Crystal Engineering of Three Novel 1-D Chalcogenidostannates Using Lanthanide Complexes as Structure-Directing Agents: Synthesis, Structure, and Photoelectric Performance Evaluation

Crystalline lanthanide compounds have broad application prospects in the field of photoelectric properties. In this paper, we report the surfactant-thermal method to prepare three novel lanthanide chalcogenidostannates, [Eu(trien)(tren)(Cl)]2Eu2Sn2S9·H2O (1) (trien = triethylenetetramine, tren = tris(2-aminoethyl) amine), [Nd(trien)2Cl]HgSnSe4 (2), and [Sm(trien)(tren)Cl]Hg2SnSe5 (3), by applying poly(ethylene glycol)-400 (PEG-400) as the reaction medium. 1 crystallizes in the orthorhombic crystal system Pmmn, whereas 2 crystallizes in Pna21 in the noncentrosymmetric orthorhombic space group, and powder second-harmonic-generation (SHG) measurement reveals that the SHG response exhibited by compound 2 is roughly half as intense as that observed in AgGaS2, and 3 crystallizes in the monoclinic crystal system P21/m. 1 is the first example of Eu3+ ions being introduced into a purely inorganic skeleton; in 2 and 3, the transition metal (TM) ion Hg2+ is incorporated into the [SnxQy]n− (Q = S/Se) system to form complex TM-chalcogenidostannate anions. 1, 2, and 3 exhibit band gaps of 2.13, 2.01, and 1.98 eV, respectively. Notably, all three compounds display impressive photocurrent densities, with compound 3 standing out with a density of 54 μA/cm2. Compounds 1–3 showed remarkable photodegradation of methyl blue (MB), especially compound 3, which had a degradation efficiency of 61.1%. To gain a deeper understanding of the correlation between their optical properties and their electronic structures, theoretical calculations were conducted.