Novel second-harmonic-generation-active lead(ii) phosphinate based on 2-carboxyethyl(phenyl)phosphinate ligand

Abstract

The hydrothermal reaction of PbCl₂ with the achiral 2-carboxyethyl(phenyl)phosphinate ligand (H₂L) afforded a novel lead(II) phosphinate that contains two enantiomers as a racemic mixture, namely, [Pb(HL)₂] (Λ- and Δ-1). Each enantiomer features a two-fold symmetrical chiral chain, in which the adjacent Pb²⁺ ions are doubly bridged by pairs of HL⁻ ligands. The uni-oriented stacking of such 1D chains by edge-to-face π⋯π interactions results in its crystallization in the chiral C2 space group. Complex 1 shows a second harmonic generation response that is ∼2 times that of KDP (KH₂PO₄).