Zn 4 (BO 3 ) 2 (CO 2 CH 2 NH 2 ) 2 ·H 2 O: An Organic–Inorganic Hybridized KBe 2 BO 3 F 2 -like Ultraviolet Nonlinear Optical Crystal

KBe2BO3F2 (KBBF) is currently the only practical crystal capable of achieving a deep-ultraviolet (UV) laser output through direct phase matching. However, its weak interlayer interactions result in a severe layered growth habit. Enhancing the interlayer interactions in KBBF has remained a hotspot and challenge in the field of nonlinear optical (NLO) crystals. Herein, the smallest amino acid, glycine (Gly), was chosen as a small organic molecule interlayer linker to enhance the interlayer interactions, and a new KBBF-like inorganic-organic hybrid crystal, Zn4(BO3)2(CO2CH2NH2)2·H2O (ZBGly), was successfully designed and synthesized, which exhibits a short UV cutoff edge of 201 nm, a relatively strong second-harmonic generation response of 0.85 × KH2PO4, and a moderate birefringence of 0.029@546 nm. Moreover, ZBGly represents the first glycine borate featuring mixed anionic groups. This work provides new ideas for enhancing interlayer forces in KBBF structures and exploring NLO crystals.