Iodine

• Formula: I₂
• Molecular weight: 253.80894
• IUPAC Standard InChI: InChI=1S/I2/c1-2 Copy

  
• IUPAC Standard InChIKey: PNDPGZBMCMUPRI-UHFFFAOYSA-N Copy
• CAS Registry Number: 7553-56-2
• 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.
• Other names: I2; Eranol; Iode; Iodine-127; Iodio; Iosan Superdip; Jod; Jood; Molecular iodine; Tincture iodine; Vistarin; Iodine crystals; Iodine sublimed; Diiodine; Diatomic iodine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Reaction thermochemistry data (reactions 1 to 50)
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data: reactions 51 to 75
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
  • X-ray Photoelectron Spectroscopy Database, version 5.0
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Reaction thermochemistry data

Go To: Top, References, Notes

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:
B - John E. Bartmess
MS - José A. Martinho Simões
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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.

Reactions 1 to 50

 +  = I₃^-

By formula: I^- + I₂ = I₃^-

 (cr) +  (cr) = 2 (cr)

By formula: C₁₀Mn₂O₁₀ (cr) + I₂ (cr) = 2C₅IMnO₅ (cr)

 (cr) +  (cr) = 2 (cr)

By formula: C₁₀O₁₀Re₂ (cr) + I₂ (cr) = 2C₅IO₅Re (cr)

 +  =  + 

By formula: HI + C₃H₅I = C₃H₆ + I₂

 +  =  + 

By formula: HI + CH₃I = CH₄ + I₂

C₁₂H₁₆Nb (cr) + 2 (cr) = C₁₀H₁₀I₂Nb (cr) + 2 (l)

By formula: C₁₂H₁₆Nb (cr) + 2I₂ (cr) = C₁₀H₁₀I₂Nb (cr) + 2CH₃I (l)

C₂₀H₂₆CoN₅O₄ (solution) +  (solution) = C₁₃H₁₉CoIN₅O₄ (solution) +  (solution)

By formula: C₂₀H₂₆CoN₅O₄ (solution) + I₂ (solution) = C₁₃H₁₉CoIN₅O₄ (solution) + C₇H₇I (solution)

C₁₄H₂₂CoN₅O₄ (solution) +  (solution) = C₁₃H₁₉CoIN₅O₄ (solution) +  (solution)

By formula: C₁₄H₂₂CoN₅O₄ (solution) + I₂ (solution) = C₁₃H₁₉CoIN₅O₄ (solution) + CH₃I (solution)

 (l) +  (cr) =  (g) +  (cr)

By formula: C₅HMnO₅ (l) + I₂ (cr) = HI (g) + C₅IMnO₅ (cr)

 +  =

By formula: C₂H₄ + I₂ = C₂H₄I₂

 +  =  + 

By formula: I₂ + CClF₃ = CF₃I + ClI

 +  =  + 

By formula: HI + C₆H₁₁I = C₆H₁₂ + I₂

 +  =  + 

By formula: C₂H₃F₃ + I₂ = HI + C₂H₂F₃I

 +  =  + 

By formula: C₂H₂BrF₃ + I₂ = C₂H₂F₃I + BrI

 (l) + 2 (cr) = 2 (l) +  (cr)

By formula: C₂H₆Hg (l) + 2I₂ (cr) = 2CH₃I (l) + HgI₂ (cr)

 (solution) +  (solution) = 2 (solution)

By formula: C₁₀O₁₀Re₂ (solution) + I₂ (solution) = 2C₅IO₅Re (solution)

 (l) + 3 (cr) = GaI₃ (cr) + 3 (l)

By formula: C₃H₉Ga (l) + 3I₂ (cr) = GaI₃ (cr) + 3CH₃I (l)

 (l) + 2 (cr) = CH₃GaI₂ (cr) + 2 (l)

By formula: C₃H₉Ga (l) + 2I₂ (cr) = CH₃GaI₂ (cr) + 2CH₃I (l)

 (l) +  (cr) = 2C₃H₉ISn (l)

By formula: C₆H₁₈Sn₂ (l) + I₂ (cr) = 2C₃H₉ISn (l)

