Benzene complexes, hydrocarbon

Silver perchlorate forms solid complexes with aniline, pyridine, toluene, benzene and many other aromatic hydrocarbons [1], A sample of the benzene complex exploded violently on crushing in a mortar. The ethanol complex also exploded similarly, and unspecified perchlorates dissolved in organic solvents were observed to explode [2], Solutions of the perchlorate in benzene are said to be dangerously explosive [3], but this may be in error for the solid benzene complex. The energy released on decomposition of the benzene complex has been calculated as 3.4 kJ/g, some 75% of that for TNT [4],... 

Reaction X. (6) Catalytic Conversion o Simple Hydrocarbons into more Complex Hydrocarbons.—These reactions are usually accomplished at high temperatures in presence of catalysts. Acetylene, propylene and even methane can be converted into benzene. (E.P., 374,422 369,351 366,394.)... 

PNA (polynuclear aromatic) any of numerous complex hydrocarbon compounds consisting of three or more benzene rings in a compact molecular arrangement. Some types of PNA s are known to be carcinogenic (cancer causing). 

Aromatic Compounds. Forms solid complexes with aniline, pyridine, toluene, benzene, and many other aromatic hydrocarbons benzene complex explodes violently on crushing in a mortar.2... 

Benzene, as is well known, is easily converted at high temperatures into diphenyl and complex hydrocarbons. Lob7s1 method is very well suited for preparing diphenyl on a small scale. Metallic wires serve the same purpose as carbon filaments. Diphenylbenzene occurs as a by-product in small quantity. 

The prismatic cyclopentadienyl and benzene complexes of transition metals are reminiscent of the polycyclic hydrocarbon pris-manes. Figure 3-28 shows ferrocene, (C5H5)2Fe, for which both the barrier to rotation and the free energy difference between the prismatic (eclipsed) and antiprismatic (staggered) conformations are very small [75], Figure 3-28 also presents a prismatic model with Ay, symmetry for dibenzene chromium, (C6F[6)2Cr. 

Hexa-chlor benzene is formed by the chlorination not only of benzene itself, but also of other more complex hydrocarbons, e.g, naphthalene, anthracene, phenanthrene, di-phenyl methane (but not diphenyl). Penta-chlor benzene is of interest because it was at one time supposed to exist in isomeric forms which is contrary to the Kekule theory. 

Benzo-quinone.—Benzoquinone, or more commonly, simply quinone, is the most common and important of the quinones derived from benzene. Other important quinones will be met with when we study derivatives of the more complex hydrocarbons napthalene and anthracene. Benzoquinone is the one we have used as our example in the above discussion and it is the para-di-keto benzene. It was first obtained by the oxidation of quinic acid, which in turn was obtained from quinine, hence its name. It may also be prepared by oxidizing... 

Complexes. Silver tetrafluoroborate is insoluble in cyclohexane but very soluble in water, ether, toluene, and nitromethane, and moderately soluble in benzene and cyclohexene. - Solubility in the unsaturated hydrocarbons is attributed to n-bond formation between the unsaturated compound and silver ion. Complexes have been observed with both ir-electron donors and lone-pair donors thus Meerwein prepared stable complexes with benzene, mesitylene, cycloheptatriene, diethyl ether, dimethyl sulfoxide, and a series of acid nitriles. However, the silver tetrafluoroborate-benzene complex is reported variously as a 1 1 complex, a 1 2 complex, and as a 2 3 complex. ... 

For moderately weathered oils and refined products (for example, —15 to 30% weathered), significant losses occur in M-aUcanes and relatively low-molecular-weight isoprenoid compounds. Rapid loss of volatile aromatic compounds is clear. When oils are weathered to a certain degree (approximately in the range of 20 to 25% weathering for most oils), the BTEX and C3-benzenes could be completely lost, and the loss of Cq and Cl- naphthalenes can be significant. The ratio of GC-resolved peaks to UCM can be considerably decreased due to the preferential loss of resolved hydrocarbons over the unresolved complex hydrocarbons. The biomarker compounds are enriched. 

If the oil phase is not an alkane, but behaves similarly to an alkane, it is characterized by its equivalent alkane carbon number or EACN (136). It has been shown that on an ap-olarity scale, cyclohexane EACN is 3, alkylcyclohexane EACN is equal to its aUcyl group ACN plus 3, while benzene EACN is 0, and alkylbenzene EACN is equal to its aUcyl group ACN. As a matter of fact, the more polar the oil the lower its EACN. For instance the ethyl oleate EACN is about 6. Since it contains a chain, this means that the ester group accounts for a 12-unit reduction in the EACN. Complex hydrocarbon mixtiues can be assigned an EACN too, according to a simple mixing rule which is more or less followed (136,137). 

Fig. 17 Structures of benzene complexes with hydrocarbon molecules...

Dehydrogenation (the conversion of alicycllc or hydroaroraatic compounds into their aromatic counterparts by removal of hydrogen and also, in some cases, of other atoms or groups) finds wide appUcation in the determination of structure of natural products of complex hydroaroraatic structure. Dehydrogenation is employed also for the synthesis of polycyclic hydrocarbons and their derivatives from the readily accessible synthetic hydroaroraatic compounds. A very simple example is the formation of p-raethylnaphthalene from a-tetra-lone (which is itself prepared from benzene—see Section IV,143) ... 

The metal-ion complexmg properties of crown ethers are clearly evident m their effects on the solubility and reactivity of ionic compounds m nonpolar media Potassium fluoride (KF) is ionic and practically insoluble m benzene alone but dissolves m it when 18 crown 6 is present This happens because of the electron distribution of 18 crown 6 as shown m Figure 16 2a The electrostatic potential surface consists of essentially two regions an electron rich interior associated with the oxygens and a hydrocarbon like exterior associated with the CH2 groups When KF is added to a solution of 18 crown 6 m benzene potassium ion (K ) interacts with the oxygens of the crown ether to form a Lewis acid Lewis base complex As can be seen m the space filling model of this... 

Coke-oven tar is an extremely complex mixture, the main components of which are aromatic hydrocarbons ranging from the monocyclics benzene and alkylbenzenes to polycycHc compounds containing as many as twenty or more rings. HeterocycHc compounds containing oxygen, nitrogen, and sulfur, but usually only one heteroatom per ring system are present. Small amounts of paraffinic, olefinic, and partly saturated aromatic compounds also occur. 

The solvent is then evaporated, and the unconverted sterol is recovered by precipitation from an appropriate solvent, eg, alcohol. The recovered sterol is reused in subsequent irradiations. The solvent is then evaporated to yield vitamin D resin. The resin is a pale yeUow-to-amber oil that flows freely when hot and becomes a brittie glass when cold the activity of commercial resin is 20 30 x 10 lU/g. The resin is formulated without further purification for use in animal feeds. Vitamin D can be crystallized to give the USP product from a mixture of hydrocarbon solvent and ahphatic nitrile, eg, benzene and acetonitrile, or from methyl formate (100,101). Chemical complexation has also been used for purification. 

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