Gas‐Phase Chemistry of Ti⁺ to Zn⁺ with Butyl Isothiocyanate

Abstract

(1 3. IX.91)Using a complete set of 2H-labeled isotopomers, the gas-phase reactions of Ti' to Zn+ with butyl isothiocyanate are studied. The main product for most of the metal ions is MHNCS+ formed by an ion/dipole mechanism. Exceptions are Cr', which yields significant amounts of H, and H,S loss, Mn', which is the only ion that does not form MHNCS' at all but produces mainly C,H, and C3H6, and Zn', which predominantly reacts by charge transfer.Introduction. -Gas-phase organometallic chemistry [ 13 can be used to study the intrinsic properties of bare transition-metal ions. The absence of a solvent shell or counter ions simplifies the analysis and simultaneously makes the 'bare' ion more reactive towards bond activation. Nevertheless, the oxidative addition of, e.g., a C-H or C-C bond may be precluded by energetic reasons so that the metal ion is either completely unreactive towards the substrate or only gives rise to adduct complexes. One other possibility the metal ion has in this case, is to react by the ion/dipole mechanism [2-61.So far, we found this mechanism to be operative for several alkane derivatives C,H,,+,X; the bare metal ion abstracts the functional group of the substrate as an anion, and this results in the formation of a carbenium-ionidipole complex. Simple separation to afford CnHZn+,+ and neutral MX is in most cases endothermic, however; and thus the complex rearranges by proton transfer from the incipient carbenium ion to the metalcontaining dipole yielding a mixed complex which undergoes competitive ligand loss

Self-chemical ionization of diethylzinc

“…3 Gas-phase Zn generally reacts with neutral alkanes by charge transfer and adduct formation. [6][7][8][9][10][11] The ionization energy of the ethyl radical, C 2 H 5 Á , is 8.13 eV, 3 more than 1 eV below that of Zn. Most prior experimental studies have focused on the reactivity of bare metal cations.…”