LiB₉O₁₅·H₂dap·H₂O: A Cotemplated Acentric Layer-Pillared Borate Built by Mixed Oxoboron Clusters

An acentric layer-pillared borate, LiB9O15·H2dap·H2O (1, dap = 1,3-diaminopropane), cotemplated by organic and inorganic cations and build by mixed oxoboron cluster units of B6O138- and B3O75-, has first been made under solvothermal conditions, in which the B6O138- clusters link each other to form 2D layers containing 9-membered ring (MR) windows, while the B3O75- clusters join together to produce 1D chains that further perform as the pillars to connect neighboring layers, resulting in a 3D layer-pillared framework with 13- and 7-MR channels located by H2dap2+ and Li+ cations, respectively. Its second harmonic generation shows a response of ∼2.1 times that of KDP (KH2PO4).