=  + 

By formula: C₄H₈I₂ = C₄H₈ + I₂

 (cr) +  (solution) =  (solution) + C₈H₅IO₃W (solution)

By formula: C₈H₆O₃W (cr) + I₂ (solution) = HI (solution) + C₈H₅IO₃W (solution)

C₁₅H₁₂MoO₃ (solution) +  (solution) = C₈H₅IMoO₃ (solution) +  (solution)

By formula: C₁₅H₁₂MoO₃ (solution) + I₂ (solution) = C₈H₅IMoO₃ (solution) + C₇H₇I (solution)

C₈H₆MoO₃ (cr) +  (solution) = C₈H₅IMoO₃ (solution) +  (solution)

By formula: C₈H₆MoO₃ (cr) + I₂ (solution) = C₈H₅IMoO₃ (solution) + HI (solution)

C₁₀MnO₁₀Re (solution) +  (solution) =  (solution) +  (solution)

By formula: C₁₀MnO₁₀Re (solution) + I₂ (solution) = C₅IO₅Re (solution) + C₅IMnO₅ (solution)

C₈H₅MoNaO₃ (solution) +  (cr) = C₈H₅IMoO₃ (solution) +  (cr)

By formula: C₈H₅MoNaO₃ (solution) + I₂ (cr) = C₈H₅IMoO₃ (solution) + INa (cr)

=  + 

By formula: C₂F₄I₂ = C₂F₄ + I₂

2 +  = 2 + 

By formula: 2C₃H₈S + I₂ = 2HI + C₆H₁₄S₂

2 +  = 2 + 

By formula: 2C₅H₁₂S + I₂ = 2HI + C₁₀H₂₂S₂

 +  = 2 + 

By formula: C₄H₁₀S₂ + I₂ = 2HI + C₄H₈S₂

 +  = 2 + 

By formula: C₈H₁₆O₂S₂ + I₂ = 2HI + C₈H₁₄O₂S₂

C₂₂H₃₆Zr (solution) + 2 (solution) = C₂₀H₃₀I₂Zr (solution) + 2 (solution)

By formula: C₂₂H₃₆Zr (solution) + 2I₂ (solution) = C₂₀H₃₀I₂Zr (solution) + 2CH₃I (solution)

 +  = 2 + 

By formula: C₃H₈S₂ + I₂ = 2HI + C₃H₆S₂

C₁₂H₁₆Zr (solution) + 2 (solution) = C₁₀H₁₀I₂Zr (solution) + 2 (solution)

By formula: C₁₂H₁₆Zr (solution) + 2I₂ (solution) = C₁₀H₁₀I₂Zr (solution) + 2CH₃I (solution)

C₂₂H₃₀O₂Zr (solution) +  (solution) = C₂₀H₃₀I₂Zr (solution) + 2 (solution)

By formula: C₂₂H₃₀O₂Zr (solution) + I₂ (solution) = C₂₀H₃₀I₂Zr (solution) + 2CO (solution)

C₂₂H₃₆Hf (solution) + 2 (solution) = C₂₀H₃₀HfI₂ (solution) + 2 (solution)

By formula: C₂₂H₃₆Hf (solution) + 2I₂ (solution) = C₂₀H₃₀HfI₂ (solution) + 2CH₃I (solution)

C₃₇H₃₀ClIrO₃P₂S (solution) +  (solution) = C₃₇H₃₀ClI₂IrOP₂ (solution) +  (solution)

By formula: C₃₇H₃₀ClIrO₃P₂S (solution) + I₂ (solution) = C₃₇H₃₀ClI₂IrOP₂ (solution) + O₂S (solution)

 +  =  + 

By formula: HI + C₇H₇I = C₇H₈ + I₂

 + 2 = 2 + 

By formula: H₂ + 2CH₃I = 2CH₄ + I₂

C₂₀H₃₂Zr (solution) +  (solution) = C₂₀H₃₀I₂Zr (solution) +  (g)

By formula: C₂₀H₃₂Zr (solution) + I₂ (solution) = C₂₀H₃₀I₂Zr (solution) + H₂ (g)

