Hydroquinone C6h4oh2

^vDQQCD^

Here we have two Hydroxyl groups attached to the Benzene ring. They are attached at the top and bottom. The whole is really an octahedron, as in Benzene, but slightly elongated. The two Oxygens seem to elongate the molecule a little but the whole is stable.

COMPOUNDS

BENZALDEHYDE C.H3CHO

fig. 207. benzaldehyde c,h»cho

This is a ring compound derived from Benzene. It has an aldehyde group (CHO) attached to one corner. It is described as the usual hexagonal ring with a wart at one corner.

This corner is composed as follows. Usually the six funnels of the corner Carbon (two funnels of which are used in the dodecahedron) point outward with the six small H3 groups floating over them. In this case there is no corner Carbon but the six funnels and the Hydrogen atom form part of a complex body. The centre-piece of this body is the Oxygen. The eight funnels from the Carbon of the CHO divide into two groups of four and lie flat at each end of the Oxygen. The four central Carbon Anu circle round the Oxygen.

Above the four flat Carbon funnels there are three more Carbon funnels pointing outward. These are from the original six. Three of these six are shown at each end of the wart, sticking out but one at each angle of a triangle. The six balls of H3 do not float over the six funnels as before but are pulled down in some way and are not so definitely attached to their funnels. They are described as restless and dodging in and out. They are shown between these three funnels.

SALICYLIC ACID C6H4COOH.OH

FIG. 208. SALICYLIC ACID

SALICYLIC ACID C,HtCOOH.OH

Two varieties of this compound have been observed. Fig. 208.

In Type A the COOH and OH groups coalesce. Salicylic acid is fundamentally a Benzene ring. In type A we have an arrangement very much resembling Benzaldehyde. The five Carbon atoms in the ring are as in Benzaldehyde but the ' wart' has become larger as three Oxygen atoms are attached to the sixth Carbon, or rather take the place of the sixth Carbon. The three Oxygen atoms are side by side, with the four Anu from the Carbon circling round the central one. At the ends of the Oxygen atoms appear the four flat funnels from the Carbon atom of the Carboxyl group, while six funnels of the Carbon atoms belonging to the ring radiate out as in Benzaldehyde. In between these funnels, not still, but moving in and out, are the six balls from the Hydrogen of the COOH.

Type B. In this arrangement the OH group remiins at one corner as in Phenol, while the COOH group forms a " wart" on the sixth corner as in Type A except that there are only two Oxygen atoms instead of three.

There appeared to be a mixture of these two types within the specimen examined.

PYRIDINE C5HsN

FIG. 209. PYRIDINE C»H»N

PYRIDINE C,H,N

There are only five Carbon atoms in this compound, so the Nitrogen atom enters the ring and plays the part of the sixth Carbon. As there are only five Carbons, which provide ten funnels and not twelve, the dodecahedron in the centre would be incomplete. However, two groups from the Nitrogen, the two N24 groups, are given away by the Nitrogen and take the places of the two missing funnels. This produces an awkward-looking, asymmetric centre, somewhat dented in. Also there are only five Anu from the five Carbon atoms to provide the grand centre of the dodecahedron. Fig. 209.

The remainder of the Nitrogen atom takes the place of the sixth Carbon atom. The arrangement is stable and the whole is a very sluggish creature. The pear-shaped Nitrogen balloon N110 is in its usual place with the * dish * N63 below it. It is not possible to say how the valencies work The two N20 groups remain in their usual places.

NAPHTHALENE C..H.

The chemical formula for Naphthalene is C,,H,. Chemists have long postulated that the arrangement of the atoms of Carbon and Hydrogen in it can be represented in a flat space diagram only in some such form as follows:

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