The examples (19, 20, 21 & 22) are cases of cis - benzyne type triple bond. The trans - triple is found as a transition state in the isotope scrambling of cis-hexa-3-ene-1,5-diyne-1,6-d2 (25) {ref.31}. The cyclic diallene is possible on our model .

The cis and trans triple bonds had been postulated as excited state by Ingold and King {ref.32}.

Aromaticity: The essential requirement for aromaticity is a cyclical exchange of electrons giving rise to a ring current noticeable in the nmr spectrum {ref.33}. On our model there are two extreme positions for the ring atoms. The first is the single bonded carbon ring shown in (3). The second extreme is the triple bonded benzyne mode shown in (26b). The composite of these two extremes would bring about a cyclical contact of all the ring carbon atoms with their adjacent neighbors leading to the equivalent of the ring current in a magnetic field. The bond distance would be the average (142pm) of the single (154pm) and the benzyne bond (131pm). The planarity of the substituent would also be the average of the two possible positions. The apex b-surfaces would only be transiently bonded and would be available for further complex formation. The benzene chromium complex (27) would be of this type.

Fig. 26a - Benzyne vibrational mode. R=Carbon atoms of benzene ring. Single bonded state as in photo3. Hydrogens below the plane of the ring. Carbons tetrahedral.

Fig. 26b - Benzyne mode. Hydrogen above the plane of the ring.

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Fig.27 Benzene-Chromium complex.

Fig.28 Aromatic cyclooctatetraene derivative.

The above view of aromaticity does not require any fixed number of electrons such as 4n+2 for aromatic stabilization. A cyclic planar system of alternating double bonds would serve for stabilization. The dibenzo cyclo octa tetraene (28) is a planar molecule {ref.34}, the cylcopropene system making it so. It is also stable. We believe it is aromatic but there is no way of proving it.

In a similar manner cyclopentadienyl anion and the tropylium cation could be aromatic.

Bare Atom Complexes: A number of octahedral, prismatic and anti prismatic complexes with a ‘bare’ carbon atom at their center had been prepared in the recent years. The nature of bonding in these complexes is not known. The octahedral and the anti prismatic can be envisaged on our model. But we defer a discussion of these to a future time.Implications of the model: The idea of a determinist model being seminal, the above treatment may be considered imperfect and incomplete. The purpose was to present a new insight into structural chemistry wherein the experimental data do not fit the quantum model. The possibility of chirality at the atomic level and of isotopic isomerism are dealt with in the accompanying paper on silicon {ref.35}.