A new mixed metal borate of BaPb[B5O9(OH)]·H2O with acentric structure

A new mixed matel borate, BaPb[B5O9(OH)]·H2O (1), with an acentric structure has been successfully made under hydrothermal conditions. A single-crystal X-ray structural analysis shows that 1 crystallizes in the monoclinic space group Cc (No. 9) with a = 11.3194(6) Å, b = 6.6265(3) Å, c = 12.9256(8) Å, β = 115.065(7)°, and Z = 4. Compound 1 has a layered structure with 9-membered ring (MR) windows, where the Pb2 + cations locate, while the Ba2 + cations site in the channels formed by H-bonding interactions of adjacent layers. Second-harmonic generation (SHG) measurements on the powder samples reveal that 1 exhibits SHG efficiency approximately 2.2 times that of KH2PO4 (KDP) and phase-matching. Also it has a UV cutoff edge below 200 nm.