One-Dimensional Double Chains in Sodium-Based Quaternary Chalcogenides Displaying Intriguing Red Emission and Large Optical Anisotropy

A new family of Na3AgSnQ4 (Q = S or Se) and Na3MIIInS4 (MII = Cd or Hg) was successfully synthesized in vacuum-sealed silica tubes for the first time. They exhibit similar isolated one-dimensional (1D) double chains {[AgSnQ4]n vs [(MII/In)S4]n} in their structures. After the detailed survey on the Inorganic Crystal Structure Database, title compounds can be described as the first discovered examples exhibiting novel 1D double-chain configurations in the known 171 (MIB and MIVA) or 48 (MIIB and MIIIA) element-based quaternary A–MIB/MIIB–MIVA/MIIIA–Q chalcogenides. In addition, their dimensionalities on the mode of connection between two anionic groups are closely related to the empirical A/(IB+IVA) and A/(IIB+IIIA) in the unit cell or the (IB+IVA)/Q and (IIB+IIIA)/Q ratios, which may produce a good way to predict and design new chalcogenides with low-dimensional structures. Photoluminescence measurement shows that Na3CdGaS4 and Na3CdInS4 display strong red emission (648 and 647 nm) at room temperature that...