NIR luminescence of one-dimensional tartaric acid derivatives neodymium coordination polymers

Abstract

A series of four neodymium coordination polymers (CPs), namely, {[Nd2L3(CH3OH)3(H2O)4]}n(1), {[Nd2L3(CH3OH)4(H2O)3]·4CH3OH·H2O}n(2), {[Nd2L3(CH3OH)4(H2O)3]·4CH3OH·H2O}n(3) and [NdL'3(CH3OH)3]n(4) have been isolated by facile reactions of ligands (H2L=L-di-2-thenoyltartaric acid and H2L'=L-di-p-toluoyl-tartaric acid) with NdCl3·6H2O at ambient temperature depending on the reaction conditions. X-ray crystallographic analysis reveals that all complexes 1–4 feature one-dimensional (1D) network structure in which the Nd3+ ions are bridged by carboxylate groups of ligands by five types of coordinated modes. Complexes 1–3 feature one-dimensional (1D) ladder-like chain structure and complex 4 features one-dimensional (1D) linear structure owing tothe ligands coordination modes. NIR luminescence analysis reveal that all complexes 1–4 exhibit three characteristic bands around 890, 1054 and 1326nm of Nd3+ ion in which complex 3 shows the longest lifetime and highest quantum yield. The energy transfer processes among ligands, the Nd3+ ion and the auxiliary ligand in complexes 1–4 has been investigated.