68738-11-4Relevant articles and documents
Complexes of carbohydrates with metal cations. XIX* the effect of the size of the cation and of the inter-oxygen distances
Angyal, Stephen J.
, p. 567 - 570 (2007/10/03)
The variation of the strength of complex formation of small polyols with cations has been examined along the series of lanthanides. The strength depends on the ionic size of the cation and on the shape and flexibility of the complexing molecule. In many cases a maximum is found around the middle of the lanthanide series. Some compounds which do not form complexes with cations separate satisfactorily on cation-exchange resin columns. More frequent use of such columns is advocated. CSIRO 2000.
Differentiation of Isomeric Camphane-2,3-diols by NMR Spectroscopy and Chemical Ionization Mass Spectrometry
Partanen, Tuula,Maelkoenen, Pentti J.,Vainiotalo, Pirjo,Vepsaelaeinen, Jouko
, p. 777 - 782 (2007/10/02)
Four diastereoisomeric camphane-2,3-diols have been synthesized and their structures verified by 1H and 13C NMR spectroscopy.Mass spectrometric differentiation of these compounds was difficult by conventional methods: the electron ionization mass spectra were almost identical, stereochemical effects were weak when NH3 and i-C4H10 were used as reagent gases in chemical ionization, and the differences apparent in the CH4 chemical ionization spectra were not easily related to the stereochemistry.Stereochemical effects were clear, however, in the collision-induced dissociation spectra of the ammonium adduct (M + NH4)+ in which ions and isomers were easily differentiated.Under chemical ionization, oxidation and/or hydride-ion abstraction reactions took place, leading to products the structure od which strongly reflected the configuration of the original diol thereby offering a further means to isomeric identification.
