Résumé:
-Alkali
phosphorofluoridates
(DFP)
were
prepared
by
reaction
between
phosphoryl
difluoride
oxide
P20~F4
and
alkali
fluorides.
The
caesium
salt
was
obtained
by
reaction
between
HPO2F2
and
caesium
chloride.
The
aim
was
to
establish
a
coherent
description
of
the
various
vibrational
modes
of
the
PO2F2-
ion,
so
as
to
use
it
for
more
complex
molecules
involving
either
of
the
PO2
and
PF2
groups.
For
that
purpose
a
local
symmetric
force
field
(LSFF)
was
chosen
and
good
agreement
found
between
calculated
and
observed
frequencies.
This
investigation
provided
force
constant
values
for
the
PO2F2-
ion
in
RbPO;F2,
and
enabled
us
to
test
the
transferability
of
the
force
field
to
the
DFP
whose
cristallographic
structures
are
known.
