Total geometry optimization and computation of the ab initio force
fields for cyclopropene and six of its
fluoro derivatives are carried out at the HF/6-311G* level. The
HF/6-311G*//HF/6-311G* force field of
cyclopropene is scaled using the empirical scale factors determined
only from the experimental vibrational
frequencies of the light isotopic species of cyclopropene. The
scaled force field obtained is used to calculate
the vibrational frequencies for seven deutero analogues of cyclopropene
and six of its fluoro derivatives.
The scale factors for the >CF2 moiety of
3,3-difluorocyclopropene are refined using the experimental
vibrational
frequencies of its light isotopic species. The refined set of
scale factors is transferred to the HF/6-311G*//HF/6-311G* force field of 1,2,3,3-tetrafluorocyclopropene. The
experimental vibrational frequencies of this
molecule are used to refine the scale factors for the C−F
moieties. The scale factors obtained, together
with the scale factors for cyclopropene, are used to predict the
vibrational frequencies of the 3-fluoro-, 1,3,3-trifluoro-, 1-fluoro-, and 1,2-difluorocyclopropenes. The
vibrational problems for all the molecules just
mentioned and for some of their deutero analogues are solved using the
HF/6-311G*//HF/6-311G* force
fields corrected by the corresponding refined sets of scale factors.
The complete assignments of all the
fundamental frequencies are given. Some peculiarities of the
vibrational spectra of this molecular series are
discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.