Triple bond

 ( Chemical Bonding ) 

A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent bond. Triple bonds are stronger than the equivalent covalent bond or double bond, with a bond order of three. The most common triple bond is in a nitrogen N₂ molecule; the second most common is that between two carbon atoms, which can be found in . Other containing a triple bond are and . Some diatomic molecules, such as diphosphorus

and carbon monoxide, are also triple bonded. In skeletal formula the triple bond is drawn as three parallel lines (≡) between the two connected atoms. Organic Chemistry 2nd Ed. John McMurry

	acetylene, H−C≡C−H	cyanogen, N≡C−C≡N	carbon monoxide, C≡O+Chemical compounds with triple bond(s)

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Bonding Triple bonding can be explained in terms of orbital hybridization. In the case of acetylene, each carbon atom has two sp orbital and two . The two sp-orbitals are linear, with 180° bond angles, and occupy the x-axis in the cartesian coordinate system. The p-orbitals are perpendicular to the sp-orbitals on the y-axis and the z-axis. When the atoms approach each other, the sp orbitals overlap to form an sp-sp sigma bond. At the same time the p_z-orbitals approach and together they form a p_z-p_z pi-bond. Likewise, the other pair of p_y-orbitals form a p_y-p_y pi-bond. The result is formation of one sigma bond and two pi bonds.

In the bent bond, the triple bond can also formed by the overlapping of three sp³ lobes without the need to invoke a pi-bond. Advanced Organic Chemistry Carey, Francis A., Sundberg, Richard J. 5th ed. 2007

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Triple bonds between elements heavier than oxygen Many elements beyond oxygen can form triple bonds. These bonds are common in some transition metals. Hexa(tert-butoxy)ditungsten(III) and Hexa(tert-butoxy)dimolybdenum(III) are well known examples, in which the metal-metal bond distance is about 233 pm. Hexa(tert-butoxy)ditungsten(III) has attracted particular attention for its reactions with alkynes, leading to metal-carbon triple bonded compounds of the formula RC≡W(OBut)₃.

Additionally, phosphorus can exist as the highly reactive diatomic molecule diphosphorus, which has roughly half the bond-dissociation energy of dinitrogen.

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