Extension of the Unified Solvation Model to Organometallic and Polycyclic Aromatic Probes

Abstract

The unified solvation model has been extended to solvent sensitive electronic transitions in metal carbonyls and new polycyclic aromatics. The contribution from specific and nonspecific interactions is obtained. An explanation is offered for cases where the two effects go in opposite directions and cases where the electrostatic and covalent contribution go in opposite directions. The addition of these new probes leads to several new solvent S‘ values.

Solvatochromic Shift of Donor−Acceptor Substituted Bithiophene in Solvents of Different Polarity: Quantum Chemical and Molecular Dynamics Simulations

“…Donor−acceptor substituted oligothiophenes have attracted extensive experimental and theoretical interest because of their outstanding electronic and nonlinear optical properties. − Usually, the π-conjugated systems are polarized by the donor (D) and acceptor (A) substituents, resulting in stronger intramolecular charge transfer and large dipole moment. − Such D-π-A compounds may be described as a resonant form between (a) a neutral configuration, in which the central π-conjugated spacer displays a fully aromatic structure, and (b) a charge-separated form, where the central backbone takes the quinoid structure. The relative weight of these two forms depends to a large degree on the surrounding environment (e.g., the external electric field and solvent dielectric field) for a D-π-A system (cf.…”

A model based QSPR analysis of the unified non-specific solvent polarity scale

“…( 8) data set gives eqn. (10) with R 2 = 0.9185, F = 254 and an average absolute error of 0.13. SЈ = (0.67 ± 0.18) ϩ (25.77 ± 1.15)µ/MV ϩ (9.30 ± 1.77)/E HOMO-LUMO (10)…”

“…Experimental SЈ values for 67 solvents were assembled from previous publications. 5,9,10 This set included saturated and unsaturated hydrocarbons, halogenated solvents, solvents containing halogen, cyano, nitro, amide, sulfide, mercapto, sulfone, phosphate, ester, ether and carbonyl groups as well as furan, pyran, dioxane, pyridine, aniline, quinoline, imidazole, pyrrolidinone and pyrazine rings. Structures of the solvents were drawn and pre-optimized by the MMX molecular mechanics method using the PCMODEL 11 program.…”

QSPR Treatment of the Unified Nonspecific Solvent Polarity Scale

“…Experimental S ‘ data for 67 solvents (Table ) were assembled from previous publications. ,, This solvent set included saturated and unsaturated hydrocarbons, halogenated solvents, and compounds containing cyano, nitro, amide, sulfide, mercapto, sulfone, phosphate, ester, ether, and carbonyl groups and furan, pyran, dioxane, pyridine, aniline, quinoline, imidazole, pyrrolidinone, and pyrazine rings. Structures of the solvents were drawn and preoptimized by the MMX molecular mechanics method using the PCMODEL program.…”