氮化物

化学里氮化物是一种氮的化合物 with a less 电负性元素 where nitrogen has an 氧化态 of -3。Note that there are exceptions to this naming convention, the nitrides of hydrogen, NH₃ and carbon, (CN)₂, are called ammonia and cyanogen respectively and that the nitrides of bromine, iodine are called nitrogen tribromide and nitrogen triiodide. Note that nitrogen also forms pernitrides, that contain N₂²⁻ and azides, that contain N₃⁻.
氮是具有最高电负性的元素之一，只有氧，氟和氯比它更高。这就意味着氮化物由一大组化合物构成。它们有广泛的性质和应用。

折射材料 e.g.
润滑剂 e.g. hexagonal 氮化硼, BN
切割材料 e.g. 氮化硅, Si₃N₄
绝缘体 e.g. 氮化硼, BN, 氮化硅, Si₃N₄
半导体 e.g. 氮化镓, GaN
金属镀膜 e.g. 氮化钛, TiN
hydrogen storage e.g 氮化锂, Li₃N

Classification of such a varied group of compounds is necessarily arbitrary. The following is based around their structure:

salt like, e.g. 氮化锂, Li₃N, 氮化铍, Be₃N₂
共价
- 3维结构e.g. 氮化磷, P₃N₅; boron nitride, BN
- 类钻 e.g. 氮化镓, GaN
- 分子 ("volatile") e.g. tetrasulfur tetranitride, S₄N₄
interstitial e.g. 氮化钛, TiN
intermediate e.g. 氮化铁, Fe₂N

氮化物离子

The nitride ion is N³⁻ (a nitrogen atom plus three electrons). The extra electrons give the nitrogen atom a closed inert gas shell. The nitride ion is isoelectronic with the oxide anion, O²⁻, and the fluoride anion, F⁻ and has an ionic radius estimated to be 140 pm. The nitride ion is a strong π-donor ligand, stronger than O²⁻. It forms nitrido complexes which have a short metal nitrogen bond length indicating multiple bonding.

类盐氮化物

The salt like nitrides are formed by:

the alkali metals, Li₃N, Na₃N and K₃N. Li₃N is readily formed and has a unique structure. Na₃N ^[1] and K₃N ^[2] have been synthesised by simultaneously depositing metal atoms and nitrogen atoms onto a liquid nitrogen cooled sapphire substrate. Both are unstable compounds.

the alkaline earth metals Mg₃N₂, Be₃N₂ and Ca₃N₂
the group 3 metals e.g. scandium nitride, ScN
the group 11 metals e.g. copper nitride, Cu₃N
the group 12 metals e.g. Zn₃N₂

Lithium nitride and the alkaline earth nitrides deprotonate hydrogen gas, and are rapidly hydrolysed by water to form ammonia.

共价氮化物

3 dimensional structures: These include, boron nitride silicon and phosphorus.

Diamond like nitrides: The diamond like nitrides of aluminium, gallium and indium all have the wurtzite structure in which each atom occupies tetrahedral sites. For example in aluminium nitride, each aluminium atom has four neighbouring nitrogen atoms at the corners of a tetrahedron and similarly each nitrogen atom has four neighbouring aluminium atoms at the corners of a tetrahedron. This structure is like diamond where every carbon atom occupies a tetrahedral site. Note that thallium(III) nitride, TlN is not known, whereas thallium(I) nitride, Tl₃N is.

Molecular: These include cyanogen, (CN)₂ and S₂N₂ and tetrasulfur tetranitride, S₄N₄. (Note that sulfur forms another nitride which is polymeric, (SN)_x, this is a metallic conductor and has been called a one-dimensional metal.)

间质氮化物

The interstitial nitrides are formed by transition metals where there is a sufficient difference in size between the metal atom and the nitrogen to allow the host metal lattice to accommodate the nitrogen atom. This condition is true for the group 4, 5 and 6 transition metals i.e. the Titanium, Vanadium and Chromium groups. The group 4 and 5 nitrides are refractory i.e. high melting and chemically stable.

中间态氮化物

Group 7 and 8 transition metals form nitrides that decompose readily e.g iron nitride, Fe₂N melts with decomposition at 200^oC. The precious metals are currently being investigated by a number of researchers and thin films of platinum, gold and osmium nitrides have been produced. However there is some discussion as to their structures and their properties. Platinum nitride and osmium nitride for example are now believed to contain N₂ units and as such should not be called nitrides. ^[3] ^[4]

General references

WebElements
Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements 2nd. Oxford:Butterworth-Heinemann. 1997. ISBN 0-7506-3365-4.
H.O Pierson (1996). Handbook of refractory carbides and nitrides, William Andrew Inc. ISBN 0-8155-1392-5

脚注

^ Synthesis and structure of Na₃N, Fischer, D., Jansen, M. Angew Chem Intnl 41, 10, 1755 (2002) DOI:10.1002/1521-3773(20020517)41:10<1755::AID-ANIE1755>3.0.CO;2-C
^ Synthesis and structure of K₃N, Fischer, D.; Cancarevic, Z.; Schön, J. C.; Jansen, M. Z. fur anorg allgem Chemie, 630, 1, 156, DOI: 10.1002/zaac.200300280
^ Gold film with gold nitride-A conductor but harder than gold, L. Siller, N. Peltekis, S. Krishnamurthy, Y. Chao, S.J. Bull, M.R.C. Hunt, Appl. Phys. Lett. 86, 22, 221912, (2005) DOI: 10.1063/1.1941471
^ OsN₂: Crystal structure and electronic properties, J. A. Montoya, A.D Hernandez, C. Sanloup, E Gregoryanz, S Scandolo, Appl. Phys. Lett. 90, 1, 011909 (2007) DOI: 10.1063/1.2430631

[1] Synthesis and structure of Na₃N, Fischer, D., Jansen, M. Angew Chem Intnl 41, 10, 1755 (2002) DOI:10.1002/1521-3773(20020517)41:10<1755::AID-ANIE1755>3.0.CO;2-C

[2] Synthesis and structure of K₃N, Fischer, D.; Cancarevic, Z.; Schön, J. C.; Jansen, M. Z. fur anorg allgem Chemie, 630, 1, 156, DOI: 10.1002/zaac.200300280

[3] Gold film with gold nitride-A conductor but harder than gold, L. Siller, N. Peltekis, S. Krishnamurthy, Y. Chao, S.J. Bull, M.R.C. Hunt, Appl. Phys. Lett. 86, 22, 221912, (2005) DOI: 10.1063/1.1941471

[4] OsN₂: Crystal structure and electronic properties, J. A. Montoya, A.D Hernandez, C. Sanloup, E Gregoryanz, S Scandolo, Appl. Phys. Lett. 90, 1, 011909 (2007) DOI: 10.1063/1.2430631

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