116149-14-5Relevant academic research and scientific papers
Gas-Phase Electron-Transfer Equilibrium Studies on Tetraalkylhydrazines: Geometry Effects on Ionization Thermochemistry, Relaxation Energies, and Ion Solvation Energies
Nelsen, Stephen F.,Rumack, Daniel T.,Meot-Ner, Michael
, p. 7945 - 7952 (1988)
Equilibrium constants for electron-transfer equilibration between 35 pairs of tetraalkylhydrazines and their cation radicals were measured by high-pressure mass spectrometry and provided the data allowing calculation of aIP and ΔS0 of ionization for 31 tetraalkylhydrazines.Photoelectron spectroscopy measurements of vIP allow calculation of their enthalpies of relaxation, which range from a highest value of 38.3 kcal/mol for the trans-dipseudoequatorial conformation of 1,2-dimethylpyrazolidine (19) to a low of 18.9 kcal/mol for bridgehead anti-diazasesquinorbornane (30).The effects of changeing alkyl groups on both vIP and aIP are discussed.Comparison of the gas-phase equilibrium constants (extrapolated to 25 deg C) with cyclic voltammetric measurements of E0' in solution show that the enthalpy of solvation is strongest for the compounds with the smallest alkyl groups, tetramethylhydrazine (1) and (19), and about 7 kcal weaker for 30 but that the change in solvation energy correlates with the gas-phase charge-delocalizing ability of the alkyl groups and not with ease of approach of solvent molecules to the nitrogen atoms.
