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C6H5 STYROLENE

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Originally appearing in Volume V25, Page 1060 of the 1911 Encyclopedia Britannica.
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C6H5 STYROLENE.CH:CH2, also known as phenylethylene or vinylbenzene, an aromatic hydrocarbon found to the extent of I to 4% in storax; it also occurs with crude xylene in coal tar fractions. It may be obtained from storax by distillation with water, and synthetically by heating cinnamic acid with lime, by the action of aluminium chloride on a mixture of vinyl bromide and benzene, by removing the elements of hydrobromic acid from bromethylbenzene by means of alcoholic potash, or, best, by treating f9-bromhydrocinnamic acid with soda, when it yields styrolene, carbon dioxide and hydrobromic acid. It also results on condensing acetylene, and on reducing phenylacetylene by zinc dust and acetic acid. It is a clear, strongly refractive liquid, which has a pleasant odour; it boils at 144° and has a specific gravity of 0.925 at ()a. Styrolene is oxidized by nitric or chromic acids to benzoic acid; reduction gives ethylbenzene; hydrochloric and hydrobromic acids yield a-haloid ethylbenzenes, e.g. C6H5•CHC1'CH3; whilst chlorine and bromine give a$-dihaloid ethylbenzenes,, e.g. C6H5•CHC1-CH2CI. Tauern with the Hochgolling (9390 ft.), the Wolzer Alps with the Predigtstuhl (8349 ft.), the Rottenmanner Tauern with the Grosser Bosenstein (8032 ft.), and the Seckauer Alps or Zinken group, which culminates in the Zinkenkogel (7865 ft.). The principal ramifications of the primitive Alps of Carinthia and Styria are: the Stang Alps with the Konigsstuhl (7646 ft.) and Eisenhut (8007 ft.), the Judenburger or Seethaler Alps with the Zirbitzkogel (7862 ft.), and the Koralpen which culminates in the Grosser Speikkogel (7023 ft.). The Styrian Nieder Alps cover the country north and east of the Mur, and contain the Fischbacher Alps with the Hochlantsch (5646 ft.), the Wechsel group (5700 ft.), and the small Semmering group with the Stuhleck or Spitaler Alpe (5847 ft.), and the Sonnenwendstein (4994 ft.). In this group is the famous Semmering Pass, which leads from Lower Austria into Styria and is crossed by the Semmering railway. This railway, which was completed in 1854, is the oldest of the great continental mountain railways, and is remarkable for its numerous and long tunnels, its viaducts and galleries. It has a length of 35 m., beginning at Gloggnitz in Lower Austria and ending at Miirzzuschlag in Styria, and passes through some exceedingly beautiful scenery. The whole region is now a favourite summer resort. South of the Drave Styria is traversed by the following ramifications of the southern zone of the eastern Alps: the Bacher Gebirge with the Cerni Vrch or Schwarzer Berg (5078 ft.), and the Sannthaler or Steiner Alps with the Oistriza (7709 ft.) and the highest peak of the group, the Grintovc or Grintouz (8429 ft.), which is situated on the threefold boundary of Carinthia, Carniola and Styria. Here is also the mountain country of Cilli, with the highest peak, the Wachberg (3364 ft.). The mountains decrease in height from west to east, and the south-east of Styria may be described as hilly rather than mountainous. This part is occupied by the eastern outliers of the Alps, known as the Styrian hill country, and by the Windisch Buheln, which is one of the most renowned vine districts in the whole of Austria. Styria belongs to the watershed of the Danube and its principal rivers are: the Enns with its affluent the Salza, the Raab with the Feistritz, the Mur with the Murz, the Drau or Drave, and the Sau or Save, which receives the Sann and the Sotla. Styria has numerous small Alpine lakes of which the most important are the Grundel-see, the Toplitz-see, and the Leopoldsteiner-see. There is a mean annual difference of about 9° F. between the north-west and the south-east. The best known mineral springs are the alkaline springs of Rohitsch and Gleichenberg, the brine springs of Aussee, and the thermal springs of Tuffer, Neuhaus