Hexachloroborazine
Chemical compound
From Wikipedia, the free encyclopedia
Hexachloroborazine is an inorganic compound with the chemical formula B3Cl6N3.[1][2] This is a fully chlorinated derivative of borazine (B3N3H6), a cyclic compound often referred to as "inorganic benzene" due to its structural and electronic similarity to benzene.
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| Names | |
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| IUPAC name
2,2,4,4,6,6-hexachloro-1,3,5,2,4,6-triazatriborinane | |
Other names
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| Identifiers | |
3D model (JSmol) |
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PubChem CID |
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| Properties | |
| B3Cl6N3 | |
| Molar mass | 287.15 g·mol−1 |
| Appearance | white crystals |
| Density | g/cm3 |
| Melting point | 95 °C (203 °F; 368 K) |
| Hazards | |
| Flash point | °C |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
Hexachloroborazine features a planar, six-membered ring with alternating boron and nitrogen atoms, analogous to the carbon ring in benzene. Each boron atom is bonded to one chlorine atom, while each nitrogen atom bears a lone pair of electrons. The B–N bond lengths are approximately 1.44 Å, intermediate between single and double bonds, indicating significant π-delocalization across the ring. The molecule possesses D3h symmetry and is isoelectronic and isostructural with hexachlorobenzene (C6Cl6), though the electronic distribution differs due to the polarity of the B–N bonds.[3][4]
Synthesis
Hexachloroborazine was first prepared by thermal decomposition of dichloroborazide at 200 °C. However, this method gives low yields and is very dangerous due to the risk of explosions. A more advantageous method is the reaction of boron trichloride and nitrogen trichloride in carbon tetrachloride at 45 °C.[5]
- 3BCl3 + 3NCl3 ⟶ B3Cl6N3 + 6Cl2
Physical properties
The compound forms white powder that crystallizes in the trigonal crystal system in the space group R3.[6]
Uses
Hexachloroborazine is of interest in inorganic chemistry, materials science, and the synthesis of boron nitride-based materials.
The compound is used as a precursor to boron nitride materials—used in the synthesis of thin films, fibers, and ceramics via chemical vapor deposition (CVD) or polymer-derived ceramic (PDC) routes.[7][8]