Study of small chlorine-doped potassium clusters by thermal ionization mass spectrometry

The theoretical calculations have predicted that nonmetal-doped potassium clusters can be used in the synthesis of a new class of charge-transfer salts which can be considered as potential building blocks for the assembly of novel nanostructured material. In this work, KnCl (n?=?26) and KnCln-1 (n?=?3 and 4) clusters were produced by vaporization of a solid potassium chloride salt in a thermal ionization mass spectrometry. The ionization energies (IEs) were measured, and found to be 3.64?+/-?0.20?eV for K2Cl, 3.67?+/-?0.20?eV for K3Cl, 3.62?+/-?0.20?eV for K4Cl, 3.57?+/-?0.20?eV for K5Cl, 3.69?+/-?0.20?eV for K6Cl, 3.71?+/-?0.20?eV for K3Cl2 and 3.72?+/-?0.20?eV for K4Cl3. The KnCl+ (n?=?36) clusters were detected for the first time in a cluster beam generated by the thermal ionization source of modified design. Also, this work is the first to report experimentally obtained values of IEs for KnCl+ (n?=?36) and KnCln-1+ (n?=?3 and 4) clusters. The ionization energies for KnCl+ and KnCln-1+ clusters are much lower than the 4.34?eV of the potassium atom; hence, these clusters should be classified as superalkali species. Copyright (c) 2012 John Wiley and Sons, Ltd