Correlation constants in the chemistry of organophosphorus compounds

Abstract

Two correlation methods of ionization constants of the organophosphorus acids are discussed. The first involves application of constants characteristic of the substituents bonded to phosphorus. In the second approach the and constants found for the substituents bonded to carbon are used. The best correlations are obtained for * constants. Correlation of constants with and values employing the Taft equation gives only a fairly good correlation coefficients. Electronic effects of the substituents at phosphorus are of the same nature as those at carbon atom, but some specific difference in the resonance effects is observed probably owing to the difference betweenorand p-d or n-d overlaps. Thus the use of constants for correlation of the organophosphorus reactions is preferable.

A Quantitative Approach of the Interaction between Metal Triflates and Organic Ligands Using Electrospray Mass Spectrometry

“…In the gas phase, the LiCB order is (BuO) 3 PO (estimated) 9(PhO) 3 PO ≥(EtO) 3 PO 9(MeO) 3 PO [21]. As no steric effect is expected for 1:1 adducts of the Li + cation, the position of (PhO) 3 PO in the metal triflate scales indicates a competition between the stronger electron-withdrawing effect of the phenoxy relative to the alkoxy groups [25,26], and the larger polarizability of the phenyl relative to the smaller alkyls.…”

The Diiodine Basicity Scale: Toward a General Halogen‐Bond Basicity Scale

“…For substituents at phosphorus, a special constant, [80] s F , expresses a particular combination of s F, s a and u. For meta and para substituents of a benzene ring, which cannot act on the function by polarisability and steric effects and have moderate resonance effects, the normal substituent constant, [81] s8, often successfully measures the electronic effects.…”

Enolisation of the phosphoryl group

“…The pKoH dependence on the structure appears to be fairly complicated. With fixed Y values, e.g., Y = Ts, pKoH satisfy the Hammett correlation with o+ constants [41] (Figure 7).…”

“…Data on the effect of these groups are given in Table 8. The data are compared with u ' constants characterizing the effect of substituents at phosphorus on the acidity of phosphorus acids [41]. As seen, the content of (B) forms increases with a decrease in electronegativity of R and R'.…”