The dataset includes supporting information files for the article "Step-by-step replacement of cyano groups by tricyanovinyls – the influence on the acidity". The dataset contains results of optimization and frequency calculations carried out by Turbomole and Gaussian.

Acid-base properties are the simplest expression of compounds’ coordinating ability. In the present work, we studied in silico how the gas-phase Brønsted acidity (GA) of several polycyano substituted compounds change when cyano (CN) groups are replaced by 1,2,2-tricyanovinyl (TCNV) groups in cyanic acid, dicyanoamine, cyanoform, and hydrogen tetracyanoborate. Different tautomers and conformers/isomers are included in the study. Gas-phase acidity values are compared with the acidities of different acids, including percyanated protonated mono-carba-closo-dodecaborate (carborane acid) and dodecaborate, as well as hydrogen cyanide and 1,2,2-tricyanoethene. An estimation of acetonitrile, dimethylsufoxide, and 1,2-dichloroethane acidities are presented using the COSMO-RS method and correlational analysis. The strongest acid with four TCNV groups shows remarkable acidic properties.