C₂₀H₃₂Hf (solution) +  (solution) = C₂₀H₃₀HfI₂ (solution) +  (g)

By formula: C₂₀H₃₂Hf (solution) + I₂ (solution) = C₂₀H₃₀HfI₂ (solution) + H₂ (g)

C₁₆H₁₀O₆W₂ (cr) +  (solution) = 2C₈H₅IO₃W (solution)

By formula: C₁₆H₁₀O₆W₂ (cr) + I₂ (solution) = 2C₈H₅IO₃W (solution)

C₁₆H₁₀Mo₂O₆ (cr) +  (solution) = 2C₈H₅IMoO₃ (solution)

By formula: C₁₆H₁₀Mo₂O₆ (cr) + I₂ (solution) = 2C₈H₅IMoO₃ (solution)

 (solution) +  (solution) = 2 (solution)

By formula: C₁₀Mn₂O₁₀ (solution) + I₂ (solution) = 2C₅IMnO₅ (solution)

 +  = ( • )

By formula: I^- + I₂ = (I^- • I₂)

 + 2 = 2 + 

By formula: H₂ + 2C₂H₅I = 2C₂H₆ + I₂

2 +  = C₆H₁₄Hg + 2

By formula: 2C₃H₇I + HgI₂ = C₆H₁₄Hg + 2I₂

2 +  = C₆H₁₄Hg + 2

By formula: 2C₃H₇I + HgI₂ = C₆H₁₄Hg + 2I₂

 +  =  + 

By formula: HI + CH₃IS = CH₄S + I₂

 +  =  + 

By formula: C₃H₆O + I₂ = HI + C₃H₅IO

 +  =  + 

By formula: I₂ + CBrF₃ = CF₃I + BrI

References

Go To: Top, Reaction thermochemistry data, Notes

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

Taylor, Asmis, et al., 1999
Taylor, T.R.; Asmis, K.R.; Zanni, M.T.; Neumark, D.M., Characterization of the I-3 radical by anion photoelectron spectroscopy, J. Chem. Phys., 1999, 110, 16, 7607-7609, https://doi.org/10.1063/1.478672 . [all data]

Do, Klein, et al., 1997
Do, K.; Klein, T.P.; Pommerening, C.A.; Sunderlin, L.S., A New Flowing Afterglow-Guided Ion Beam Tandem Mass Spectrometer. Applications to the Thermochemistry of Polyiodide Ions, J. Am. Soc. Mass Spectrom., 1997, 8, 7, 688, https://doi.org/10.1016/S1044-0305(97)00116-5 . [all data]

Finch, Gates, et al., 1977
Finch, A.; Gates, P.N.; Peake, S.J., Thermochemistry of polyhalides. III. Cesium and rubidium tetrachloroiodates, J. Inorg. Nucl. Chem., 1977, 39, 2135. [all data]

Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S., Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements, J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l . [all data]

Harel and Adamson, 1986
Harel, Y.; Adamson, A.W., J. Phys. Chem., 1986, 90, 6693. [all data]

Rodgers, Golden, et al., 1966
Rodgers, A.S.; Golden, D.M.; Benson, S.W., The thermochemistry of the gas phase equilibrium I₂ + C₃H₆ = C₃H₅I + HI, J. Am. Chem. Soc., 1966, 88, 3194-3196. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Golden, Walsh, et al., 1965
Golden, D.M.; Walsh, R.; Benson, S.W., The thermochemistry of the gas phase equilibrium I₂ + CH₄ «=» CH₃I + HI and the heat of formation of the methyl radical, J. Am. Chem. Soc., 1965, 87, 4053-4057. [all data]

Goy and Pritchard, 1965
Goy, C.A.; Pritchard, H.O., Kinetics and thermodynamics of the reaction between iodine and methane and the heat of formation of methyl iodide, J. Phys. Chem., 1965, 69, 3040-3041. [all data]

Nichol and Ubbelohde, 1952
Nichol, R.J.; Ubbelohde, A.R., A thermochemical evaluation of bond strengths in some carbon compounds. part II. Bond strengths based on the reaction CH₃I + HI = CH₄ + I₂, J. Am. Chem. Soc., 1952, 415-421. [all data]

