the carbon carbon bond length in benzene is 139 pm.
the carbon carbon bond length in benzene is 139 pm.
the carbon carbon bond length in benzene is?
139 pm
comparing the two contributing structures of benzene, all single and double bonds are interchanged. bond lengths can be measured, for example using x-ray diffraction. the average length of a c–c single bond is 154 pm; that of a c=c double bond is 133 pm. in localized cyclohexatriene, the carbon–carbon bonds should be alternating 154 and 133 pm. instead, all carbon–carbon bonds in benzene are found to be about 139 pm, a bond length intermediate between single and double bond. this mixed single and double bond (or triple bond) character is typical for all molecules in which bonds have a different bond order in different contributing structures. bond lengths can be compared using bond orders. for example, in cyclohexane the bond order is 1 while that in benzene is 1 + (3 ÷ 6) = . consequently, benzene has more double bond character and hence has a shorter bond length than cyclohexane.
resonance (chemistry)
there are two forms of wc, a hexagonal form, α-wc (hp2, space group pm2, no. 187), and a cubic high-temperature form, β-wc, which has the rock salt structure. the hexagonal form can be visualized as made up of a simple hexagonal lattice of metal atoms of layers lying directly over one another (i.e. not close packed), with carbon atoms filling half the interstices giving both tungsten and carbon a regular trigonal prismatic, 6 coordination. from the unit cell dimensions the following bond lengths can be determined: the distance between the tungsten atoms in a hexagonally packed layer is 291 pm, the shortest distance between tungsten atoms in adjoining layers is 284 pm, and the tungsten carbon bond length is 220 pm. the tungsten-carbon bond length is therefore comparable to the single bond in (218 pm) in which there is strongly distorted trigonal prismatic coordination of tungsten.
tungsten carbide