An experimental and theoretical study of the structure of Lamotrigine in its neutral and protonated forms: evidence of Lamotrigine enantiomers

A theoretical NMR study of selected benzazoles: Comparison of GIPAW and GIAO‐PCM (DMSO) calculations

“…[1][2][3][4][5] However, in previous papers, we have been successful in obtaining acceptable results using gauge-invariant atomic orbital/Becke, 3-parameter, Lee-Yang-Parr (GIAO/ B3LYP)/6-311++G(d,p) calculations together with dimethyl sulfoxide (DMSO) and polarizable continuum model (PCM; continuum solvent model). [6][7][8][9][10] Thus, establishing that DMSO is the best solvent to simulate the effects of the solid-state.…”

Theoretical study of some λ5‐phosphinines and their NMR spectra

“…In the 13 C NMR, the effect of a chlorine atom is in average −6.7 ppm (four values −4.8, −9.3, −8.2, −5.0). In the 13 C NMR, the effect of a bromine atom is in average ≈ −30 ppm …”

The structure of protonated 3-pyridyl-substituted 5-amino-1H-1,2,4-triazoles: an experimental and theoretical study

“…The absolute values of compo nents of the nuclear magnetic shielding tensor (, ppm) were transformed to the chemical shift values (, ppm) using the fol lowing empirical equation: where  13 C TMS (184.286 ppm) is the absolute value of the nuclear magnetic shielding tensor of the carbon atom of tetramethyl silane (T d symmetry) optimized by the B3LYP/6 311++G(2d,2p) method and 0.963 is an empirical correction obtained after statistical analysis of both theoretical and experi mental values of the NMR chemical shifts. 18, 19 The starting compounds 1 and 2, as well as 5 amino 3 (pyr idin 2 yl) 1,2,4 triazole hydrochloride [C 7 To a suspension of compound 1 (1.61 g, 0.01 mol) in water (4 mL), 98% sulfuric acid (0.55 g, 0.0055 mol) was added dropwise with stirring. The mixture was heated until homogenization, ethanol (5 mL) was added, and the mixture was cooled to 0-5 C.…”