Silicon tetrafluoride

Formula: F₄Si
Molecular weight: 104.0791
IUPAC Standard InChI: InChI=1S/F4Si/c1-5(2,3)4
IUPAC Standard InChIKey: ABTOQLMXBSRXSM-UHFFFAOYSA-N
CAS Registry Number: 7783-61-1
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.
Other names: Silane, tetrafluoro-; Silicon fluoride (SiF4); Tetrafluorosilane; SiF4; Silicon fluoride; UN 1859
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Reaction thermochemistry data

Go To: Top, Vibrational and/or electronic energy levels, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

+ Silicon tetrafluoride = ( • )

By formula: F^- + F₄Si = (F^- • F₄Si)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	>29.10 ± 0.50	kcal/mol	N/A	Kawamata, Neigishi, et al., 1996	gas phase; B
Δ_rH°	68.0 ± 5.0	kcal/mol	IMRB	Murphy and Beauchamp, 1977	gas phase; Fluoride Affinity: <BF₃, >iPr2BF; B
Δ_rH°	60.0 ± 4.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	54.1 ± 4.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B
Δ_rG°	51.	kcal/mol	ICR	Larson and McMahon, 1984	gas phase; switching reaction(F-)H2O, DG+-2. kcal/mol; 70 ARS/YAM; M

CN^- + Silicon tetrafluoride = (CN^- • )

By formula: CN^- + F₄Si = (CN^- • F₄Si)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	27.2 ± 1.0	kcal/mol	IMRE	Larson, Szulejko, et al., 1988	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	30.	cal/mol*K	N/A	Larson, Szulejko, et al., 1988	gas phase; switching reaction,Thermochemical ladder(CN-)H2O, Entropy change calculated or estimated; Payzant, Yamdagni, et al., 1971; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	18.30 ± 0.50	kcal/mol	IMRE	Larson, Szulejko, et al., 1988	gas phase; B,M

+ Silicon tetrafluoride = ( • )

By formula: Cl^- + F₄Si = (Cl^- • F₄Si)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	23.4 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	22.	cal/mol*K	N/A	Larson and McMahon, 1985	gas phase; switching reaction,Thermochemical ladder(Cl-)t-C4H9OH, Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	16.8 ± 2.0	kcal/mol	IMRE	Larson and McMahon, 1985	gas phase; B,M

C₆H₅NO₂^- + Silicon tetrafluoride = C₆H₅F₄NO₂Si^-

By formula: C₆H₅NO₂^- + F₄Si = C₆H₅F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	35.0 ± 2.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.50 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄FNO₂^- + Silicon tetrafluoride = C₆H₄F₅NO₂Si^-

By formula: C₆H₄FNO₂^- + F₄Si = C₆H₄F₅NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	33.0 ± 2.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.90 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄ClNO₂^- + Silicon tetrafluoride = C₆H₄ClF₄NO₂Si^-

By formula: C₆H₄ClNO₂^- + F₄Si = C₆H₄ClF₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	32.0 ± 2.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	12.00 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₇NO₂^- + Silicon tetrafluoride = C₇H₇F₄NO₂Si^-

By formula: C₇H₇NO₂^- + F₄Si = C₇H₇F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	35.0 ± 3.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.60 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

+ Silicon tetrafluoride = C₆H₄F₄O₂Si^-

By formula: C₆H₄O₂^- + F₄Si = C₆H₄F₄O₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	24.0 ± 2.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.20 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄N₂O₄^- + Silicon tetrafluoride = C₆H₄F₄N₂O₄Si^-

By formula: C₆H₄N₂O₄^- + F₄Si = C₆H₄F₄N₂O₄Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	21.0 ± 1.0	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	4.20 ± 0.60	kcal/mol	TDAs	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

F₅Si^- + Silicon tetrafluoride = F₉Si₂^-

By formula: F₅Si^- + F₄Si = F₉Si₂^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	9.6 ± 2.0	kcal/mol	IMRE	Hiraoka, Nasu, et al., 2000	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	5.13	kcal/mol	IMRE	Hiraoka, Nasu, et al., 2000	gas phase; B

C₆H₄FNO₂^- + Silicon tetrafluoride = C₆H₄F₅NO₂Si^-

By formula: C₆H₄FNO₂^- + F₄Si = C₆H₄F₅NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	12.50 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄ClNO₂^- + Silicon tetrafluoride = C₆H₄ClF₄NO₂Si^-

