Sulfides and Disulfides of s‐Triazine: Potential Thermal Thiyl Radical Generators

Abstract

Abstract A series of aliphatic and aromatic thioethers and dithioethers of s‐triazine were synthesised to study their thermal properties, in particular the thermally induced thiyl radical generation ability. Four symmetric s‐triazine sulfides of the type (RS) 3 C 3 N 3 , namely 2,4,6‐tris(phenylthio)‐ ( 1 ), 2,4,6‐tris( para ‐tolylthio)‐ ( 3 ), 2,4,6‐tris(ethylthio)‐ ( 5 ) and 2,4,6‐tris( tert ‐butylthio)‐1,3,5‐triazine ( 7 ), as well as four symmetric s‐triazine disulfides of the type (RSS) 3 C 3 N 3 , namely 2,4,6‐tris(phenyldithio)‐ ( 2 ), 2,4,6‐tris( para ‐tolyldithio)‐ ( 4 ), 2,4,6‐tris(ethyldithio)‐ ( 6 ) and 2,4,6‐tris( tert ‐butyldithio)‐1,3,5‐triazine ( 8 ) were synthesised. All compounds were comprehensively characterised by 1 H and 13 C NMR, infrared and Raman spectroscopy as well as elemental analyses. Single‐crystal X‐ray diffraction analyses of 1 , 2 and 5 are discussed. The thermal behaviour was studied by thermogravimetric analyses coupled with mass spectrometry (TGA‐MS) and quantum chemical calculations. Limiting oxygen index (LOI) flammability tests showed that the disulfides are the most promising radical generators, and are most likely suitable flame retardants for selected polymers.