Structural, spectral, and thermal gravimetric studies of lanthanum complexes with N,N'-tetraethyl-N''-(trichloroacetyl)phosphortriamide, 2,2'-bipyridine, and nitrate anion

Abstract

Coordination compounds of lanthanum with carbacylamidophosphate – N,N'-tetraethyl-N''-(trichloroacetyl)phosphortriamide (HL) and 2,2'-bipyridine (bipy) of composition LaLbipy2(NO3)2 and LaL3bipy were synthesized and studied by means of X-ray, thermal gravimetric analyses, IR, and NMR spectroscopy. It was established that all the ligands in the complexes are coordinated towards lanthanum in bidentate manner. Coordination number of central ion equals ten and eight for LaLbipy2(NO3)2 and LaL3bipy, respectively. Coordination polyhedron of LaIII ion has distorted geometry between bicapped square antiprism and sphenocorona in LaLbipy2(NO3)2 and between square antiprism and triangular dodecahedron in LaL3bipy. The bonds lengths La–O and La–N are commensurate in the synthesized complexes. The both structures are characterized by the presence of numerous intermolecular interactions, which have been analyzed using Hirshfeld surface tool. A feature of the complex LaLbipy2(NO3)2 is the presence of two crystallographically independent molecules in crystal. The compounds LaLbipy2(NO3)2 and LaL3bipy are thermally stable to 1750С and 1650С, respectively. A feature of the tris-complex LaL3bipy is the presence of a phase transition at a temperature of 960С.