By formula: C₆H₄ClNO₂^- + F₄Si = C₆H₄ClF₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	11.70 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄FNO₂^- + Silicon tetrafluoride = C₆H₄F₅NO₂Si^-

By formula: C₆H₄FNO₂^- + F₄Si = C₆H₄F₅NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	12.50 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄ClNO₂^- + Silicon tetrafluoride = C₆H₄ClF₄NO₂Si^-

By formula: C₆H₄ClNO₂^- + F₄Si = C₆H₄ClF₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.60 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₇NO₂^- + Silicon tetrafluoride = C₇H₇F₄NO₂Si^-

By formula: C₇H₇NO₂^- + F₄Si = C₇H₇F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.20 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₇NO₂^- + Silicon tetrafluoride = C₇H₇F₄NO₂Si^-

By formula: C₇H₇NO₂^- + F₄Si = C₇H₇F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	15.70 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄N₂O₄^- + Silicon tetrafluoride = C₆H₄F₄N₂O₄Si^-

By formula: C₆H₄N₂O₄^- + F₄Si = C₆H₄F₄N₂O₄Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	7.20 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄N₂O₄^- + Silicon tetrafluoride = C₆H₄F₄N₂O₄Si^-

By formula: C₆H₄N₂O₄^- + F₄Si = C₆H₄F₄N₂O₄Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	8.20 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄NO₃^- + Silicon tetrafluoride = C₆H₄F₄NO₃Si^-

By formula: C₆H₄NO₃^- + F₄Si = C₆H₄F₄NO₃Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.70 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄BrNO₂^- + Silicon tetrafluoride = C₆H₄BrF₄NO₂Si^-

By formula: C₆H₄BrNO₂^- + F₄Si = C₆H₄BrF₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	11.30 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄BrNO₂^- + Silicon tetrafluoride = C₆H₄BrF₄NO₂Si^-

By formula: C₆H₄BrNO₂^- + F₄Si = C₆H₄BrF₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	11.70 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₄F₃NO₂^- + Silicon tetrafluoride = C₇H₄F₇NO₂Si^-

By formula: C₇H₄F₃NO₂^- + F₄Si = C₇H₄F₇NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.60 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₁₀H₇NO₂^- + Silicon tetrafluoride = C₁₀H₇F₄NO₂Si^-

By formula: C₁₀H₇NO₂^- + F₄Si = C₁₀H₇F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.20 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₄F₃NO₂^- + Silicon tetrafluoride = C₇H₄F₇NO₂Si^-

By formula: C₇H₄F₃NO₂^- + F₄Si = C₇H₄F₇NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	9.60 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₄N₂O₂^- + Silicon tetrafluoride = C₇H₄F₄N₂O₂Si^-

By formula: C₇H₄N₂O₂^- + F₄Si = C₇H₄F₄N₂O₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	9.20 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₈H₃F₆NO₂^- + Silicon tetrafluoride = C₈H₃F₁₀NO₂Si^-

By formula: C₈H₃F₆NO₂^- + F₄Si = C₈H₃F₁₀NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	7.30 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₈H₉NO₂^- + Silicon tetrafluoride = C₈H₉F₄NO₂Si^-

By formula: C₈H₉NO₂^- + F₄Si = C₈H₉F₄NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	19.80 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₁₃H₁₀O^- + Silicon tetrafluoride = C₁₃H₁₀F₄OSi^-

By formula: C₁₃H₁₀O^- + F₄Si = C₁₃H₁₀F₄OSi^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	22.00 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₄F₃NO₂^- + Silicon tetrafluoride = C₇H₄F₇NO₂Si^-

By formula: C₇H₄F₃NO₂^- + F₄Si = C₇H₄F₇NO₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	10.90 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₆H₄NO₃^- + Silicon tetrafluoride = C₆H₄F₄NO₃Si^-

By formula: C₆H₄NO₃^- + F₄Si = C₆H₄F₄NO₃Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	13.90 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

C₇H₄N₂O₂^- + Silicon tetrafluoride = C₇H₄F₄N₂O₂Si^-

By formula: C₇H₄N₂O₂^- + F₄Si = C₇H₄F₄N₂O₂Si^-

Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	9.50 ± 0.60	kcal/mol	IMRE	Williamson, Knighton, et al., 2001	gas phase; at 150 C; B

Vibrational and/or electronic energy levels

Go To: Top, Reaction thermochemistry data, References, Notes

Data compiled by: Takehiko Shimanouchi

Symmetry: T_d Symmetry Number σ = 12

Sym.	No	Approximate	Selected Freq.		Infrared		Raman

Species		type of mode	Value	Rating	Value	Phase	Value	Phase

a₁	1	Sym str	800	C	ia		800 S	liq.
e	2	Deg deform	268	C	ia		268 W	liq.
f₂	3	Deg str	1032	B	1031.8 S	gas	1010 W	liq.
f₂	4	Deg deform	389	B	389.35 S	gas	390 W	liq.

