Ehomo-values

Ehomo values are expected to be relatively more reactive compared to molecules with lower i%OM0. 

Multiple regression analysis based on Eq. 2 revealed that the cytotoxic activity mainly depended on the log P and a low Elumo value. It has been suggested that receptor protein tryptophan residues containing an aromatic ring moiety should be the best electron donor for charge transfer interactions with phenols because of their high Ehomo value [67]-... 

In both these cases, the most significant parameter was hydrophobieity. The positive coefficient with the Ehomo descriptor suggests that amines with higher Ehomo values are more easily oxidized. The lack of the indicator variable in QSAR 22 suggests that extended amines are more capable of inducing frame shift mutations TA 98 is specific for frame-shift mutations while TA 100 is specific for base pair substitution mutations. 

The actual Eox - Ehomo values range from about 2.5 to 5.0 eV below curve b, which can be explained by the effects of solvation and electron interaction [7]. The slope of the least-squares fit to the data is 0.85 eVA, which is close to the ideal value (1.0 eWN) for curve b [8]. 

A set of aliphatic compounds was used for the correlation between the activation energy and EHomo- The dataset contained acetamide, methanol, and ethanol. The regression coefficient (r2) for this relationship was 0.998. The probability of getting a correlation was 0.995 for a sample size of five. The significance of F(13) = 2610 can be ascertained by consulting the F values in distribution tables. The F(1/3)oco 005 distribution value is found to be 55.6. When the calculated F value and F distribution values are compared, it can... 

Cyclic voltammetry studies showed the ionization potential and electron affinity of each component of the molecule in solution. The HOMO and LUMO energy levels were estimated from the equations Ehomo = E x + 4.4 eV and Elumo = T 14+4.4 eV, where E(r]x and E%, were oxidation and reduction potentials with respect to the standard hydrogen electrode (SHE) and the value of 4.4 is the ionization potential for hydrogen in eV [94,95], The HOMO and LUMO energy levels of the methine dye (compound 6) (Scheme 13) were determined to be -5.82 and -3.48 eV, respectively, with respect to the vacuum level from... 

Table 7.12 Electronegativity, x> and hardness, rj (cf. Fig. 7.10). For each species x and rj have been calculated in three ways (l)From ionization energy (7) and electron affinity (4), using x = Vi(7 + A) and rj =1/2(7 - A). I and A were calculated (QCISD(T)/6-311+G ) as the energy differences of the optimized-geometry species, i.e. adiabatic values. (2) From the MP2(FC)/6-31G HOMO and LUMO, using x = — 1/2( homo + lumo) and rj = V2(Elumo — -Ehomo)- (3) From the B3LYP/6-31G Kohn-Sham HOMO and LUMO, as for (2). All the numbers refer to units of eV...

For the biotransformation assay results, concentration-normalized maximum induction values were modeled. Stepwise multiple linear regression analysis was used to select the most suitable parameters from log Kow, EHOMO, ELUMO, and the difference in EHOMO and ELUM0 (ELUM0 - EH0M0). 

Some the results of calculations are presented in Table 1 where the following designations are used E - full energy e - mean value of full energy per one carbon atom AH - heat of formation Ah - heat of formation per one mole of carbon Ehomo, Elumo - one-electron energies of highest occupied and lowest unoccupied orbitals Egap = ELUMo - EHomo - the width of forbidden gap. 

The discrepancies between the calculated values of —eHOMO and experimental ionization potentials are frequently attributed to self-interaction error. Indeed, applying the Perdew-Zunger technique4 to correct this error of the LDA-, GGA-(PBE), and meta-GGA (TPSS) functionals improves the numerical values of —8HOmo-98 Interestingly, these studies showed that the Perdew-Zunger correction does not improve ionization potentials and electron affinities if calculated as energy differences (ASCF). 

No intercept value was listed, and there were no outliers. It is of interest to note the reversal of signs for q, and Ehomo when comparing... 

The calculated energy of the highest occupied orbitals (HOMO), Ehomo, of the M015O56H22 cluster amounts to 6.1 eV. Based on general DFT theory [35] the quantity -Ehomo represents the first cluster ionization potential which converges with increasing cluster size towards the workfunction of the Mo03(010) surface. The theoretical value of -Ehomo is reasonable in view of typical work-... 

The better correlation of Ai oh with Ehomo than with values in case of organosilicon compounds adsorption may be explained by more softness of these compounds in comparison with the small organic bases. The dependencies between Aj/oh and quantum chemical indexes are presented in Fig. 2. 

The energy of the highest energy level containing electrons in the molecule. Molecules with high HOMO energy values can donate their electrons more easily compared to molecules with low HOMO energy values, and hence are more reactive. Therefore, within the validity of the Koopman s theorem, the Ehomo descriptor is related to the ionization potential IP... 

The reaction rate increases over the pH range 4-8 and indicates that SH- is the principal reactive species in solution. This pH dependence can be explained by a knowledge of EHOMO f°r eac species. Figure 2 shows the energies of the HOMO for H2S (—10.47 eV), SH" ( — 2.50eV), and S2 ( + 6.1 eV) with selected oxidants. These values are from the experimentally determined IP (Jolly, 1984) and EA values (Drzaic et al., 1984). More negative values indicate more stability and less electron-donation capability. The HOMO energies for these and other species can also be determined from the proton affinity (PA)-IP relationship... 

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