CI4
Carbon tetraiodide · Tetraiodomethane
Carbon tetraiodide is a reactive, semiconducting carbon-iodine compound primarily used as a reagent in organic synthesis.
About Carbon tetraiodide
Carbon tetraiodide is a molecular compound consisting of a central carbon atom bonded to four iodine atoms. It is recognized for its semiconducting electronic character and is frequently utilized as a specialized reagent in organic chemical synthesis, particularly in Appel-type reactions for converting alcohols to iodides.
Due to its chemical nature, this compound is considered thermodynamically unstable relative to its constituent elements. Despite this, it remains a subject of significant interest in materials science, with numerous reported structural configurations documented across various databases.
Key Properties
Cross-validated computational properties for Carbon tetraiodide, aggregated across 4 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of CI4. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for CI4, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| I-42m (No. 121) | tetragonal | 1.12 | 0.2295 | -2.836 | 3.93 |
| — | — | 1.63 | 0.3905 | 0.385 | — |
| — | — | 0.98 | 0.4078 | 0.402 | — |
| I-42m (No. 121) | tetragonal | 0.94 | 0.5530 | 0.552 | — |
| P1 (No. 1) | triclinic | — | — | — | 3.95 |
| P1 (No. 1) | triclinic | — | — | — | 5.24 |
| P1 (No. 1) | triclinic | — | — | — | 5.62 |
| P-1 (No. 2) | triclinic | — | — | — | 8.27 |
| Cm (No. 8) | monoclinic | — | — | — | 10.15 |
| Cm (No. 8) | monoclinic | — | — | — | 7.66 |
| P1 (No. 1) | triclinic | — | — | — | 4.12 |
| I-42m (No. 121) | tetragonal | — | — | — | 6.05 |
Applications
Where Carbon tetraiodide is used.
Frequently Asked Questions
Common questions about Carbon tetraiodide, answered from cross-validated data.
What is CI4?
Carbon tetraiodide is a reactive, semiconducting carbon-iodine compound primarily used as a reagent in organic synthesis.
What is CI4 used for?
What is the band gap of CI4?
Is CI4 a metal, semiconductor, or insulator?
Is CI4 thermodynamically stable?
What is the crystal structure of CI4?
What is the density of CI4?
How many polymorphs of CI4 are known?
What elements does CI4 contain?
Where does the data for CI4 come from?
How It Compares
As a unique halogenated carbon derivative, carbon tetraiodide serves as a distinct member of the carbon-halide family. It functions as a specialized chemical reagent, differing from more common, highly stable carbon-halogen compounds by its increased reactivity and specific utility in synthetic organic chemistry.
Data sources & attribution
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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