Bidenticity-Enhanced Second Harmonic Generation from Pb Chelation in Pb_3Mg_3TeP_2O_(14)

摘要

A new ultraviolet nonlinear optical (NLO) material, Pb_3Mg_3TeP_2O_(14) (PMTP), has been synthesized and characterized. The chiral material exhibits a large second harmonic generation (SHG) response of 13.5 X KDP (600 × α-SiO_2), and the shortest absorption edge (250 nm) of reported materials with a strong SHG response (＞10 × KDP). PMTP has a three-dimensional crystal structure of corner-shared MgO_4, PO_4 and TeO_6 polyhedra, which form a [TeMg_3P_2O_(14)]_∞ framework. Electronic structure calculations revealed that the stereo-active lone pair on the Pb~(2+) cation is critical to producing the substantial NLO response and that the NLO activity is further enhanced by the presence of triply bidentate Te~(6+) cations found in Te-O-O-Pb lines.