13C high-resolution solid state NMR studies of the structure and dynamics of 1,6:3,4-dianhydro-2-O-tosyl-beta-D-galactopyranose.
13C CP/MAS, dipolar dephasing MAS and theoretical GIAO calculations were employed to assign 13C resonances to the molecular structure of 1,6:3,4-dianhydro-2-O-tosyl-beta-D-galactopyranose 1. From spinning sideband intensities, employing the graphical method of Herzfeld and Berger the 13C delta(ii) parameters for aromatic residue were calculated. The experimental data were compared with computed results obtained by means of the B3PW91 hybrid method and 6-311G (df, p) basis set. The X-ray geometry of 1 with the correlated position of hydrogen atoms was taken as input data for theoretical calculations. As concluded from Cambridge Crystallographic Database (CSD) search, there are two reports describing the X-ray studies of 1 that show the slightly different geometry of the compound under investigation. This work shows that such discrepancies in geometry can generate differences between computed 13C delta(ii) parameters up to 6 ppm. 13C T1 and 1H T1rho relaxation times reveal that 1 is very rigid in crystal lattice. This structure is characterized by extremely long 1H T1rho, found to be in range ca. 200 ms.
Kaźmierski
S
S
NMR Laboratory, Center of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lódz.
Olejniczak
S
S
Potrzebowski
M J
MJ
D002236:Carbohydrate Conformation; D002247:Carbon Isotopes; D005690:Galactose / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D013816:Thermodynamics
D002247:Carbon Isotopes; D005690:Galactose