Heterocyclic 1,3‐diazepine‐based thiones and selones as versatile halogen‐bond acceptors

• Published in: Acta crystallographica Section B, Structural science, crystal engineering and materials Structural science, crystal engineering and materials, 2022-10, Vol.78 (5), p.745-755
• Main Authors: Ragusa, Arianna C., Peloquin, Andrew J., Shahani, Marjan M., Dowling, Keri N., Golen, James A., McMillen, Colin D., Rabinovich, Daniel, Pennington, William T.
• Format: Article
• Language: English
• Subjects: Acetone; Acetonitrile; cocrystal; Covalent bonds; diiodine; halogen bonding; organoiodine; selone; thione
• ISSN: 2052-5206; 2052-5192; 2052-5206
• DOI: 10.1107/S2052520622008150

Utilizing the N‐heterocyclic chalcogenones hexahydro‐1,3‐bis(2,4,6‐trimethylphenyl)‐2H‐1,3‐diazepine‐2‐thione (SDiazMesS) and hexahydro‐1,3‐bis(2,4,6‐trimethylphenyl)‐2H‐1,3‐diazepine‐2‐selone (SDiazMesSe) as halogen‐bond acceptors, a total of 24 new cocrystals were prepared. The solid‐state structures of the parent molecules were also determined, along with those of their acetonitrile solvates. Through the reaction of the chalcogen atom with molecular diiodine, a variety of S—I—I and Se—I—I fragments were formed, spanning a wide range of I—I bond orders. With acetone as a reaction solvent, molecular diiodine causes the oxidative addition of acetone to the chalcogen atom, resulting in new C—S, C—Se and C—C covalent bonds under mild conditions. The common halogen‐bond donors, iodopentafluorobenzene, 1,2‐, 1,3‐ and 1,4‐diiodotetrafluorobenzene, 1,3,5‐trifluorotriiodobenzene and tetraiodoethylene resulted in halogen‐bond‐driven cocrystal formation. In most cases, the analogous SDiazMesS and SDiazMesSe cocrystals are isomorphic. Utilizing the N‐heterocyclic chalcogenones hexahydro‐1,3‐bis(2,4,6‐trimethylphenyl)‐2H‐1,3‐diazepine‐2‐thione (SDiazMesS) and hexahydro‐1,3‐bis(2,4,6‐trimethylphenyl)‐2H‐1,3‐diazepine‐2‐selone (SDiazMesSe) as halogen‐bond acceptors, 24 new cocrystals were prepared. The solid‐state structures of the parent molecules were also determined, along with those of their acetonitrile solvates.