New semiorganic nonlinear optical single crystals of BLTCM were grown by slow evaporation. Various Optical constants were calculated using the transmittance data. TGA and DSC studies shows that the crystal is thermally stable upto 204 °C. SHG efficiency of BLTCM was found to be comparable with that of KDP crystal. Laser damage threshold of BLTCM is higher than KDP.