A new acentric metal borate Mg[B6O9(OH)2]·4H2O: Synthesis, structure and optical property

An acentric metal borate, Mg[B6O9(OH)2]·4H2O, has been successfully made under mild hydrothermal conditions. Its structure contains a novel 2-D layer constructed from the B6O11(OH)2 cluster units, which are further linked by the MgO6 polyhedra to form a 3-D framework. It has a UV cutoff edge below 200 nm and exhibits SHG efficiency approximately 1.1 times that of KDP.