AlI3

aluminum iodide · aluminium triiodide

Aluminum iodide is a stable, insulating chemical compound primarily utilized as a reagent in organic synthesis.

AlI
Crystal structure of AlI3 (monoclinic, P21/c (No. 14))
Ground-state structure · Materials Project
Overview

About aluminum iodide

Aluminum iodide is a thermodynamically stable compound characterized by its insulating electronic nature. Due to its distinct chemical properties, it serves as a valuable reagent in various synthetic pathways, particularly in organic chemistry where it acts as a powerful catalyst or iodinating agent.

This material is recognized for its structural versatility, as evidenced by the significant number of reported crystal structures across major databases. Its role as a stable halide makes it an essential component in specialized industrial and laboratory applications requiring precise chemical reactivity.

At a glance

Key Properties

Cross-validated computational properties for aluminum iodide, aggregated across 3 databases.

Band Gap

3.26 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

20
3 databases, 11 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for AlI3, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
P21/c (No. 14)monoclinic3.260.0000-3.0353.73
P2/m (No. 10)Monoclinic5.11
P4/mmm (No. 123)Tetragonal4.70
Cmmm (No. 65)Orthorhombic3.60
P4/mmm (No. 123)Tetragonal7.21
Cm (No. 8)Monoclinic4.66
P1 (No. 1)Triclinic3.62
Cm (No. 8)Monoclinic7.19
P2/m (No. 10)Monoclinic7.87
P21/m (No. 11)Monoclinic4.80
C2/c (No. 15)Monoclinic5.02
P21/m (No. 11)Monoclinic5.32
Uses

Applications

Where aluminum iodide is used.

Organic synthesis catalystIodinating agentChemical manufacturing intermediate
Reference

Frequently Asked Questions

Common questions about aluminum iodide, answered from cross-validated data.

What is AlI3?

Aluminum iodide is a stable, insulating chemical compound primarily utilized as a reagent in organic synthesis.

More questions
What is AlI3 used for?
aluminum iodide (AlI3) is used in organic synthesis catalyst, iodinating agent, and chemical manufacturing intermediate.
What is the band gap of AlI3?
aluminum iodide (AlI3) has a DFT-computed band gap of 3.26 eV across 20 reported structures.
Is AlI3 a metal, semiconductor, or insulator?
With a wide band gap up to 3.26 eV it is an insulator / wide-band-gap material.
Is AlI3 thermodynamically stable?
Yes — aluminum iodide (AlI3) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of AlI3?
The lowest-energy reported polymorph of aluminum iodide (AlI3) is monoclinic symmetry, space group P21/c (No. 14).
What is the density of AlI3?
The computed density of the ground-state structure of aluminum iodide (AlI3) is 3.73 g/cm³.
How many polymorphs of AlI3 are known?
20 structures of AlI3 are reported across 3 databases, spanning 11 distinct space groups.
What elements does AlI3 contain?
aluminum iodide (AlI3) contains Al and I (2 elements).
Where does the data for AlI3 come from?
AlI3 data is cross-referenced from materials_project, mpaloe, jarvis.
Comparison

How It Compares

As a stable halide in its class, aluminum iodide functions as a critical chemical intermediate. It is distinguished by its specific reactivity profile compared to other aluminum-based halides, making it a preferred choice for targeted synthetic transformations where iodine-based chemistry is required.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • mpaloe — Data from mpaloe.
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).

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