Thermal deprotonation and condensation of melamine in the presence of indium()chloride

The thermal condensation of melamine into molecules melam, melem, and the one-dimensional polymer melon has already been reported. An interesting question arises about the impact of other compounds being present in this process of thermal conversion. The solid-state reaction of C 3 N 6 H 6 with InCl 3 leads to a novel compound featuring deprotonated melam units in a supramolecular assembly, based on the [C 12 N 20 H 8 ] 4− anion that is interconnected in the structure via N-In-N bonding. The reaction pathway of the formation of this compound is investigated by thermal analysis and the crystal structure of unique (NH 4 )[(InCl 2 ) 3 (C 12 N 20 H 8 )]· [InCl 3 (NH 3 )] is reported as well as its photoluminescence properties. The thermal deprotonation of melamine in the presence of InCl 3 leads to the novel [C 12 N 20 H 8 ] 4− tetramer, based on four melaminate ions.