1N-methyl-1S-methyl-2-nitroethylene (NMSM) is an important intermediate in the synthesis of anti-ulcer drug Ranitidine. NMSM is a push pull alkene equivalent to glycine possessing both electron-donating and withdrawing nitro group at both ends of olefinic bond. The solid phase FT-IR and FT-Raman spectra of NMSM have been recorded in the region 4000-400cm and 3500-100cm, respectively. The molecu...

The determination of the energetics of the temperature-dependent two-state N $ S pseudorotational equilibrium through 3JHH analysis in 36 nucleos(t)ides and 3 abasic sugars has allowed us for the first time to quantify the strength of various nucleobase-dependent anomeric and gauche effects, and how their interplay finally steers the sugar conformation. The plots of the pDdependent thermodynami...

The Acamprosate is a significant drug for alcohol abuse therapy, which may be an effective treatment for tinnitus, too. The Acamprosate has two possible tautomers, Keto and Enol tautomers. Each of the tautomers involves two important conformers. In this work, employing density functional theory (DFT) and handling the solvent effects with the PCM model, the structural parameters, energetic behav...

The hetero Diels–Alder (HDA) reactions of 1-diethoxyphosphonyl-1,3-butadiene with various nitroso dienophiles have been studied at the B3LYP/6-31G** level. Structural, energetic and electronic properties are discussed. These cycloadditions with nitroso dienophiles are characterized by a total proximal regioselectivity and an endo selectivity. The influence of the nitroso substitution on the act...

Making use of a combination of ab initio calculated geometries, orbital energies, and orbital spatial distributions as well as experimental information about bond lengths, bond energies, vibrational frequencies, and dipole moments, the nature of the terminal PO bond in phosphates such as (MeO)(3)PO was probed and compared to the case in MeO-P=O where P is trivalent and a PO pi bond is thus assu...

Using natural bond orbital theory, aromatic stabilisation energies (NBO-ASEs) were calculated for neutral and cationic monoheterocyclic three-membered rings C2H2X(R)n (X = group 14-17 elements of rows 3-5; R F, H or SiH3; n 0-2). Generally, there was a decrease in the (anti)aromatic nature molecule moving down as either stabilizing overlap (aromaticity) destabilising interactions (antiaromatici...

In the present work, the quantum theoretical calculations of the molecular structure of the 1-(1, 3-Benzothiazol-2-yl)-3-(thiophene-5-carbonyl) thiourea has been predicted and are evaluated using Density Functional Theory (DFT) in gas phase. The geometry of the title compound was optimized by B3LYP/6-311+G and B3LYP/6-311+G* methods and the experimental geometrical parameters of the title compo...

The computer program LOBSTER (Local Orbital Basis Suite Towards Electronic-Structure Reconstruction) enables chemical-bonding analysis based on periodic plane-wave (PAW) density-functional theory (DFT) output and is applicable to a wide range of first-principles simulations in solid-state and materials chemistry. LOBSTER incorporates analytic projection routines described previously in this ver...

One-pot, four-component procedure for the synthesis of a small library of new chiral spiro- oxindolopyrrolidines with high regio-, diastereo- (>99:1 dr), and enantioselectivity (up to 80% ee) is described. In this process, the regio- and stereochemical 1,3-dipolar cycloaddition of azomethine ylides, which were generated insitu by the reaction of isatin derivatives and sarcosin,with optically ac...