Source: Shimanouchi, 1972

Notes

Strong

Weak

Inactive

1~3 cm^-1 uncertainty

3~6 cm^-1 uncertainty

References

Go To: Top, Reaction thermochemistry data, Vibrational and/or electronic energy levels, Notes

Kawamata, Neigishi, et al., 1996
Kawamata, H.; Neigishi, Y.; Kishi, R.; Iwata, S.; Nakajima, A.; Kaya, K., Photoelectron Spectroscopy of Silicon-Fluorine Binary Cluster Anions (SinFm-), J. Chem. Phys., 1996, 105, 13, 5369, https://doi.org/10.1063/1.472377 . [all data]

Murphy and Beauchamp, 1977
Murphy, M.K.; Beauchamp, J.L., Methyl and Fluorine Substituent Effects on the Gas Phase Lewis Acidities of Silanes by ICR Spectroscopy, J. Am. Chem. Soc., 1977, 99, 15, 4992, https://doi.org/10.1021/ja00457a017 . [all data]

Larson and McMahon, 1985
Larson, J.W.; McMahon, T.B., Fluoride and chloride affinities of the main group oxides, fluorides, oxofluorides, and alkyls. Quantitative scales of lewis acidities from ICR halide exchange equilibria, J. Am. Chem. Soc., 1985, 107, 766. [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R., Bond dissociation energies of F2(-) and HF2(-). A gas-phase experimental and G2 theoretical study, J. Phys. Chem., 1995, 99, 7, 2002, https://doi.org/10.1021/j100007a034 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Fluoride and chloride affinities of main group oxides, fluorides, oxofluorides, and alkyls. Quantitative scales of lewis acidities from ion cyclotron resonance halide-exchange equilibria, J. Phys. Chem., 1984, 88, 1083. [all data]

Larson, Szulejko, et al., 1988
Larson, J.W.; Szulejko, J.E.; McMahon, T.B., Gas Phase Lewis Acid-Base Interactions. An Experimental Determination of Cyanide Binding Energies From Ion Cyclotron Resonance and High-Pressure Mass Spectrometric Equilibrium Measurements., J. Am. Chem. Soc., 1988, 110, 23, 7604, https://doi.org/10.1021/ja00231a004 . [all data]

Payzant, Yamdagni, et al., 1971
Payzant, J.D.; Yamdagni, R.; Kebarle, P., Hydration of CN-, NO₂-, NO₃-, and HO- in the gas phase, Can. J. Chem., 1971, 49, 3308. [all data]

Williamson, Knighton, et al., 2001
Williamson, D.H.; Knighton, W.B.; Grimsrud, E.P., Lewis acid-base interactions of SiF4 with molecular anions formed by electron capture reactions, Int. J. Mass Spectrom., 2001, 206, 1-2, 53-61, https://doi.org/10.1016/S1387-3806(00)00388-2 . [all data]

Hiraoka, Nasu, et al., 2000
Hiraoka, K.; Nasu, M.; Minamitsu, A.; Shimizu, A.; Yamabe, S., On the structure and stability of gas-phase cluster ions SiF3+(CO)(n), SiF3OH2+(SiF4)(n), SiF4H+(SiF4)(n), and F- (SiF4)(n), J. Phys. Chem. A, 2000, 104, 36, 8353-8359, https://doi.org/10.1021/jp000525d . [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

Go To: Top, Reaction thermochemistry data, Vibrational and/or electronic energy levels, References

Symbols used in this document:

Δ_rG° Free energy of reaction at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions

Δ_rS° Entropy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions

Silicon tetrafluoride

Data at NIST subscription sites:

Reaction thermochemistry data

Individual Reactions

Vibrational and/or electronic energy levels

Symmetry: Td Symmetry Number σ = 12

Notes

References

Notes

Symmetry: T_d Symmetry Number σ = 12