Relationships between the aqueous acidities of some carbon, oxygen, and nitrogen acids and the calculated surface local ionization energies of their conjugate bases

Computational study of the structure of dinitraminic acid, HN(NO2)2, and the energetics of some possible decomposition steps

“…Earlier we have reached a similar conclusion for aqueous HN(NO2)2, predicting its pKa to be -5.6 [18].…”

Family-independent relationships between computed molecular surface quantities and solute hydrogen bond acidity/basicity and solute-induced methanol O–H infrared frequency shifts

“…[31 (23): pi@) is the electronic density of the ith molecular orbital at the point r, ~i is its orbital energy, and p(r) is the total electronic density function. We interpret I(r) as the energy required, on average, to remove an electron from a point r in the space of an atom or molecule (23)(24)(25)(26). In particular, we have found that the positions where I(r) has its lowest values on the molecular surface, the is,,i,, are indicative of the sites that are most susceptible to charge transfer with electrophiles (23,24,26).…”

“…We interpret I(r) as the energy required, on average, to remove an electron from a point r in the space of an atom or molecule (23)(24)(25)(26). In particular, we have found that the positions where I(r) has its lowest values on the molecular surface, the is,,i,, are indicative of the sites that are most susceptible to charge transfer with electrophiles (23,24,26). For example, for a group of 40 anionic conjugate bases of carbon, oxygen, and nitrogen acids, we have shown that a very good correlation exists between the measured pK, of the acid and the calcuated is,,in of the conjugate base (24).…”

The role of the Frontier orbitals in acid–base chemistry of organic amines probed by ab initio and chemometric techniques

“…Numerous works have shown how well pK b values correlate with quantum descriptors; the average local ionization potential [35,36], atomic charges and interatomic distances [14,37], and the HOMO energy [10,13,15] are the most common quantum descriptors used.…”