B. Braude, A. Gatial, P. Klaeboe
Mar 1, 1990
Citations
0
Influential Citations
6
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract The vibrational spectra of 1-chloro-2,2,3,3-tetrafluoro- and 1-cyano-2,2,3,3-tetrafluorocyclobutane reveal that these compounds have a conformational equilibrium strongly shifted towards equatorial Cl and CN substituents, although to a smaller extent than for the chloro and cyanocyclobutane. When a Cl and an F atom are attached to the same carbon, they will compete for the preferred equatorial position, giving relatively small enthalpy differences between the conformers. In 1-chloro-1-fluoro-, 1-chloro-1,2,2-trifluoro- and 1,1,2-trichloro-2-3,3-trifluorocyclobutane the enthalpy differences are 2.2, 2.9 and 0.9 kJ mol −1 in the liquid, respectively. In 1-chloro-1,2,2-trifluro and 1,1,2-trichloro-2,3,3-trifluorocyclobutane the ring puckering barrier was ca. 6–7 kJ mol −1 , for the remaining compounds it was smaller than 5 kJ mol −1 .