Comparison of nucleophilisity of n-donor ligands in interaction with Zn-TPP, SbCl BF 3 and iodine in aprotic solvents

The article examines correlations of basicity/nucleophilicity of n-donor ligands using different scales (Lewis acids are used as v-acceptors: I2, SbCl 5, BF 3, Zn-TPP, and Bronsted acid-p-fluorofenol). It is shown that in this series the Gutman donor numbers (DN) have the weakest predictability in compounds’ nucleophilic capacity. Other scales properly correlate with each other, and steric factors have little significance in coordination with iodine and n-fluorophenol. Apparently, at the moment, the most convenient is the scale of basicity/nucleophilicity of n-donor ligands, which coordinates Zn-TPP with organic compounds in chloroform. Advantages of this scale are specified. This model system allows quick determination of kinetic (K, Δλ) and thermodynamic parameters (ΔН°, ΔS 0 and ΔG 0) using electronic spectroscopy. It also helps to identify molecular complexes in the crystalline state by x-ray diffraction analysis.