Diogo, Simoni, et al., 1993
Diogo, H.P.; Simoni, J.A.; Minas da Piedade, M.E.; Dias, A.R.; Martinho Simões, J.A., J. Am. Chem. Soc., 1993, 115, 2764. [all data]

Toscano, Seligson, et al., 1989
Toscano, P.J.; Seligson, A.L.; Curran, M.T.; Skrobutt, A.T.; Sonnenberger, D.C., Inorg. Chem., 1989, 28, 166; ibid. 1989. [all data]

Connor, Zafarani-Moattar, et al., 1982
Connor, J.A.; Zafarani-Moattar, M.T.; Bickerton, J.; El-Saied, N.I.; Suradi, S.; Carson, R.; Al Takkhin, G.; Skinner, H.A., Organomet., 1982, 1, 1166. [all data]

Abrams and Davis, 1954
Abrams, A.; Davis, T.W., Use of radioactive iodine to determine equilibrium constants in ethylene-iodine-1,2-diiodoethane systems, J. Am. Chem. Soc., 1954, 76, 5993-59. [all data]

Cutherbertson and Kistiakowsky, 1935
Cutherbertson, G.R.; Kistiakowsky, G.B., The thermal equilibrium between ethylene iodide, ethylene and iodine, J. Chem. Phys., 1935, 3, 631-634. [all data]

Lord, Goy, et al., 1967
Lord, A.; Goy, C.A.; Pritchard, H.O., The heats of formation of trifluoromethyl chloride and bromide, J. Phys. Chem., 1967, 71, 2705-2707. [all data]

Brennan and Ubbelohde, 1956
Brennan, D.; Ubbelohde, A.R., A thermochemical evaluation of bond strengths in some carbon compounds. Part IV. Bond-strength differences based on the reaction: RI + HI = RH + I₂, where R = p-methoxyphenyl and cyclohexyl, J. Chem. Soc., 1956, 3011-3016. [all data]

Wu and Rodgers, 1974
Wu, E.; Rodgers, A.S., Thermochemistry of gas-phase equilibrium CF₃CH₃ + I₂ = CF₃CH₂I + HI. The carbon-hydrogen bond dissociation energy in 1,1,1-trifluoroethane and the heat of formation of the 2,2,2-trifluoroethyl radical, J. Phys. Chem., 1974, 78, 2315-2317. [all data]

Buckley, Ford, et al., 1980
Buckley, G.S.; Ford, W.G.F.; Rodgers, A.S., The thermochemistry of the gas phase reaction: CF₃CH₂Br + I₂ = CF₃CH₂I + IBr. Polarity effects in thermochemistry, Thermochim. Acta, 1980, 42, 349-355. [all data]

Kolesov and Papina, 1983
Kolesov, V.P.; Papina, T.S., Thermochemistry of Haloethanes, Russ. Chem. Rev., 1983, 52, 425. [all data]

Hartley, Pritchard, et al., 1950
Hartley, K.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. III.?mercury dimethyl and mercury methyl halides, Trans. Faraday Soc., 1950, 46, 1019, https://doi.org/10.1039/tf9504601019 . [all data]

Pedley and Rylance, 1977
Pedley, J.B.; Rylance, J., Computer Analysed Thermochemical Data: Organic and Organometallic Compounds, University of Sussex, Brigton, 1977. [all data]

Cox and Pilcher, 1970, 2
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds in Academic Press, New York, 1970. [all data]

Adamson, Vogler, et al., 1978
Adamson, A.W.; Vogler, A.; Kunkely, H.; Wachter, R., J. Am. Chem. Soc., 1978, 100, 1298. [all data]

Fowell and Mortimer, 1958
Fowell, P.A.; Mortimer, C.T., J. Chem. Soc., 1958, 3734.. [all data]

Pedley, Skinner, et al., 1957
Pedley, J.B.; Skinner, H.A.; Chernick, C.L., Thermochemistry of metallic alkyls. Part 8.?Tin tetramethyl, and hexamethyl distannane, Trans. Faraday Soc., 1957, 53, 1612, https://doi.org/10.1039/tf9575301612 . [all data]

