84600-66-8

The 13C labeled 1-decanols at positions 1, 5 and 9 have been synthesized their dynamics in (CD3O-CD2CD2)2O, CD3CD2OD, and CD2Cl2 solvents have been studied by 13C-coupled relaxation methods. The expriments were performed oin the temperature range of 245-298 K. The data were fitted using the Redfield theory of nuclear relaxation to yield dipolar spectral densities to which transformed into Cartesian correlation times. The Cartesian correlation times obtained experimentally have a strong bearing on local anisotropic motion and suggest that the size of groups attached to a given carbon and also hydrogen bonding between 1-decanol and the various solvant moleculars have a profund effect on local segmenat motion. The hydrogn bond anchoring effect is apparently strongest near the hydrogen bonding site. The effect of solvant viscoleastic response, hydrogen bonding, and torsional forcs on the motion of Cartesian modes at different locations and end-to-end vectors in l-decanol are analyzed using both generalized (GLE) and ordinary Langevin equations (OLE) simulations. The asymmetry of Cartesian correlation as one moves away from the cahin center aries from the in the torsional potentials of the C-C-C-OH and C-C-C-C linkages at each end from a hydrogen bond anchoring effect at the first (C1). The stronger retardation effect at C1 observed in ethanol is found fom the GLE simulations to be mainly attributable to a large spatial blockage of the motion of the beads near-OH. For a by solute molcules with surrounded by solvent molecules with internal rotation, its motion is closely correlated with the solvent relaxation rate giving significantly reduced friction forces. Conversely, the local Cartesian relaxation for I-decanol in methylene choloride fails to correlate effectively with solvent relaxation and can be described satusfactorily by OLEs with δ-memory kernel. The contributions from overall tumbling and internal motion to the relaxation of local Cartesian modes and to the end-to-end vectors are analyzed by using calculated apparent activation energies.

13C-Labelled carboxylic acids are readily synthesized via the reaction of organoboranes with 13C-enriched carbon monoxide; functionally substituted acids are efficiently prepared via a carbonylation-oxidation sequence.