Two new ternary rare earth chalcogenides, Dy3GaS6 (1) and Y3GaS6 (2), are reported here. They both crystallize in the orthorhombic space group Cmc21 (no. 36). Both are synthesized in pure phase and show phase-matchable second harmonic generation (SHG) of about 0.2 and 0.5 times, respectively for 1 and 2, as strong as that of KTiOPO4 (KTP) based on the powder SHG measurement at the wavelength of 1910 nm. They possess high powder laser induced damage thresholds (LIDTs), respectively, about 14 and 18 times that of AgGaS2 (AGS) based on the powder LIDT measurements under 1064 nm laser irradiation. They both exhibit wide transparency in the IR region (2.5–25 μm). It is believed that the title compounds are new candidates for nonlinear optical (NLO) materials in the IR region. To gain further insights into the NLO and LIDT properties of 1 and 2, the calculations of second-order NLO susceptibility and lattice energy density (LED) were also performed to explain their SHG efficiencies and high LIDTs.

Two new inorganic supramolecular compounds, (Hg11P4)(GaCl4)4 (1) and (Hg3AsS)(GaCl4) (2), have been prepared by the solid-state reactions. Their structures are characterized by mercury-containing cationic hosts and discrete (GaCl4)(-) guests, which is a derivative of a very strong Lewis acid. The three-dimensional cationic framework of 1, (Hg11P4)(4+), is marvellously extended by Hg2(2+) and Hg3(2+) groups as well as Hg(2+) ions to form two large tunnels with different sizes each embedded with two columns of (GaCl4)(-) anions. Compound 2 features a layered structure with (GaCl4)(-) tetrahedra being intercalated between two-dimensional (Hg3AsS)(+) layers and it is the first mercury pnictidechalcohalide. It is found that the weak electrostatic forces between hosts and guests play a key role in the stabilization of the whole structures of 1 and 2, which is strikingly different from almost all the reported metal pnictidehalide and chalcohalide supramolecular compounds. Optical dielectric constants calculations show that both 1 and 2 possess strong dielectric anisotropy.

Four new inorganic supramolecular complexes, [Hg4P2][ZrCl6] (1), [Hg4As2][ZrCl6] (2), [Hg4P2][HfCl6] (3), and [Hg4As2][HfCl6] (4), have been prepared by moderate‐temperature solid‐state reactions. All compounds crystallize in the space group Pbca of the orthorhombic system with Z = 8. Their structures are built up of mercury pnictide cationic hosts and distorted octahedral [MCl6]2– (M = Zr, Hf) guests. The isolated octahedral guests consist of tetravalent Zr4+ and Hf4+ cations coordinated by chlorine atoms and are embedded in the infinite channels formed by the host framework. Their optical properties were investigated in terms of their diffuse reflectance and FTIR spectra. The electronic band structures along with densities of states (DOS) calculated by DFT indicate that all of the title compounds are semiconductors with direct band gaps, and their optical absorptions mainly originate from charge transitions from Cl 3p and P 3p/As 4p states to Hg 6s, Hg 5p, and Zr 4d/Hf 5d states. Optical dielectric constant calculations show that 1–4 possess dielectric anisotropy, which is consistent with their structural studies.