Tracing a Common “Origin” of Phase Transformation, Polymorphism, Disorder, Isosterism, and Isostructuralism in Fluorobenzoylcarvacryl Thiourea

The terms phase transformation, polymorphism, disorder, isosterism, and isostructuralism are often the keywords used in the design and engineering of molecular crystals. Three benzoylcarvacryl thiourea derivatives with [-NH–C­(S)–NH–C­(O)-] cores generate molecular crystals, which provide the basis for exploring a common link between the structures related by aforementioned terms. The apparent “origin” of all these structural modifications has been traced to the formation of a planar molecular dimeric chain built with homomeric R₂²(12) and R₂²(8) synthons occurring in tandem, one formed with N–H···O and the other with N–H···S hydrogen bonds.