Synthesis, Structure, and Optical Properties of a 0D Hybrid Organic–Inorganic Metal Halide (C5N2H14Cl)GeCl3

Due to the flexible structural tunability and excellent photoelectric performance, hybrid organic–inorganic metal halides (OIMHs) have attracted intensive attention and become a hot topic in the field of materials. It is important and necessary to explore new OIMHs and study their structure–property relationship. In this work, a new lead-free OIMH, (C5N2H14Cl)GeCl3, is synthesized by the combination of hydrothermal and solution methods. This compound features a zero-dimensional structure composed of inorganic [GeCl3]− trigonal pyramids surrounded by isolated Cl– anions and organic (C5N2H14)2+ cations. Preliminary characterization and first-principles calculations are performed to study its basic optical properties. Interestingly, (C5N2H14Cl)GeCl3 shows weak blue emission under ultraviolet excitation, and the intrinsic mechanism is discussed.