Ni(II) N-glycoside complexes of four diastereomeric monosaccharides were synthesized and analyzed by fast atom bombardment-mass spectrometry. The average kinetic energy release (KER) associated with the formation of a C 2 H 4 O 2 neutral loss was indicative of stereochemical differences in the coordinated monosaccharide. Isotopic labeling studies and various linked scanning techniques were undertaken, suggesting multiple dissociation pathways from different reacting configurations, leading to the formation of isomeric [M-C 2 H 4 O 2 ] product ions. Additionally, computational studies predict the presence of large structural differences between complexes possessing axial or equatorial C-2 substituents.