Ionhyphen;molecule reactions and vibrational deactivation ofH2plus;ions in mixtures of hydrogen and helium

摘要

Ion cyclotron resonance techniques have been used to determine the thermal energy rate constants for the ionhyphen;molecule reactions:lpar;H2plus;rpar;vplus;H2rarr;k1H3plus;plus;H,lpar;H2plus;rpar;vplus;Herarr;k2HeHplus;plus;H,rarr;kvlpar;H2plus;rpar;vprime;plus;Herarr;Heplus;plus;H2thinsp;rarr;k3HeHplus;plus;H,HeHplus;plus;H2thinsp;rarr;k4H3plus;plus;He.For a nearhyphen;Franckhyphen;Condon distribution of initial vibrational states inH2plus;thinsp;k1equals; 2.08 plusmn; 0.03,thinsp;k2equals;0.13 plusmn; 0.01, k3 0.002, andk4equals; 1.83 plusmn; 0.06times;10minus;9cm3sol;moleculemiddot; sec. Collisional deactivation of vibrationally excitedH2plus;ions is also shown to occur in nonreactive encounters with He atoms. The rate constantkngr;for this process increases with increasing vibrational quantum number ngr; and is approximately equal tok2vforH2plus;ions in vibrational state ngr;.