9-(DIISOPROPYLAMINO)-9-AZABICYCLO[3.3.1]NONANE AND TETRAISOPROPYLHYDRAZINE - ISOLABLE RADICAL CATIONS FROM HYDRAZINES WITH NEARLY PERPENDICULAR LONE PAIRS

Cuprous iodide catalyzes the addition of isopropyl Grignard reagent to triisopropyldiazenium cation (6) to give tetraisopropylhydrazine (3), a reaction which produces mostly the hydride transfer and deprotonati on products of 6 in its absence. 9-(Dusopropylamino)-9-azabicyclo[3.3. 1]nonane (2), its 3-keto analogue (4), and 3 each give isolable radica l cations. Crystal structures are reported for 2, 2(+)NO(3)(-),3(+)OTs (-)CH(3)CN, and 4. 2(+) has its isopropyl groups in different rotamers , and 3(+) is nearly isostructural with tetraisopropylethylene (11), w ith each isopropyl methyne hydrogen roughly bisecting the C(Me(2)) uni t of an adjacent isopropyl group. The first dynamic NMR experiments re ported on radicals demonstrate that 2(+) occupies the same conformatio n in solution as in the crystal, and allow rough estimation of the bar riers for isopropyl group interconversion in 2(+) and 3(+) at similar to 11 kcal/mol. Cyclic voltammetry and photoelectron spectroscopic dat a are reported for 2 and 3.