Kinetics and mechanism of the reaction between 2,3,4,5,6-pentafluorophenylacetonitrile and guanidine-like bases and the structure of the products

The reactions between the 2,3,4,5,6-pentafluorophenylacetonitrile (PFPA) and such strong N-bases as 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) have been studied by UV-vis kinetic, high-resolution LSIMS, 19F NMR and FT-IR methods. The products of these reactions (compounds 1 and 2 and oligomers) have been isolated and their structures have been studied using the methods mentioned. They have been identified as ortho or para substituted dimers and a mixture of trimers, tetramers and pentamers of PFPA. All the products are formed in a relatively slow processes described by various low equilibrium constants. The structures of the ortho or para substituted dimers have been visualized by PM5 semiempirical calculations.