Notes

Thus the effect of hydrogen bonding on the title compound is studied using its geometrical parameters, interaction energies, and vibrational spectra
Aromaticity and charge transfer studies have been performed to ascertain the aromatic behavior of the molecule. The PES scan studies have been done by varying the bond length to ascertain the protonation process of the compound. The IR spectral red shift (∼100 cm⁻¹), blue shift (∼97 cm⁻¹) and broadening of the polar stretching peaks shows the inter and intramolecular hydrogen bonding strength. Bond length alternation of proton donors along with the enormous interaction energies (∼0-150 kJ mol⁻¹) between the lone pair and proton donors provides clear evidence for this hydrogen bonding. The charge transfer due to the methyl substitutions which enhances the possibility of hydrogen bonding has been discussed. The main scope of this work is to study the protonation and hydrogen bonding associated with charge transfer which has great effect on the 2-amino-4, 6-dimethyl pyrimidinium hydrogen sulfate (ADHS) molecule.

Multicenter Bonding in Ditetracyanoethylene Dianion: A Simple Aromatic Picture 137, 4 Place Jussieu, 75252 Paris Cedex 05, France.Université de Paris-Sud, 91405 Orsay Cédex, France.The nature of the multicenter, long bond in ditetracyanoethylene dianion complex [TCNE]2(2-) is elucidated using high level ab initio Valence Bond (VB) theory coupled with Quantum Monte Carlo (QMC) methods. This dimer is the prototype of the general family of pancake-bonded dimers with large interplanar separations. Quantitative results obtained with a compact wave function in terms of only six VB structures match the reference CCSD(T) bonding energies. Analysis of the VB wave function shows that the weights of the VB structures are not compatible with a covalent bond between the π* orbitals of the fragments. On the other hand, these weights are consistent with a simple picture in terms of two resonating bonding schemes, one displaying a pair of interfragment three-electron σ bonds and the other displaying intrafragment three-electron π length, which is independent of the countercations but typical of three-electron importance of dynamic correlation, which is precisely the main bonding component of 3-e bonds.

Moreover, it is shown that the [TCNE]2(2-) system is topologically equivalent to the square C4H4(2-) dianion, a well-established aromatic system. To better understand the role of the cyano substituents, the unsubstituted diethylenic Na(+)2[C2H4]2(2-) complex is studied and shown to be only metastable and topologically equivalent to a rectangular C4H4(2-) dianion, devoid of Quantitative structure activity relationship for the computational prediction of University of Las Villas, Santa Clara, Villa Clara 54830, Cuba.Several nitrocompounds have been screened for carcinogenicity in rodents, but this is a lengthy and expensive process, taking two years and typically costing 2 million dollars, and uses large numbers of animals. There is, therefore, much impetus to develop suitable alternative methods. One possible way of predicting carcinogenicity is to use quantitative structure-activity relationships (QSARs). QSARs have been widely utilized for toxicity testing, thereby contributing to a reduction in the need for experimental animals. This paper describes the results of applying a TOPological substructural molecular design (TOPS-MODE) approach for predicting the rodent carcinogenicity of nitrocompounds.

The model described 790% of the experimental variance, with a standard deviation of 024. The predictive power of the model was validated by leave-one-out validation, with a determination coefficient of 066. In Organic Synthesis of 6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid , this approach enabled the contribution of different fragments to carcinogenic potency to be assessed, thereby making the relationships between structure and carcinogenicity to be transparent. It was found that the carcinogenic activity of the chemicals analysed was increased by the presence of a primary amine group bonded to the aromatic ring, a manner that was proportional to the ring aromaticity. The nitro group bonded to an aromatic carbon atom is a more important determinant of carcinogenicity than the nitro group bonded to an aliphatic carbon. Finally, the TOPS-MODE approach was compared with four other predictive models, but none of these could explain more than 66% of the variance in the carcinogenic potency with the same number of Intermicrosomal distribution of aromatizing enzyme system in equine testicular Effect of Evolution of Carbon Structure during Torrefaction in Woody Biomass on High-Quality Utilization, Institute of Urban and Rural Mining, Changzhou Torrefaction is an effective method for upgrading biomass. Cedar torrefaction is carried out in a fixed bed reactor at the temperature of 200-300 °C.

The structural parameters are obtained from elemental analysis and 13C nuclear magnetic resonance (NMR). Thermal degradation behavior of raw and torrefied cedar is monitored by thermogravimetry analysis. The results show that carbon structure varied during torrefaction has a significant effect on thermal degradation of cedar.
Website: https://notabug.org/recordrussia6