Chlorodifluoroacetyl Cyanide, ClF₂CC(O)CN: Synthesis, Structure, and Spectroscopic Characterization

Abstract

The novel molecule difluorochloroacetyl cyanide, ClF(2)CC(O)CN, has been characterized by IR (gas phase, Ar matrix), Raman (liquid), (19)F and (13)C NMR, and photoelectron (PES) spectroscopies; photoionization mass spectrometry (PIMS); and gas electron diffraction (GED). The conformational properties of ClF(2)CC(O)CN have been studied by joint application of vibrational spectroscopy, GED, and quantum chemical calculations. The existence of two conformers is detected in the gas and liquid phases, in which the C-Cl bond adopts gauche and syn orientations with respect to the C═O group. The computed enthalpy difference is in harmony with the experimental results of the gauche being more stable than the syn conformer by ΔH° = 1.3 kcal mol(-1) (MP2/cc-pVTZ). The valence electronic properties and the possible ionization and dissociation processes of the title compound are studied using the PES and PIMS. The experimental first vertical ionization energy of 12.0 eV corresponds to the ejection of an electron of the oxygen lone pairs. Taking into account the properties and broad applications of acyl cyanides, ClF(2)CC(O)CN is a promising new precursor in preparative chemistry.

Dimers of Perhaloacetyl Cyanides: CClF2C(O)OC(CN)2CClF2 and CF3C(O)OC(CN) 2CF3. Preparation, Properties, and Spectroscopy

“…(Figure S1, Supporting Information). The chemical shifts are close to those reported for similar compounds. ,, …”

“…The related 1,1-dicyanoalquil carboxilato CH 3 C(O)OC(CN) 2 CH 3 has been used, for instance, to form the widely used vinylidene cyanide through the pyrolysis of the former compound. 1 In effect, during the synthesis of CClF 2 C(O)CN 2 4 has been also characterized in the present work. Very recently, benzoyl cyanide was reported to be ideally suited for quantitative, time-resolved analysis of RNA folding and ribonucleoprotein (RNP) assembly mechanisms.…”

“…This ionization energy was also reported at 12.00 eV for the monomeric species CClF 2 C(O)CN indicating the lack of influence of the vicinal orbitals in the dimeric species. 2 The second and third ionization bands observed at 12.27 and 13.09 eV can be attributed to the process involving the chlorine lone pairs of the group CClF 2 C(O). Moreover, the calculation of these lone pairs in the group CClF 2 C(CN) 2 is computed at 13.21 eV.…”

“…The related 1,1- dicyanoalquil carboxilato CH 3 C­(O)­OC­(CN) 2 CH 3 has been used, for instance, to form the widely used vinylidene cyanide through the pyrolysis of the former compound . In effect, during the synthesis of CClF 2 C­(O)­CN from CClF 2 C­(O)Cl and AgCN a dimeric byproduct identified as CClF 2 C­(O)­OC­(CN) 2 CClF 2 was formed.…”

“…These features are assigned to a n → π* transition Figure S3 also includes the UV–vis spectrum of CClF 2 C­(O)­CN for comparison …”