Mass spectrometry of π-complexes of transition metals

Cyrhetrenyl chalcones: Synthesis, characterization and antimalarial evaluation

“…Whereas several cymantrenyl chalcones have been known since 1978 [34,35], the corresponding rhenium analogues (cyrhetrenyl chalcones) are practically unknown. To the best of our knowledge, only the cyrhetrenyl chalcones 2geh have been described, but their biological activity remains unreported [36].…”

Mass spectrometry of π‐complexes of transition metals. XIII—The dehydration process and genesis of ions [M–O]+⋅ in the mass spectra of cymantrenyl‐, ferrocenyl‐and benchrotrenylcarbinols

“…1) provides support for this mechanism. The subsequent elimination of water is regioselective for steric reasons, due to the proximity of hydroxyl to a-hydrogen atoms.…”

Stereochemical effect in mass spectrometry of transition metal π‐complexes

“…On the contrary, the stability of the molecular ion is higher for acyl isomers (l), which result from interaction between the trivalent iron atom and the electronegative oxygen of the carbonyl group. 3 The direct interaction of the central metal atom with the substituent of the n-ligand also give rise to the occurrence of the 'ortho-effect' in the mass spectra of arylferrocene derivatives C,H,FeC,H,C,H,R (R = 0-, m-, p-COOMe, COOEt, COOH, NH,). The [P -C,H,]+ ion peaks are present only in the mass spectra of ortho isomers, which offers a reliable analytical test to identify isomers of this type.,,, A similar regularity is observed in the case of isomeric 1,2-(a-hydroxytetramethylene)ferrocenes (3) and ferroceno [2,3]indanoles (4).…”

“…3 The direct interaction of the central metal atom with the substituent of the n-ligand also give rise to the occurrence of the 'ortho-effect' in the mass spectra of arylferrocene derivatives C,H,FeC,H,C,H,R (R = 0-, m-, p-COOMe, COOEt, COOH, NH,). The [P -C,H,]+ ion peaks are present only in the mass spectra of ortho isomers, which offers a reliable analytical test to identify isomers of this type.,,, A similar regularity is observed in the case of isomeric 1,2-(a-hydroxytetramethylene)ferrocenes (3) and ferroceno [2,3]indanoles (4). The mass spectra of endo isomers exhibit a predominance of [P -C,H,]+ ions over C,H,Fe+ owing to the stabilizing interaction of the electronegative OH group with the electron- isomers, lacking such an interaction, show high abundance of the C,H,Fe+ ion^.^^^ Therefore, the probability of processes involving simple cleavage of metal-ligand bonds in ferrocene derivatives is determined by the spatial location of the substituent in the cyclopentadienyl ring.…”