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

Journal Article · Fri Oct 15 04:00:00 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), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:8; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

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