Reversible Formation of an Inter-Molecular Compound Comprising 3ʹ-Aminofluorene-9-spiro-5ʹ-imidazolidine-2ʹ,4ʹ-dithione and Benzene

Abstract

We herein describe the synthesis of 3ʹ-aminofluorene-9-spiro-5ʹ-imidazolidine-2ʹ,4ʹ-dithione through the reaction of fluorene-9-spiro-4ʹ-thiazolidine-2ʹ,5ʹ-dithione with hydrazine, and subsequent investigation of the interactions of the synthesized spirocycle-containing imidazolidinedithione with organic solvents. Recrystallization from a solvent containing benzene led to the formation of an inter-molecular compound consisting of 3ʹ-aminofluorene-9-spiro-5ʹ-imidazolidine-2ʹ,4ʹ-dithione and benzene in a 2:1 ratio through both intramolecular N-H•••S hydrogen bonds and additional weak N-H••• interactions. The trapped benzene molecule was reversibly released by dissolution of the inter-molecular compound in acetone and subsequent concentration under reduced pressure at room temperature, and also by heating at 130-150 °C.