Synthesis and spectral studies of lanthanides coordination compounds based on N-(diphenylphosphoryl)benzamide. The structure of N-(diphenylphosphoryl)benzamide

[Display omitted] •The crystal structure of N-(diphenylphosphoryl)benzamide (HL) was solved.•The novel highly luminescent lanthanide complexes were synthesized.•TG analysis and spectral studies were used to characterize synthesized compounds.•The luminescence properties of Eu(III) and Tb(III) complexes were studied.•HL efficiency as lanthanide emission sensitizer was evaluated. N-(diphenylphosphoryl)benzamide (HL), its sodium salt and new lanthanide coordination compounds of general formula LnL3⋅i-PrOH, LnL3Dipy LnL3Phen (Ln=La, Nd, Eu, Gd, Tb; Dipy=α,α′ – dipyridyl; Phen=1,10-phenanthroline) have been synthesized. The crystal structure of HL was solved. The polymeric frame of N-(diphenylphosphoryl)benzamide crystal structure was established. The infinite chains of molecules are formed by the NH⋅⋅⋅Ó type hydrogen bonds linking neighboring molecules. The synthesized coordination compounds were studied by means of thermo gravimetric analysis, IR, NMR 1H, 31P, absorption and luminescence spectroscopy at 298 and 77K. The obtained Eu(III) and Tb(III) complexes luminescence characteristics dependence on triplet states of ligands in complexes is discussed.