and Tobelbad. In spite of the irregular nature of the surface, but little of the soil can be called unproductive. Of its total area 47—49% is covered with fine forests. About 19% is arable land, 12% pastures, 5.6o% meadows, while 1•o6% is occupied by gardens and 1.4% by vineyards which produce wine of a good quality. Cattle-rearing has taken a great development and also dairy-farming in the Alpine fashion. A good race of horses is bred in the valley of the Enns, while poultry-rearing and bee-keeping are carried on in the south. Fish and game are also plentiful. The great wealth of Styria, however, lies underground. Its extensive iron mines, mostly at Erzberg, which were worked during the Roman period, yield nearly half of the total production of iron in Austria. The principal foundries are at Eisenerz, Vordernberg, Trofaiach, Hieflau, Zeltweg and Neuberg. Next in importance comes the mining of brown coal, which has also been carried on for a long time. The richest coalfields are situated near Leoben, near Voitsberg and Koflach, near Eibiswald and Wies, and round Trifail, Tuffer and Hrastnig. Its other mineral resources include graphite, copper, zinc, lead, salt, alum, potter's clay, marble and good mill and building stones. Iron-foundries, machine-shops and manufactures of various kinds of iron and steel goods are very numerous. A special Styrolene gives origin to three series of derivatives, two of which contain the substituents in the side chain, e.g. C6H6•CCI:CH1 or a-compounds, and C6H6•CH:CHCI, or w-compounds, whilst in the third the benzene nucleus is substituted. The a-halogen compounds are obtained by heating styrolene chloride (or bromide) with lime or alcoholic potash; they are liquids which have a penetrating odour, and yield acetophenone when heated with water to 180°. The w-chlor compound results when 14-phenyl-a-chlorlactic acid (from hypochiorous acid and cinnamic acid) is heated with water; it has a hyacinthine odour and yields phenylacetaldehyde when heated with water. Nitrostyrolene results when styrolene is treated with fuming nitric acid. Related to styrolene is phenylacetylene, C6H5.CCH, which results when a-bromstyrolene or acetophenone chloride are heated to 130° with alcoholic potash, or phenylpropiolic acid with water to 120°. It is a liquid, boiling at 139° and having a pleasant odour. It resembles acetylene in yielding metallic derivatives with ammoniacal copper and silver solutions. On solution in sulphuric acid, followed by dilution with water, it yields acetophenone. Stilbene or toluylene, C6H6'CH : CH•CsH5, is symmetrical diphenylethylene. It may be obtained by distilling benzyl sulphide or disulphide, by the action of sodium on benzaldehyde or benzal chloride, by distilling fumaric and cinnamic phenyl esters: C6H5O.00•CH:CH•CO.006H6–3CO2+C6H6•CH:CH•CO-OC6H5– 2CO2 +C6H6•CH : CH•C6H6 (Ber.,18, p.1945), and fromchlorasymmetrical diphenylethane derivatives which undergo a rearrangement when heated (Ber., 7. p. 1409). Stilbene (from Gr. vrt su^, to glisten) crystallizes in large, colourless, glistening monoclinic plates, which melt at 124° and boil at 306°. On passing the vapour through red-hot tubes it yields anthracene and toluene. Reduction with hydriodic acid gives dibenzyl, and heating with sulphur gives tetraphenylthiophene or thionessal. Many derivatives are known, some of which exist in two structural forms, exhibiting geometrical isomerism after the mode of fumaric and maleic acids. Those substituted in the benzene nucleus are obtained by condensing two molecules of a substituted benzyl and benzal chlorides. The diortho and dipara dinitro compounds result from the action of alcoholic potash on ortho- and para-nitrobenzyl chlorides. The latter on reduction yields a diamino compound, the disuiphonic acid of which on diazotization and coupling with a phenol, &c., gives valuable substantive cotton dyes after the type yielded by Benzidine. Stilbene bromide when treated with alcoholic potash gives diphenyl acetylene or tolane, C6H5.0 C C6H6.
End of Article: C6H5 STYROLENE
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