Chimie douce synthesis of a new nonlinear optical material: Ba1.5VOSi2O7

K-2(NbO)(2)Si4O12 consisting of trans-connected Nb(V)O-6 octahedral chains is a novel nonlinear optical (NLO) material synthesized by Tournoux and cow orkers. Our investigation of several inorganic materials containing trans-c onnected d(0):MO6 octahedral chains has identified fresnoite (Ba2TiOSi2O7) as another structure type for second order NLO response. Here we describe t he synthesis of a new fresnoite, Ba1.5VOSi2O7, that shows efficient second harmonic generation of 1064 nm radiation, lending support to the idea that trans-connected d(0):MO6 octahedra with alternating long and short M-O dist ances is indeed a crucial structural unit for generation of efficient secon d order NLO response. (C) 2001 Editions scientifiques et medicales Elsevier SAS. All rights reserved.