Silicon dimer

• Formula: Si₂
• Molecular weight: 56.1710
• IUPAC Standard InChI: InChI=1S/Si2/c1-2 Copy

  
• IUPAC Standard InChIKey: NTQGILPNLZZOJH-UHFFFAOYSA-N Copy
• CAS Registry Number: 12597-35-2
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
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• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to Si₂⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Peppernick, Gunaratne, et al., 2010
Peppernick, S.J.; Gunaratne, K.D.D.; Sayres, S.G.; Castleman, A.W., Photoelectron imaging of small silicon cluster anions, Si-n- (n=2-7), J. Chem. Phys., 2010, 132, 4, 044302, https://doi.org/10.1063/1.3299271 . [all data]

Arnold, Kitsopoulos, et al., 1993
Arnold, C.C.; Kitsopoulos, T.N.; Neumark, D.M., Reassignment of the Si2(-) Photodetachment Spectra, J. Chem. Phys., 1993, 99, 1, 766, https://doi.org/10.1063/1.465757 . [all data]

Nimlos, Harding, et al., 1987
Nimlos, M.R.; Harding, L.B.; Ellison, G.B., The Electronic States of Si₂ and Si₂^- as Revealed by Photoelectron Spectroscopy, J. Chem. Phys., 1987, 87, 9, 5116, https://doi.org/10.1063/1.453679 . [all data]

Mandich, Bondybey, et al., 1987
Mandich, M.L.; Bondybey, V.E.; Reents, W.D., Reactive Etching of Positive and Negative Silicon Cluster Ions by Nitrogen Dioxide, J. Chem. Phys., 1987, 86, 7, 4245, https://doi.org/10.1063/1.451885 . [all data]

Winstead, Paukstis, et al., 1995
Winstead, C.B.; Paukstis, S.J.; Walters, J.L.; Gole, J.L., Multiphoton ionization of Ag₂: Assessment of a new excited electronic state and resolution of the Ag₂ ionization potential, J. Chem. Phys., 1995, 102, 1877. [all data]

Boo and Armentrout, 1987
Boo, B.H.; Armentrout, P.B., Reaction of silicon ion (2P) with silane (SiH₄, SiD₄) heats of formation of SiHn, SiHn⁺ (n=1,2,3), and Si₂Hn⁺ (n=0,1,2,3) remarkable isotope exchange reaction involving four hydrogen shifts, J. Am. Chem. Soc., 1987, 109, 3549. [all data]

Verhaegen, Stafford, et al., 1964
Verhaegen, G.; Stafford, F.E.; Drowart, J., Mass spectrometric study of the systems boron-carbon and boron-carbon-silicon, J. Chem. Phys., 1964, 40, 1622. [all data]

Drowart, DeMaria, et al., 1958
Drowart, J.; DeMaria, G.; Inghram, M.G., Thermodynamic study of SiC utilizing a mass spectrometer, J. Chem. Phys., 1958, 29, 1015. [all data]

Notes

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• Symbols used in this document:
  

  EA	Electron affinity
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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