Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Cyanogen iodide cation

Formula: [ICN]+ (g)

CAS RN: 34749-78-5

ATcT ID: 34749-78-5*0

SMILES: I[C+]#N

InChI: InChI=1S/CIN/c2-1-3/q+1

InChIKey: ROOIGECIGPBNMQ-UHFFFAOYSA-N

Hills Formula: C1I1N1+

2D Image:

Aliases: [ICN]+; Cyanogen iodide cation; Cyanogen iodide ion (1+); Cyanic iodide cation; Cyanic iodide ion (1+); ICN+

Relative Molecular Mass: 152.92136 ± 0.00080

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
1271.3	1271.2	± 1.7	kJ/mol

3D Image of [ICN]+ (g)

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Top contributors to the provenance of Δ_fH° of [ICN]+ (g)

The 16 contributors listed below account for 90.1% of the provenance of Δ_fH° of [ICN]+ (g).

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
44.7	2855.2	ICN (g) → I (g) + CN (g)	Δ_rH°(0 K) = 26980 ± 200 cm-1	Costen 1999, note unc2
8.2	2854.2	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.43 ± 1.0 kcal/mol	Ruscic unpub
7.1	2855.1	ICN (g) → I (g) + CN (g)	Δ_rH°(0 K) = 26580 ± 500 cm-1	Nadler 1985
6.7	2854.3	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.43 ± 1.1 kcal/mol	Ruscic unpub
5.7	2854.1	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.40 ± 1.2 kcal/mol	Ruscic unpub
3.9	2855.4	ICN (g) → I (g) + CN (g)	Δ_rH°(0 K) = 26200 ± 400 (×1.682) cm-1	Black 1990, note unc2
2.5	2856.1	ICN (g) → I+ (g) + CN (g)	Δ_rH°(0 K) = 13.679 ± 0.045 (×2.327) eV	Dibeler 1967b, AE corr, est unc
1.5	2847.2	ICN (g) + H2 (g) → HCN (g) + HI (g)	Δ_rH°(0 K) = -15.93 ± 3.1 kcal/mol	Ruscic unpub
1.5	2851.2	ICN (g) + CH4 (g) → HCN (g) + CH3I (g)	Δ_rH°(0 K) = -1.03 ± 3.1 kcal/mol	Ruscic unpub
1.4	2847.3	ICN (g) + H2 (g) → HCN (g) + HI (g)	Δ_rH°(0 K) = -15.84 ± 3.2 kcal/mol	Ruscic unpub
1.4	2851.3	ICN (g) + CH4 (g) → HCN (g) + CH3I (g)	Δ_rH°(0 K) = -0.97 ± 3.2 kcal/mol	Ruscic unpub
1.2	2847.1	ICN (g) + H2 (g) → HCN (g) + HI (g)	Δ_rH°(0 K) = -14.57 ± 3.4 kcal/mol	Ruscic unpub
1.2	2851.1	ICN (g) + CH4 (g) → HCN (g) + CH3I (g)	Δ_rH°(0 K) = -0.05 ± 3.4 kcal/mol	Ruscic unpub
0.9	2833.4	BrCN (g) + CH4 (g) → HCN (g) + CH3Br (g)	Δ_rH°(0 K) = -1.87 ± 1.0 kcal/mol	Ruscic G4
0.8	2850.2	ICN (g) + HBr (g) → BrCN (g) + HI (g)	Δ_rH°(0 K) = 5.21 ± 3.1 kcal/mol	Ruscic unpub
0.8	2850.3	ICN (g) + HBr (g) → BrCN (g) + HI (g)	Δ_rH°(0 K) = 5.20 ± 3.2 kcal/mol	Ruscic unpub

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [ICN]+ (g)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation Coefficent (%)	Species Name	Formula	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
99.8	Cyanogen iodide	ICN (g)	222.5	222.0	± 1.7	kJ/mol	152.92191 ± 0.00080	506-78-5*0
33.0	Isocyanogen iodide	INC (g)	341.7	341.9	± 4.9	kJ/mol	152.92191 ± 0.00080	66004-32-8*0
30.4	Cyanogen bromide	BrCN (g)	186.8	180.2	± 1.4	kJ/mol	105.9214 ± 0.0013	506-68-3*0
30.4	Cyanogen bromide cation	[BrCN]+ (g)	1331.3	1325.0	± 1.4	kJ/mol	105.9209 ± 0.0013	34749-77-4*0
11.4	Isocyanogen bromide	BrNC (g)	341.2	335.5	± 3.5	kJ/mol	105.9214 ± 0.0013	65997-98-0*0
9.6	Cyanogen bromide anion	[BrCN]- (g)	57.9	54.3	± 3.8	kJ/mol	105.9220 ± 0.0013	54092-05-6*0
8.4	Isocyanogen bromide anion	[BrNC]- (g)	105.1	101.9	± 4.6	kJ/mol	105.9220 ± 0.0013	238754-53-50
6.6	Isocyanogen bromide cation	[BrNC]+ (g)	1470.0	1464.3	± 5.9	kJ/mol	105.9209 ± 0.0013	238754-53-5*0
6.2	Nitrilomethyl	CN (g)	436.74	440.03	± 0.14	kJ/mol	26.01744 ± 0.00080	2074-87-5*0
4.2	Hydrogen cyanide	HCN (g)	129.685	129.301	± 0.087	kJ/mol	27.02538 ± 0.00081	74-90-8*0

Most Influential reactions involving [ICN]+ (g)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
0.996	2857.1	ICN (g) → [ICN]+ (g)	Δ_rH°(0 K) = 10.870 ± 0.001 eV	Myer 1970a
0.002	2857.2	ICN (g) → [ICN]+ (g)	Δ_rH°(0 K) = 10.87 ± 0.02 eV	Dibeler 1967b
0.000	2857.4	ICN (g) → [ICN]+ (g)	Δ_rH°(0 K) = 10.91 ± 0.02 (×2) eV	Heilbronner 1970
0.000	2857.3	ICN (g) → [ICN]+ (g)	Δ_rH°(0 K) = 10.91 ± 0.05 eV	Lake 1970, est unc

References

1		B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner, Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2		B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner, Active Thermochemical Tables: Thermochemistry for the 21^st Century. J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3		B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
5		B. Ruscic, Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables. Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
6		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.000₅ kJ/mol.

Website Functionality Credits

The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

Acknowledgement

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.