Spectroscopic features of oxymethyl substituents in β-D-glucopyranosides and their characteristicity

Calculation of the structure and IR spectrum of methyl-β-D-glucopyranoside by density functional theory

“…According to the density functional theory calculation (Table 2), these vibrations had frequencies 1235 and 1403 cm -1 and higher intensities and were interpreted analogously. Thus, results obtained from calculating the isolated molecule in the middle spectral range turned out to be much worse for several analytically important bands, in contrast with previous results obtained for the quasi-isolated model [17][18][19][20]. This was apparently explained by limitations of the isolated molecule model.…”

“…These explained the characteristic changes in the spectrum on going from β-D-glucose to methyl-β-D-glucopyranoside. Subsequent application of the combined approach for calculating spectra to a large series of monosaccharides with gradually more complicated structures showed that the established spectroscopic signatures from introducing an additional hydroxylmethyl substituent [20] and other types of substituents (nitro-and epoxy-groups) [19] were characteristic. The theoretically established principles for forming spectra, in particular, structures of complicated absorption bands that relate the individual components of these bands with the location of substituents and the degree of hydroxyl substitution, explained the observed characteristic features of analytically important bands in spectra of monosaccharide derivatives.…”

Analysis of glucopyranoside trinitrate IR spectrum

“…In the range 1260-1200 cm -1 , a narrow band is observed in the spectrum of 4Me2,3,6NMe at 1226 cm -1 that is characteristic of methylglucopyranosides and, as was established from a study of the spectra of 1Me [20] and 4Me1Me [23], is a signature of an oxymethyl on C (1) . The vibration corresponding to this band with ν calc = 1220 cm -1 is highly characteristic of di-and trinitrates of methyl-β-D-glucopyranoside [16].…”

Theoretical analysis of the IR spectrum of methyl-3,4-anhydro-α-D-talohexopyranoside

“…It was noted [22][23][24] that methyl substitution of a hydroxyl H atom on C (1) in the pyranose ring produces a more resolved structure for the methylglucopyranoside spectrum in the region 1500-1200 cm -1 as compared with spectra of unsubstituted monosaccharides, where practically all bands in this region are a superposition of a large number of closely spaced absorption bands. The spectrum in the region 1500-1200 cm -1 is even more structured if the glucopyranoside contains an oxirane ring (epoxysaccharides) conjugated to the pyranose ring in addition to methyl substituents.…”

“…The results for MTHP and a comparison of them with data for methylglucopyranoside [22,23] enable the band at 1375 cm -1 in the spectrum of MTHP to be assigned to a characteristic spectral feature of the hydroxymethyl group on C (1) (ν calc = 1368 cm -1 ). Spectroscopic features of hydroxymethyl substituents in β-D-glucopyranosides were determined before [22,24]. One of them, a strong peak at 1401 cm -1 , was caused by deformation of O (1) C (1) H (1) and O (5) C (1) H (1) angles and lengthening of the C (1) -O (1) bond.…”