Acceptor parameter

Parameters marked with derive from an alcohol donor and an acid (C = 0) acceptor. Parameters marked with derive from a carboxyl(-OH) donor and carboxyl (C=0) acceptor (intermolecular). Entries not marked represent inverted relations. b For compound designation see Table 11. e No hydrogen atomic positions were determined for these sites. 

Murray, J. S., S. Ranganathan, and P. Politzer. 1991. Correlations Between the Solvent Hydrogen Bond Acceptor Parameter (3 and the Calculated Molecular Electrostatic Potential. J. Org. Chem. 56, 3734. 

P Kamlet-Taft hydrogen bond acceptor parameter... 

A charge transfer acceptor parameter which takes the value 1 when the substituent can act as a charge transfer acceptor and 0 when it cannot. 

Explosive Stimulus Transfer. Under a program to develop a technique to compute probability of detonation transfer between a donor and an acceptor, experiments were performed to measure the effects of seven variables. These included two donor parameters fragment slack energy and five acceptor parameters confinement, closure thickness, explosive material, explosive particle size and closure material... 

The experimental method consisted primarily of varying a single donor or acceptor parameter, and altering the air gap between the two until an approx 50% fire di stance was obtd... 

Giese et al. [48] have compiled a list of y+ and y values for a variety of clay minerals. Smectites, vermiculites, and micas tend to be very hydrophilic, with y > 28mJ/m2 and with a sizable electron acceptor parameter as well (y+ > 1 mJ/m2). Illites, on the other hand, were reported to be moderately hydrophobic (y varied from 14 to 19mJ/m2) and tended to have y+ — 0. 

Ea and Ca are empirical acceptor parameters and Eb and Cb are empirical donor parameters. The E parameters are measures of the tendency of an acid or a base to participate in electrostatic interactions, while the C parameters are measures of their tendency to form covalent bonds. 

An alternative approach uses the polarity index, P proposed by Snyder. This is based upon experimentally determined gas chromatographic retention of three test solvents on a large number of stationary phases. The test solvents selected are ethanol, 1,4-dioxane and nitromethane. As well as an overall polarity index (P), three other parameters are calculated, Xe (a proton acceptor parameter), xproton donor parameter) and x (a strong dipole parameter). 

Linear relationships between quantum chemical indexes (maximum negative (q ax) and positive (q x) charges) as well as energies of highest occupied molecular orbital (Ehomo = IP) where IP is the vertical ionization potential) and lowest unoccupied molecular orbital (Elumo) find the empirical donor-acceptor parameters of organic molecules were established in [49]. Parameters of the relationships are presented in Table 1. 

Parameters of linear equations Y = A X -)- B connecting empirical donor- acceptor parameters of organic molecules (Y) (Eqs. 24 and 25) with their quantum chemical indexes (X) from [49]... 

Empirical donor-acceptor parameter Quantum chemical index A B Mean square deviation Number of compounds... 

Simple linear relationships developed between the quantum chemical indexes of organic molecules (their maximum charges and energies of the frontier orbitals) and their empirical donor acceptor parameters as well as the heats of the hydrogen-bonded complexes formation with silica surface OH groups or the chemisorption activation energies on this surface may be used for estimation of the complexes stability and reactivity of organic compounds towards Bronsted sites of other oxide surfaces. The electron donor ability of... 

Murray, J.S., Ranganathan, S. and Politzer, P. (1991) Correlations between the solvent hydrogen bond acceptor parameter p and the calculated molecular electrostatic potential./. Org. Chcm., 56,3734—3737. 

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