Effect of electronegative elements on the NMR chemical shift in somesimple R-X organic compounds

In Situ Raman Study of Voltage Tolerance Up to 2.2 V of Ionic Liquid Analogue Supercapacitor Electrolytes Immune to Water Adsorption Conferred by Amphoteric Imidazole Additives

“…Due to the high electronegativity of N in IMZ, N coordinates with the H of -OH in PDO to form H-bonds, which increases species migration energy and results in a shift of the chemical shift of �CHto the high-field direction (Δδ = 0.02 and 0.06), as observed in 1 H NMR spectra in Figure 4b. 48,49 It is also supported by the corresponding chemical shift evolution of -CH 2 -in PDO (Figure S9). The shape of all signal peaks also gradually changes from sharp to broad peaks, and the peak area gradually decreases, suggesting a slower rate of H exchange in the H-bonds formed above.…”

“…With an increase in IMZ content from 0 to 5 wt %, the chemical shift of -OH in PDO shifts from 4.41 to 4.57 ppm (i.e., moving in the direction of lower field intensity with Δδ = 0.16) in 1 H NMR data (Figure a), while the chemical shift of the H corresponding to -OH in ChCl changes little, indicating that the main action site of IMZ is located in the solvent sheath of ILA 4:1 and has little effect on the chemical environment of -OH in ChCl. Due to the high electronegativity of N in IMZ, N coordinates with the H of -OH in PDO to form H-bonds, which increases species migration energy and results in a shift of the chemical shift of CH- to the high-field direction (Δδ = 0.02 and 0.06), as observed in 1 H NMR spectra in Figure b. , It is also supported by the corresponding chemical shift evolution of -CH 2 - in PDO (Figure S9). The shape of all signal peaks also gradually changes from sharp to broad peaks, and the peak area gradually decreases, suggesting a slower rate of H exchange in the H-bonds formed above.…”

Structural elucidation of dioxa‐cage compounds from tetrahydroisobenzofuran‐1(3H)‐one: analysis of NMR data and GIAO chemical shifts calculations

“…3, the C8 signal is more deshielded than C9, being the difference in their chemical shifts equal to 38.3, 28.6 and 14.2 ppm in compounds 2 , 3 and 4 , respectively. This trend is due to the electronegativity and polarizability order of the atoms attached to C9 (O > Cl > Br) and is in agreement with variations observed in similar series of substituted compounds . For the unequivocal assignment of C1, C2, C6 and C7 atoms ( δ 45.8–48.0), the analysis of HETCOR spectra (Figs S5, S10 and S15) was necessary.…”

“…This trend is due to the electronegativity and polarizability order of the atoms attached to C9 (O > Cl > Br) and is in agreement with variations observed in similar series of substituted compounds. [34][35][36] For the unequivocal assignment of C1, C2, C6 and C7 atoms (δ 45.8-48.0), the analysis of HETCOR spectra (Figs S5, S10 and S15) was necessary.…”