SnI4⋅(S8)2: A Novel Adduct‐Type Infrared Second‐Order Nonlinear Optical Crystal

A simple adduct from tin tetraiodide SnI4 and octasulfur S8 , SnI4 ⋅(S8 )2 (1), is obtained employing a facile reaction. The combination of Sn4+ ions with d10 electron configuration, acentric SnI4 tetrahedra, and lone-pair effects of S8 , makes 1 a phase-matchable infrared NLO crystal with a moderate second-harmonic generation (SHG) response and a very high laser-induced damage threshold (LIDT), which is well confirmed by the DFT calculations.