Cline and Kistiakowsky, 1937
Cline, J.E.; Kistiakowsky, G.B., The gaseous equilibrium of 1,2-diiodobutane, butene-1 and iodine, J. Chem. Phys., 1937, 5, 990. [all data]

Landrum and Hoff, 1985
Landrum, J.T.; Hoff, C.D., J. Organometal. Chem., 1985, 282, 215. [all data]

Nolan, de la Vega, et al., 1988
Nolan, S.P.; de la Vega, R.L.; Mukerjee, S.L.; Gonzalez, A.A.; Zhang, K.; Hoff, C., Polyhedron, 1988, 7, 1491. [all data]

Nolan, López de la Vega, et al., 1986
Nolan, S.P.; López de la Vega, R.; Hoff, C.D., J. Organometal. Chem., 1986, 315, 187. [all data]

Wu, Pickard, et al., 1975
Wu, E.C.; Pickard, J.M.; Rodgers, A.S., Thermochemistry of the gas-phase reaction tetrafluoroethylene + iodine = 1,2-diiodoperfluoroethane. Heat of formation of 1,2-diiodoperfluoroethane and of iodoperfluoroethane, J. Phys. Chem., 1975, 79, 1078-1081. [all data]

Sunner, 1955
Sunner, S., Strain in 6,8-thioctic acid, Nature (London), 1955, 176, 217. [all data]

Schock and Marks, 1988
Schock, L.E.; Marks, T.J., J. Am. Chem. Soc., 1988, 110, 7701. [all data]

Drago, Nozari, et al., 1979
Drago, R.S.; Nozari, M.S.; Klinger, R.J.; Chamberlain, C.S., Inorg. Chem., 1979, 18, 1254. [all data]

Graham, Nichol, et al., 1955
Graham, W.S.; Nichol, R.J.; Ubbelohde, A.R., A thermochemical evaluation of bond strengths in some carbon compounds. Part III. Bond strengths based on the reactions: (a) Ph·CH₂I + HI=Ph·CH₃ + I₂ and (b) PhI + HI=PhH + I₂, J. Chem. Soc., 1955, 115-121. [all data]

Carson, Carter, et al., 1961
Carson, A.S.; Carter, W.; Pedley, J.B., The thermochemistry of reductions caused by lithium aluminium hydride I. The C-I bond dissociation energy in CH₃I, Proc. Roy. Soc. London A, 1961, 260, 550-557. [all data]

Downs and Adams, 1973
Downs, A.J.; Adams, G.J., Comprehensive Inorganic Chemistry, J. C. Bailar, H. J. Emeleus, R. Nyholm and A. F. Trotman - Dickerson, ed(s)., Pergamon Press, New York, 1973, 1543. [all data]

Ashcroft, Carson, et al., 1965
Ashcroft, S.J.; Carson, A.S.; Carter, W.; Laye, P.G., Thermochemistry of reductions caused by lithium aluminium hydride. Part 3.- The C-halogen bond dissociation energies in ethyl iodine and ethyl bromide, Trans. Faraday Soc., 1965, 61, 225-229. [all data]

Mortimer, Pritchard, et al., 1952
Mortimer, C.T.; Pritchard, H.O.; Skinner, H.A., Thermochemistry of metallic alkyls. Part V - Mercury di-propyl and mercury di-isopropyl, Trans. Faraday Soc., 1952, 48, 220-229. [all data]

Shum and Benson, 1983
Shum, L.G.S.; Benson, S.W., Thermochemnistry and kinetics of the reaction of methyl mercaptan with iodine, Int. J. Chem. Kinet., 1983, 15, 433-453. [all data]

Solly, Golden, et al., 1970
Solly, R.K.; Golden, D.M.; Benson, S.W., Thermochemical properties of iodoacetone. Intramolecular electrostatic interactions in polar molecules, J. Am. Chem. Soc., 1970, 92, 4653-4656. [all data]

Notes

Go To: Top, Reaction thermochemistry data, References

• Symbols used in this document:
  

  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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