Abstract
(R)-(+)-3-aminoquinuclidine was used in the synthesis of [(R)-C7H16N2][CuCl4] (1) and [(R)-C7H16N2][CuBr4] (2), which both contain similar [CuX4]2- anions (X = Cl or Br). The structures of the two compounds were determined using single-crystal X-ray diffraction. The use of enantiomerically pure sources of (R)-C7H14N2 forces crystallographic noncentrosymmetry. These materials crystallize in the chiral space group P212121 (No. 19), which exhibits the enantiomorphic crystal class 222 (D2). In the molecular arrangement, the [CuX4]2- anions are linked to the organic cations through NH … X and CH … X hydrogen bonds to form cation-anion-cation molecular units, which are held together by means of offset face-to-face interactions giving a three-dimensional network. Thermal stability of the crystals was ascertained by TG measurement. Compounds (1) and (2) display several phases transition with higher transition temperature at T = 100 °C. The Kurtz and Perry powder method using Nd:YAG laser shows that their second harmonic generation (SHG) efficiencies are about 0.81 and 0.82 times as large as that of KH2PO4 (KDP), respectively. Such a chiral hybrid metal halides skeleton could provide a new platform for future engineering in the areas including information storage, light modulators and optoelectronic functionalities.
•(R)-(+)-3-aminoquinuclidine was used in the synthesis of two noncentrosymmetric compounds [(R)-C7H16N2][CuCl4] and [(R)-C7H16N2][CuBr4].•Two structures were determined using single-crystal X-ray diffraction and both of them are lucky to crystallize in chiral space group P212121.•DSC measurement revealed that both compounds underwent sequential phase transitions at T(1a) = 10 °C, T(1b) = 100 °C and T(2a) = 10 °C, T(2b) = 97 °C, respectively.•Their respective SHG responses, approximately 0.81 and 0.82 times greater than that of KDP.