PMC:2812710 / 16317-17247 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/2812710","sourcedb":"PMC","sourceid":"2812710","source_url":"https://www.ncbi.nlm.nih.gov/pmc/2812710","text":"The average values for the radii of the hydrodynamic equivalent sphere, calculated from the Stokes (5′) and Einstein (2′) relationships are also presented in Table 3. These values characterize certain external sizes of CDs molecules. When comparing these data with those measured on space-filling or CPK models (Table 1, r 0CPK = d 0/2) (Saenger 1980; Corey and Pauling 1953), it is interesting to note that (1) both kinds of radii virtually agree in water, and (2) the ratios of the hydrodynamic to the radii r 0CPK remain virtually constant in the series of studied CDs but vary in different solvents: /r 0CPK = 0.96 ± 0.03 ≅ 1.0, R DMF/r 0CPK = 1.15 ± 0.02, and R DMSO/r 0CPK = 1.41 ± 0.02. Since hydrodynamic interactions inside of CDs molecules will contribute to the friction of the molecules, different ratios of radii in different solvents may reflect not only different sizes but also different hydrodynamic interactions.","tracks":[]}