Determination of consecutive bond energies by photoionization of SbH[sub [ital n]] ([ital n]=1--3)

Journal Article · Fri Oct 15 00:00:00 EDT 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465937· OSTI ID:6389916

Ruscic, B; Berkowitz, J ^[1]

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1. Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

A photoionization mass spectrometric study of SbH[sub 3] is presented. The adiabatic ionization potential (IP) of SbH[sub 3] is [le]9.40[plus minus]0.02 eV. The lowest energy fragment ion, SbH[sup +] (+H[sub 2]), has an appearance potential (0 K) of 9.73[sub 0][plus minus]0.00[sub 8] eV, while SbH[sub 2][sup +] has an AP of 11.66[plus minus]0.02 eV. The transient species SbH[sub 2] and SbH are generated [ital in] [ital situ] by reacting F atoms with SbH[sub 3]. The IP of SbH[sub 2], forming SbH[sub 2][sup +] ([ital X] [sup 1][ital A][sub 1]), is 8.731[plus minus]0.012 eV. The IP of SbH ([ital X] [sup 3][Sigma][sup [minus]],0[sup +]) to form SbH[sup +] ([ital X] [sup 2][Pi][sub 1/2]) is probably 8.753[plus minus]0.009 eV, but certainly [lt]8.79 eV. Autoionizing structure in the photoion yield curve of SbH[sup +] (SbH) is interpreted as Rydberg series converging to SbH[sup +] ([ital a] [sup 4][Sigma][sup [minus]]), which appears to be split into 1/2 and 3/2 components, with IP's of 10.843[plus minus]0.011 eV and 10.866[plus minus]0.011 eV. The difference in IP's (Sb--SbH, SbH--SbH[sub 2]) appears to conform to the extended Goddard--Harding model, when adjusted for spin--orbit splittings. The derived heats of formation are [Delta][ital H][sub [ital f]]0[sup 0](SbH)=59.1[plus minus]0.3 kcal/mol and [Delta][ital H][sub [ital f]]0[sup 0](SbH[sub 2])=52.5[plus minus]0.6 kcal/mol. These values lead to [ital D][sub 0](SbH)=56.4[plus minus]1.0, [ital D][sub 0](HSb--H)=58.3[plus minus]0.6, [ital D][sub 0](H[sub 2]Sb--H)=67.5[plus minus]0.5 (in kcal/mol). The differences in successive bond energies, 1.9[plus minus]1.2 and 9.2[plus minus]0.8 kcal/mol, depart significantly from the constant value (4.44 kcal/mol) predicted by the Goddard--Harding model. A rationalization is presented, that incorporates relativistic effects.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6389916
• Journal Information: Journal of Chemical Physics; (United States), Vol. 99:8; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANTIMONY HYDRIDES
BINDING ENERGY
AUTOIONIZATION
FORMATION HEAT
IONIZATION POTENTIAL
L-S COUPLING
MASS SPECTROSCOPY
PHOTOIONIZATION
RELATIVISTIC RANGE
RYDBERG STATES
ANTIMONY COMPOUNDS
COUPLING
ENERGY
ENERGY LEVELS
ENERGY RANGE
ENTHALPY
EXCITED STATES
HYDRIDES
HYDROGEN COMPOUNDS
INTERMEDIATE COUPLING
IONIZATION
PHYSICAL PROPERTIES
REACTION HEAT
SPECTROSCOPY
THERMODYNAMIC PROPERTIES
664400* - Experimentally Derived Information on Atomic & Molecular Properties- (1992-)
664100 - Theory of Electronic Structure of Atoms & Molecules- (1992-)