Multiple Functions of l-Thioproline in the Synthesis of Chiral Metal Bromides Showing Second-Harmonic-Generation Responses.

Three new homochiral metal bromides, namely, (l-Htp) 2 Cu 2 Br 4 ( 1 ), (l-Htp)(l-tp)CdBr 3 ( 2 ), and (l-tp) 2 ZnBr 2 ( 3 ), were prepared using l-thioproline as the chiral template. These compounds feature dimeric, chainlike, and monomeric structures. Their second-harmonic-generation (SHG) efficiencies are 0.1, 0.3, and 2.0 times that of KH 2 PO 4 , respectively. Density functional theory calculations were performed to reveal the origin of the SHG response of compound 3 .