Structural, spectral and thermal characteristics of new tetrakis-complexes (NEt4)[LnL4] with dimethyl(4-chloro-3-nitrobenzoyl)amidophosphate

Abstract

In continuation of the studies of new promising phosphors a new representative of carbacylamidophosphates (CAPhs) was synthesized and used as a ligand to obtain new lanthanides complexes (NEt4)[LnL4] (Ln = La, Y, Ce – Nd, Sm – Lu; L- = {C6H3(4-Cl-3-NO2) CONPO(OCH3)2}-). The structure of “free” ligand HL and complexes (NEt4)[YbL4] and (NEt4)[LuL4] were established by X-ray diffraction analysis. Dimethyl(4-chloro-3-nitrobenzoyl)amidophosphate has a dimeric structure. Dimers are formed by means of two hydrogen bonds of NH···OP type between two neighboring molecules. In the structure of the complexes the ligands are coordinated to the metal ion by the PO and CO groups of the chelate fragment forming six-membered not planar rings. In the crystal, the ligand and the complexes form numerous intermolecular contacts, including specific Cl···O intramolecular interaction. For the obtained compounds absorption, 1H NMR, and IR spectra were recorded and analyzed. Thermal gravimetric analysis and luminescence spectroscopy at 77 K and 298 K were used to characterize the obtained complexes.