Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules obtained by surface ionization electron impact neutralization mass spectrometry

Abstract

Ionization energies of hypervalent Li2F, Li2Cl and Na2Cl molecules detected by surface ionization electron impact neutralization mass spectrometry are reported. The ionization energies were 3.78 +/- 0.2 eV for Li2F, 4.93 +/- 0.2 eV for Li2Cl, and 4.21 +/- 0.2 eV for Na2Cl. The ionization energies (IE) agree with theoretical ionization energies calculated by ab initio methods,(1) supporting the theoretical prediction that Li2F has a hyperlithiated configuration in which the odd electron delocalizes over the two lithiums and with photoionization measurement.(2) The first ionization energy of Na2Cl was experimentally confirmed earlier(3-7) and for Li2Cl as well.(8) We have developed and used this new approach for the problem-in the present work ions were first formed by surface ionization, followed by electron attachment (neutralization).