STRUCTURAL, SPECTRAL, AND THERMAL GRAVIMETRIC STUDIES OF LANTHANUM COMPLEXES WITH N,N'-TETRAETHYL-N''-(TRICHLOROACETYL)PHOSPHORTRIAMIDE, 2,2'-BIPYRIDINE, AND NITRATE ANION.

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 La^III 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 175°C and 165°C, respectively. A feature of the tris-complex LaL₃bipy is the presence of a phase transition at a temperature of 96°C. [ABSTRACT FROM AUTHOR]