The Structure of Benzene

Cooper D L, J Gerratt and M Raimondi 1986. The Electronic Structure of the Benzene Molecule. Nature 323 699-701. 

Levine A A, AG Cole (1932) The ozonides of ortho-xylene and the structure of the benzene ring. J Am Chem Soc 54 338-341. 

The structures of the benzene/Br2 and toluene/Br2 complexes at 123 K show over-the-rim coordination with hapticities varying from about 1.5... 

Hobza, P., H. L. Selzle, and E. W. Schlag. 1990. Floppy Structure of the Benzene Dimer Ab Initio Calculation on the Structure and Dipole Moment. ... 

Figure 5.49 The structure of the benzene-chromiumtricarbonyl CT complex (C3 symmetry).

The Structure of the Benzene Nucleus. Pt. II. Synthetic Formation of the Bridged Modification of the Nucleus."... 

Figure 8.2 The structure of the benzene hydrogenation catalyst [HtRurfCgHg ]2"1"...

Poro-xylene is an industrially important petrochemical. It is the precursor chemical for polyester and polyethylene terephthalate. It usually is found in mixtures containing all three isomers of xylene (ortho-, meta-, para-) as well as ethylbenzene. The isomers are very difficult to separate from each other by conventional distillation because the boiling points are very close. Certain zeoHtes or mol sieves can be used to preferentially adsorb one isomer from a mixture. Suitable desorbents exist which have boiling points much higher or lower than the xylene and displace the adsorbed species. The boihng point difference then allows easy recovery of the xylene isomer from the desorbent by distillation. Because of the basic electronic structure of the benzene ring, adsorptive separations can be used to separate the isomers of famihes of substituted aromatics as weU as substituted naphthalenes. 

AUGUST KEKULE HIT UPON THE STRUCTURE OF THE BENZENE MOLECULE IN A DREAM. A SNAKE SEEMED TO WHIRL IN A RING BEFORE HIS EYES. BY ARRANGING THE SIX CARBON ATOMS IN A RING, THE PROBLEM WAS SOLVED. 

The structures of the benzene (96) and CH2C12 (94, 302) solvates of the Cr(MorphoDtc)3 complex and of Cr(Et2Dtc)3 (542a) have been determined (Table XIV). 

FIGURE 7.22. Chemical structure of the benzene and napthalene side-walled water-soluble metallo-hosts and the X-ray structure of the ruthenium free precusor (front) revealing the U-shaped cavity . 

Ingold, C. K. The structure of the benzene nucleus. I. Intra-nuclear tautomerism. Trans, chem. Soc. [London] 1922, 1133. 

The problem of Aromaticity has always been one of the most difficult and fascinating problems in chemistry. It is usually stated in the literature that aromaticity has constituted a challenge to both the theoretican and the chemist since 1865, when August Kekule introduced his intuitive idea on the structure of the benzene molecule... 

Since each carbon atom is sp2 hybridized, a p orbital perpendicular to the plane of the ring remains on each carbon atom. These six p orbitals can be used to form v molecular orbitals, as shown in Fig. 14.50(a). The electrons in the resulting tt molecular orbitals are delocalized above and below the plane of the ring, as shown in Fig. 14.50(b). This gives six equivalent C—C bonds, as required by the known structure of the benzene molecule. The benzene structure is often written as... 

In order to make the ketone formula possible in accordance with the structure of the benzene ring it is necessary to consider the double bonds as changing or oscillating to the positions indicated in the above formula. When reduction to hydro-quinone occurs the double bonds oscillate back to their original position. 

FIGURE 21.9 Proposed lowest energy structures of the benzene dimer. d distance between planes, d lateral offset. 

Of interest also is the book by Wibaut entitled Chemistry in Wartime in the Netherlands (196) with sections on hydrocarbons, dissociation of aryl ethane derivatives, and structure of the benzene nucleus. 

Figure 1.7 X-ray costal structure of the benzene-hexafluorobenzene 1 1 complex, measured at 30 l< in the lowest-temperature modification [17bj.

A simpler way of drawing the structure of the benzene molecule and other compounds containing the benzene ring is to show only the skeleton and not the carbon and hydrogen atoms. By this convention the resonance structures are represented by... 

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