The relationship between 19F chemical shifts in halogenated propanes and their structures are elucidated using MNDO calculations to determine the population of rotamers. The pairs of atoms gauche to a fluorine atom and van der Waals interaction between the two terminal substituents are responsible for the 19F chemical shifts. The differences among chemical shifts in diastereomers are also discussed
Azeotrope-like compositions of dichloropentafluoropropane and
申请人:AlliedSignal Inc.
公开号:US05288819A1
公开(公告)日:1994-02-22
Azeotrope-like compositions comprising dichloropentafluoropropane and 1,2-dichloroethylene are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.