title: Intramolecular S···O chalcogen bond as stabilizing factor in geometry of substituted phenyl-SF3 molecules.
abstract: Density functional methods are used to examine the geometries and energetics of molecules containing a phenyl ring joined to the trigonal bipyramidal SF3 framework. The phenyl ring has a strong preference for an equatorial position. This preference remains when one or two ether -CH2OCH3 groups are added to the phenyl ring, ortho to SF3, wherein an apical structure lies nearly 30 kcal/mol higher in energy. Whether equatorial or apical, the molecule is stabilized by a S···O chalcogen bond, sometimes augmented by CH···F or CH···O H-bonds. The strength of the intramolecular S···O bond is estimated to lie in the range between 3 and 6 kcal/mol. A secondary effect of the S···O chalcogen bond is elongation of the S-F bonds. Solvation of the molecule strengthens the S···O interaction. Addition of substituents to the phenyl ring has only modest effects upon the S···O bond strength. A strengthening arises when an electron-withdrawing substituent is placed ortho to the ether and meta to SF3, while electron-releasing species produce an opposite effect.
authors: Department of Chemistry and Biochemistry Utah State University Logan, Utah 84322-0300, United States.
authors: Vincent de Paul N
authors: Vde P
authors: Nziko
authors: Steve
authors: S
authors: Scheiner
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D018011:Chalcogens / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D001593:Benzyl Compounds; D018011:Chalcogens