Abstract It is now established that crystalline cellulose held together not just by hydrogen bonding, but also dispersion forces and electrostatic attraction modulated stereoelectronic factors such as the exo-anomeric effect. The surface chains of native microfibrils differ in C6 conformation from therefore form different bonds, both outward inward. Dispersion forces, influenced conformation, o...

Density functional theory calculations are reported concerning the dissociative mechanism for alkene metathesis by ruthenium dichloride catalysts, including both bisphosphine and diaminocarbene/phosphine complexes. The calculations use a hierarchy of models, ranging from [(L)(PH(3))Ru(Cl)(2)(CH(2))](L=PH(3) or diaminocarbene) through the larger [(L)(PMe(3))Ru(Cl)(2)(CHPh)] to the "real"[(L)(PCy...

Ab initio calculations of the spin-spin coupling constants have been carried out for methanand ethanimine, methanaland ethanaloxime at the level of the second order polarization propagator approximation with coupled cluster singles and doubles amplitudes (SOPPA(CCSD)) using the aug-cc-pVTZ-J basis sets. Previously we have shown that this method can reproduce quantitatively the coupling constant...

We present an experimental method, which provides information on the steric and electronic properties of ligands in metal complexes. This approach is based equilibrium ion-pairing a cationic [(NHC)Ir(cod)]+ fluorescent bodipy-sulfonate (bdpSO3?). The close ion-pair [(NHC)Ir(bdpSO3)(cod)] toluene solution weakly fluorescent, but dissociates into solvent-separated ion pairs upon exposure to sligh...

An endocyclic pathway is proposed as a reaction mechanism for the anomerization from the β (1,2-trans) to the α (1,2-cis) configuration observed in glycosides carrying 2,3-trans cyclic protecting groups. This reaction occurs in the presence of a weak Lewis or Brønsted acid, while endocyclic cleavage (endocleavage) in typical glycosides was observed only when mediated by protic media or strong L...

Introduction Collagen is a fibrous protein comprising a right-handed, triple-helical bundle of three parallel, left-handed polyproline II-type helices. Each strand consists of approximately 300 repeats of the trimer (Xaa–Yaa–Gly), where Xaa is often (2S)proline (Pro) and Yaa is often (2S,4R)-4-hydroxyproline (Hyp) [1]. The most abundant protein in vertebrates, collagen is of fundamental importa...