Experimental and Theoretical Investigation of the Reactions between Glucose and Cu⁺in the Gas Phase

Abstract

Tandem mass spectrometry was used in the analysis of Cu + -D-glucose complexes. The MIKE spectrum of these complexes generated by FAB shows that the loss of a water molecule is the most important spontaneous fragmentation, followed by a second dehydration or the loss of H 2 , whereas the metal ion Cu + is never eliminated. A theoretical survey of the potential energy surface, based on the use of density functional theory approaches, shows that the attachment of Cu + to the different basic centers of glucose induces nonnegligible bond activation phenomena within the sugar moiety. As a consequence, the cleavage of the C-O linkages of the six-membered ring leads to open complexes which are systematically much more stable than those in which the cyclic structure of the sugar is preserved. These significant stability differences reflect the preference of Cu + to yield bisligated complexes in which the metal forms almost linear arrangements with two oxygen atoms of the neutral through the participation of sd hybrids. The Cu + cation has a catalytic effect on these ring-opening mechanisms. Several pathways for the successive loss of two molecules of water can be envisaged with the origin in the cyclic and the open glucose-Cu + complexes. In general, the most stable product ions are those formed by a spontaneous fragmentation of the most stable open structures.

Fragmentation of deprotonated d-ribose and d-fructose in MALDI—Comparison with dissociative electron attachment

“…However, the m/z ratio 129 which corresponds to the loss of an H 2 O along with H 2 from the deprotonated d-ribose is observed with appreciable intensities. Loss of H 2 was observed previously in d-glucose complexed with Cu + [21], but not the loss of both H 2 and H 2 O. As discussed above, the conditions under which fragment ions are formed in ISD and PSD are very different.…”

“…collisional activation. These include studies of monosaccharides complexed with Pb 2+ [19,20], glucose with Cu + [21] and a number of trisaccharides complexed with the alkaline earth metal ions Ca 2+ and Mg 2+ [22].…”

Structure and coordination in mono and dinuclear Zn(II)-pyrrolidine dithiocarbamate complexes

“…Geometrical structures of the complexes have been optimized by the density functional B3LYP method because this functional has been found well suited for description of ion-molecule complexes, inter-and intra-molecular hydrogen bonds [22][23][24][25][26][27]. The gradient-corrected B3LYP method uses Becke's three parameter exchange functional (B3) [28] with the Lee, Yang, and Parr correlation functional (LYP) [29].…”

Sodium Ion Interactions with Aqueous Glucose: Insights from Quantum Mechanics, Molecular Dynamics, and Experiment

“…42 Previous studies also include other metal ion interactions with glucose, such as Cu + . 43 Recently, Bellesia and Gnanakaran 44 used MD simulations to examine the effect of aqueous sodium chloride on cellulose. However, to the best of our knowledge, no study has previously been published that would provide molecular-level understanding of glucose and sodium ion interactions in the aqueous phase.…”