 2.6264(4) nm; Z = 3, V = 4.5447 (9) nm(3), D-c 1.189 g/cm(3), mu = 0.758 mm(-1), F (000) = 1686, R = 0.0562, wR = 0.1488. The lanthanum ion is coordinated to six nitrogen atoms from one molecule of BuEDTB and four oxygen atoms from two nitrate ions. But the third nitrate ion is free. The electronic structure of BuEDTB was studied using the ab inito HF method.