The hydrogen abstraction reactions by OH radical from 1,1-dichloroethane and 1,2-dichloroethane have been investigated ab initio molecular orbital theory. Optimized geometries harmonic vibrational frequencies calculated for all reactants, transition structures, products at the (U)HF/6-311G(d,p) (U)MP2=full/6-311G(d,p) levels of Single point QCISD(T)/6-311G(d,p)//(U)MP2=full/6-311G(d,p) calculations also carried out inclusion higher order electron correlation. Three distinct structures...

The optimized geometries, harmonic vibrational frequencies, and energies of the cyclic structures monohydrated guanine adenine are computed using density functional theory (B3LYP) combined with 6-31+G(d,p) basis set. proton affinity O N atoms deprotonation enthalpy different NH bonds at same level theory. results compared recent data on uracil, thymine, cytosine. intrinsic acidities basicities five nucleobases discussed. Complex formation water in a moderate change pyramidal character amino...

The optimized geometries, harmonic vibrational frequencies, and energies of the three cyclic structures thymine−water complex are computed using density functional theory (B3LYP) combined with 6-31++G(d,p) basis set. proton affinity oxygen atoms deprotonation enthalpy NH bonds thymine at same level compared recent data on uracil. In both uracil thymine, enthalpies lower (1391−1449 kJ mol-1) than those biological donors peptide links (1470−1485 (Mautner, M. J. Am. Chem. Soc. 1988, 110, 3075)....

The proton affinities PA(B) of the four oxygen lone pairs and two nitrogen atoms deprotonation energies PA(A-) NH bonds uracil are calculated by density functional theory (DFT) using 6-31G(d,p) 6-31G++(d,p) basis set. PAs also abinitio MO (MP4) for comparison. DFT/B3LYP frequency shifts ν(OH) stretching vibrations with 6-31++G(d,p) three cyclic structures uracil–water complexes. usual correlations between do not hold in case closed structures. most stable complex is formed at pair...

The application of reactivity parameters derived from density functional theory in a local sense, particular the softness and Fukui function, to interpret predict mechanisms various organic reactions has been discussed. Local is shown be successful determining site-selectivity regiochemistry can used as an alternative traditional frontier orbital theory.

Reaction profile (kcal mol⁻¹) for (CF₃)₂CHOCHFO radical at the M06-2X/6-311++G(d,p) level.

Vitamin B₁ functionalised nano-ferrites: an organo-nanocatalyst for the synthesis of various spiro derivatives.

The dependence of critical micelle concentration (cmc) sodium dioctylsulfosuccinate (AOT) on the amount ethylene glycol (EG) in water + EG medium was reported to be unusual and different from that other surfactants extent cmc AOT is lower than water. It yet understood why behaves so medium, although known have some special properties. Hence present study range 0 100% (by weight) measured by using surface tension fluorescence emission methods. In contrast what reported, this revealed with...

Density functional theory has been used with different combinations of exchange and correlation functionals to study the proton affinities six organic molecules, namely H2CO, CH3CHO, CH3OH, C2H5OH, HCOOH, CH3COOH. Complete geometry optimizations have carried out for both neutral protonated species all functionals. The affinity values are then compared corresponding experimental values. It observed that combination Perdew's Becke's exchanges Proynov's is most effective in reproducing affinity.

The effect of solvent on the photoluminescence behavior luminol was studied by steady-state fluorescence spectroscopy. spectral is markedly different in polar protic solvents compared to that aprotic solvents. A quantitative estimation contribution from solvatochromic parameters, like polarizibility (π*), hydrogen-bond donor (α), and acceptor (β), made using linear free energy relationship based Kamlet−Taft equation. analysis reveals hydrogen-bond-donating ability (acidity) most important...

The homolytic C-H bond dissociation enthalpies (BDEs) of toluene and its para- meta-substituted derivatives have been estimated by using the (RO)B3LYP/6-311++G(2df,2p)//(U)B3LYP/6-311G(d,p) procedure. performance two other hybrid functionals DFT, namely, B3PWP91 O3LYP, has also evaluated same basis sets molecules. Our computed results are compared with available experimental values found to be in good agreement. (RO)B3LYP (RO)O3LYP procedures produce reliable BDEs for bonds C-X (X = F, Cl)...

Abstract The optimized geometry of isolated trimethylamine (TMA), its hydrogen bond complexes with phenol derivatives and protonated TMA is calculated at the B3LYP/6‐31++G(d,p) level. A natural orbital (NBO) analysis on these systems carried out same level theory. In TMA, one CH in each three CH 3 groups more elongated than two other ones. As revealed by NBO data, this results from a hyperconjugative interaction N lone pair to σ*(CH) orbitals bonds being transoid position respect pair....

Theoretical calculations have been carried out using ab initio MP2 and B3LYP density functional methods to investigate the interaction between fluorinated dimethyl ethers (nF = 1−5) water. Depending on number of F atoms implanted ethers, linear structures stabilized by intermolecular OwHw···O or CH···Ow hydrogen bonds closed involving both are formed. Binding energies hydrogen-bonded complexes range 4 12 kJ mol−1. Blue shifts CH stretching vibrations predicted even in absence a direct CH···O...

Abstract The structures and binding energies of complexes between substituted carbonyl bases water are the B3LYP/6‐311++G(d,p) computational level. calculations also include proton affinity (PA) O CO group, deprotonation enthalpies (DPE) CH bonds along a natural bond orbital analysis. reveal that stable open CO···H w as well cyclic CH···O H ···OC formed. for linearly related to PAs, whereas depend on both PA DPE. Different indicators hydrogen strength such electron charge density,...

Ab initio calculation at the MP2/aug-cc-pVTZ level has been performed on π-hole based N… Si tetrel bonded complexes between substituted pyridines and H2 SiO. The primary aim of study is to find out effect substitution strength nature this bond, its similarity/difference with C bond. Correlation bond several molecular properties Lewis acid (H2 SiO) base (pyridines) are explored. analyzed using AIM, NBO, symmetry-adapted perturbation theory calculations. characterized short intermolecular...