Knowledge Bank

The salt/molecule reaction technique, which in the fast has been applied to the synthesis of small anionic species in ion pairs has been applied to the synthesis and characterization of carbanion intermediates in argon matrices. The reaction of CsF with samples of $Ar/COF2$ with M/R ratios of 1000 to 2000 gave rise to product bands at 555, 808, 930, 1039 and $1514cm-1$. All bands were very sharp, and the bands at 1039 and $1514cm-1$ were particularly intense. These bands have been assigned to the $COF3$ anion in the $Cs+COF3$ ion pair, with the band at $1514cm-1$ assignable to the carbonyl stretching mode, suggestive of lower-than-double bond character. The two bands at 930 and $1039cm-1$ are both assigned to the antisymmetric C-F stretching mode, indicating a lowering of symmetry below $C3v$ due to ion pairing in the matrix. Reactions to form the particularly chlorinated analogs have been successful as well. The reaction of CsF with several other compounds containing positive carbon centers, such as $CF3CN$ and $CF3COF$ have also yielded definite reaction products.