Light harvesting indolyl-substituted phosphoramide ligand for the enhancement of Mn(ii) luminescence

Abstract

The reaction of N,N,N',N'‐tetramethyl‐P‐indol‐1‐ylphosphonic diamide (L) with Mn(II) halides under mild conditions allowed the isolation of tetrahedral neutral complexes having general formula [MnX2L2] (X = Cl, Br, I). The structures of the new coordination compounds were ascertained by single‐crystal X‐ray diffraction. The three species exhibited noticeable luminescence in the green region upon excitation with UV light, with emissions related to the Mn(II) 4T1(4G)→6A1(6S) transition, without appreciable luminescence from the coordinated ligands. Luminescence was caused by both metal and ligand excitations. The good light harvesting features of the indol‐1‐yl fragment allowed the luminescence enhancement with respect to comparable phenyl‐substituted derivatives.