Nonlinear Optical Responses in One-Dimensional Zinc Thiocyanates Functionalized with Natural Amino Acids

Transparent crystals of Zn(SCN)₂(l-C₆H₉N₃O₂) (1) and Zn(SCN)(l-C₅H₈NO₂)(H₂O) (2) were obtained using natural amino acids as linkers. The two compounds have one-dimensional structures that combine molecular and helical chiralities. They exhibit significant nonlinear optical responses that are phase matchable under 1064 nm laser irradiation. Notably, the second-harmonic generation efficiency of compound 2 (3.8 × KH₂PO₄) surpasses those of previously reported metal thiocyanates functionalized with natural amino acids.