subhalide
File:Diphosphorus-tetraiodide-3D-balls.png is a subiodide of phosphorus.]]
In chemistry, subhalide usually refers to inorganic compounds that have a low ratio of halide to metal, made possible by metal–metal bonding (or element–element bonding for nonmetals), sometimes extensive. Many compounds meet this definition.{{cn|date=September 2023}}
Examples
The normal halide of boron is boron trifluoride. Boron forms many subhalides: several {{chem2|B2X4}}, including diboron tetrafluoride; also BF. Aluminium forms a variety of subhalides. For gallium, adducts of {{chem2|Ga2Cl4}} are known. Phosphorus subhalides include diphosphorus tetraiodide, {{chem2|P4Cl2}}, and {{chem2|P7Cl3}} (structurally related to {{chem2|[P7](3−)}}). For bismuth, the compound originally described as bismuth monochloride was later shown to consist of {{chem2|[Bi9](5+)}} clusters and chloride anions.{{Greenwood&Earnshaw2nd}} There are many tellurium subhalides, including tritellurium dichloride, ditellurium bromide (X = Cl, Br, I), and two forms of TeI.Zhengtao Xu "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions and Polycations" in Handbook of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium and Tellurium, Francesco Devillanova, Editor, 2006, RSC. pp. 381-416. Royal Society {{doi|10.1039/9781847557575-00455}}
References
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