Enhanced Second-Harmonic-Generation Response in a KH2PO4-Type Calcium Nitrate Carboxylate with Unusual Three-Dimensional Inorganic and Organic Connections

An organic carboxylate ligand was employed in the synthesis of a nonhygroscopic nitrate-based nonlinear-optical (NLO) material. The hybrid-framework solid has unusual three-dimensional inorganic and organic connections with high thermal stability. Sharing similar structural features with the well-known NLO material KH2PO4 (KDP), this compound shows an enhanced second-harmonic-generation (SHG) response of about 1.6 times that of KDP. Theoretical calculations were carried out to reveal the origin of its SHG response.