Atomization energies of the gaseous molecules SbLi, Sb2Li, SbLi2, Sb2Li2, and Sb3Li determined by Knudsen effusion mass spectrometry

Abstract

Knudsen effusion mass spectrometric determination of the dissociation energy of diniobium, Nb2(g), and the heat of sublimation of solid niobiumIn the course of a systematic investigation of gaseous lithides, the species in the saturated vapor above condensed phases in the system Sb-Li have been studied. As new molecules, SbLi, Sb,Li, SbLi" Sb,Li" and Sb 3 Li were identified. Enthalpy data derived from the analysis of several gas eqUilibria led to the following atomization energies: Do·(SbLi) = (169.0± 10.0) kJ mol~'; Do·(Sb,Li) = (472.2±6.8) kJ mol~'; Do·(SbLi,) = 378.5± 10.2) kJ mol~'; Do·(Sb,Li,) = (688.8± 12.4) kJ mol~'; Do·(Sb 3 Li) = (698.2±30.0) kJ mol ~ I. These experimental atomization energies are appreciably higher than those of the corresponding compounds of lithium with bismuth. The experimental dissociation energy of SbLi is lower than predicted by Pauling'S rule as was also found for BiLi. . 5218

Structure and ionization potentials of clusters containing heavy elements

“…I I 9 II II II II II II II II II~" II II II II II II II II II T T T T I II II II II II II II II r It II II II II II II II v II II II II II II II II II II c [48] as well as Zimmerman et al [71] measured the adiabatic ionization potential and reported values less than 7.3 eV [48] and 7.46 eV [71] which are both in good agreement with our calculated value for the vertical ionization potential of 7.04eV. For the ionization potential of Sb3, several references have been found [25,47,48]. In the first reference [25], the deviation from our pseudopotential value is rather large (~ 2.7 eV).…”

“…[10,12,52,[61][62][63][64][65]72]) for As 4 (and P4) clusters. Ionization potentials are in good agreement with experimental data both for As4 [10,48,71] and Sb 4 [25,47]. The deviations are in both cases smaller than 0.3 eV.…”

“…In the first reference [25], the deviation from our pseudopotential value is rather large (~ 2.7 eV). In view of the results for the X4 clusters (X = As, Sb) where the deviations between theoretical and experimental ionization potentials are smaller by an order of magnitude (about 0" 1 eV), it is possible that the value measured for Sb3 in [25] (by Knudson effusion mass spectroscopy) refers to a state different from that considered in our calculations. The second reference [47] is nearer to our calculated value; the deviation is still about 1 eV, but it should be mentioned that measurements by electron impact ionization as done in [47] often yield too high ionization potentials [48].…”

“…In the last few years, ionization potentials of mixed clusters of alkaline atoms and antimony and tellurium, respectively, (MnXm; M = Li, Na, K, Cs; X= Sb, Te; n, m ~< 6) have been measured by mass spectroscopy [25][26][27][28] but, up to now, little is known about the structure and the type of bonding in these clusters. Pseudopotential calculations could provide considerable insight here.…”

“…For the ionization potential of Sb3, several references have been found [25,47,48]. In the first reference [25], the deviation from our pseudopotential value is rather large (~ 2.7 eV). In view of the results for the X4 clusters (X = As, Sb) where the deviations between theoretical and experimental ionization potentials are smaller by an order of magnitude (about 0" 1 eV), it is possible that the value measured for Sb3 in [25] (by Knudson effusion mass spectroscopy) refers to a state different from that considered in our calculations.…”