215655-69-9Relevant academic research and scientific papers
Characterization of an intramolecular nonbonded interaction between selenium and fluorine in solution
Iwaoka, Michio,Komatsu, Hiroto,Tomoda, Shuji
, p. 969 - 970 (1998)
NMR measurements of JSe...F coupling constants (22.7-84.2 Hz) of o-selenobenzyl fluoride derivatives in solution provided strong evidence for weak intramolecular selenium-fluorine nonbonded interaction, in which fluorine donates electrons to selenium.
Quantitative evaluation of weak nonbonded Se···F interactions and their remarkable nature as orbital interactions
Iwaoka, Michio,Komatsu, Hiroto,Katsuda, Takayuki,Tomoda, Shuji
, p. 1902 - 1909 (2007/10/03)
To evaluate weak intramolecular nonbonded Se·"·F interactions recently characterized for a series of o-selenobenzyl fluoride derivatives (Iwaoka et al., Chem. Lett. 1998, 969-970), the temperature dependence of the nuclear spin coupling between Se and F (JSe···F) was investigated for 2-(fluoromethyl)phenylselenenyl cyanate (1a) and bis[2-(fluoromethyl)phenyl] diselenide (1e) in CD2Cl2 and CD3CN. A significant increase in the magnitude of JSe···F was observed for both 1a and 1e upon lowering temperature, whereas the values of JSe···F for the corresponding trifluoromethyl compounds slightly reduced or remained unchanged at low temperatures. Application of the rapid equilibrium model between two possible conformers revealed that conformer A with an intramolecular Se···F interaction is more stable in enthalpy (ΔH) by 1.23 kcal/mol for 1a (in CD2Cl2) and by 0.85 and 0.83 kcal/mol for 1e (in CD2Cl2 and CD3CN, respectively) than conformer B, which does not have close Se···F contact. The negligible solvent effects for 1e suggested marginal electrostatic nature of the Se···F interactions. Instead, importance of the nF → σ*Se-x orbital interaction was suggested by quantum chemical (QC) calculations and the natural bond orbital (NBO) analysis.
