eventuelle Reaktion nach Gl. (7) gemacht werden. Eine Abstraktionsreaktion erscheint jedoch aus folgenden Gründen weniger wahrscheinlich als eine Elektronenübertragung: Das CH,OH-Radikal reagiert mit CC14 wesentlich langsamer als das (CH3)oCOH-Radikal, wie es für e 9 -Übertragungs-reaktionen charakteristisch ist, während eine Abstraktion etwa gleich schnell verlaufen sollte. Außer-dem besitzen die Alkohol-und Ätherradikale eine stabilisierende 3-Elektronenbindung, und es erscheint fraglich, ob eine Reaktion nach Gl. (7) aus energetischen Gründen so schnell wie beobachtet ablaufen kann. Reaktionen des CClyRadikalsAbgesehen von den Kettenreaktionen in Lösun-gen von CCI4 und zso-Propanol bzw. Äthern führt keine andere Reaktion des CCl3-Radikals zu weiteren Cl e -Ionen. Es wurde jedoch beobachtet, daß in Gegenwart von Sauerstoff in den p'-bestrahlten Lö-sungen Reaktionen ablaufen, die zu höheren Ausbeuten an HCl führen. Da dieser Effekt schon durch äußerst geringe Mengen an 02 10 _5 M) hervorgerufen wird, liegt möglicherweise eine katalytische Wirkung vor. Eine eingehende Analyse würde jedoch über den Rahmen dieser Arbeit hinausgehen. Die Reaktionen chlorierter Äthylene mit hydratisierten Elektronen und OH-Radikalen in wäßriger LösungThe The reactions of chlorinated ethylenes with hydrated electrons and OH radicals have been investigated by using the method of pulse radiolysis. In addition y-ray experiments were carried out. The reduction of the solutes occurs via a dissoziation electron capture process. The rate constant for the reaction of e® with the more chlorinated compounds is essentially diffusion controlled (k= (1-2xl0 10 1-mole -1 sec -1 ). Vinylchloride and 1,2-irans-dichloroethylene react more slowly. This can be related to the higher stability of the C -Cl bond in these compounds.Hydroxyl radicals add to the C = C double bond of the chlorinated ethylenes. The rate constant for the reaction with vinylchloride was determined to 7.1 x 10 9 1-mole -1 sec -1 , and decreases with increasing degree of chlorination of the ethylenes. This effect is explained by the decreasing electron density on the C-atoms and steric hinderance. The hydroxyl radical always adds to the C-atom carrying the smallest number of Cl-atoms. In its reaction with 1,2-dichloro-, trichloro-and tetrachloroethylene a radical is produced with an OH group and a Cl-atom on the same C-atom. It eliminates HCl to form a C = 0 bond with &>7 x 10 5 sec -The >C -C = 0 type radical produced in this reaction has an optical absorption in the near UV (f2G5 nm^Cl -3)xl0 3 1-mole -1 cm -1 ).The OH radical addition products of vinylchloride and 1,1-dichloroethylene do not eliminate HCl and have no absorption in the visible and near UV.Halogenhaltige organische Verbindungen sind Substanzen, die im allgemeinen sehr reaktiv gegenüber Elektronen sind. In einer Reihe von Untersuchungen ihrer wäßrigen Lösungen wurden die

Following a discussion of bonding, the structures of the known carboranes of the clovo type and of the incompletely condensed types are described; the recently discovered carboranes with high carbon contents, such as tetracarbahexaborane ("boracarbane") are also discussed. The preparation of carboranes from polyboranes and the possibility of obtaining organ0 carboranes from organoboranes are then described. Some rearrangements which take place within the carborane skeleton are also mentioned.Chem. 2, 1115 (1963). I921 L. I. Zakharkin, V. I. Stanko, V. A . Brattsev, Yu. A. Chapovskii, A . I. Klimova, 0. Yu. Okhlobystin, and A . A . Ponomarenko, Doklady Akad. Nauk SSSR 155, 1119 (1964); Chem. Abstr. 61, 3131c (1964). Angew. CIiem. ititernat. Edit. I VoI. 6 (1967) 1 No. 3

J-Methyl-5-norbornen-2-one (X) had the following spectral data: ir, carbonyl att 1745 cm-1; nmr, vinyl hydrogens at 8 6.1 and 6.5 (m, 2.0 hydrogen), methyl group at 8 1.1 (d, 2.8 hydrogens), all other hydrogens from 6 1.4 to 3.0 (m, 5.3 hydro-Reaction of Mixtures of Norcamphor and 5-Norbornene-2-one with Sodium Hydride and Methyl Iodide.-The following reactions were run with 0.31 g (0.0076 mol) of a sodium hydride dispersion: a mixture of 1.65 g (0.015 mol) each of norcamphor and 5-norbornene-%one with 2.1 g (0.015 mol) of methyl iodide; a mixture of 1.65 g (0.015 mol) of 5-norbornene-2-one and 6.6 g (O.Os0 mol) of norcamphor with 10.5 g (0.07 mol) of methyl iodide; and a mixture of 1.65 g (0.015 mol) of 5-norbornene-2-one and 0.83 g (0.0075 mol) of norcamphor with 2.1 g (0.015 mol) of methyl iodide. The main products were 2-methoxy-5-norbornene (VI11 ) , 2-methoxy norbor nene (I1 ) , and 3-me t hylnor camphor (IV). The ratio of products indicated that both ketones reacted with sodium hydride at the same rate. The reason that no 3methyl-5-norbornen-2-one (X) was formed is probably due to rapid proton transfer from norcamphor to the enolate of 5norbornen-2-one. This transfer, much faster than methylation with methyl iodide, would give a product derived from the more stable enolate of norcamphor.Preparation of 2-Methoxy-2-norbornene (XI).-2-Methoxy-2norbornene (XI) was prepared in two steps by a procedure similar to that of Johannissian and Akunian.lsIn a 50-ml flask under nitrogen was placed 4.4 g (0.09 mol) of norcamphor, 16 ml of methanol, a little p-toluenesulfonic acid, and 13 ml of trimethyl orthoformate. After refluxing 1 hr, the solution was cooled, a little potassium t-butoxide was added to neutralize the acid, and the solvent was boiled off. The product was distilled a t 76-77" (20 mm); the yield of 2 2dimethoxynorbornane was 5.5 g (88%).A mixture of 5.3 g of this material and a little p-toluenesulfonic acid in a distillation apparatus was heated in an oil bath around 220'. The solution boiled vigorously and material slowly distilled over under nitrogen. The distillate was redistilled through a Nester/Faust Teflon spinning-band annular still, and the enol ether collected at 77-79" (75 mm). The yield of 2-methoxy-2norbornene was 0.90 g: ir showed a strong C=C band at 1610 cm-1; nmr, vinyl hydrogens at 6 4.62 (d, 0.8 hydrogen), methoxy hydrogens at 8 3.52 (9, 3.1 hydrogens), bridgehead hydrogens at 8 2.75 and 2.90 (b, 1.7 hydrogens), all other hydrogens at 8 gens ). (13) A. Johannissian and E . Akunian, Bull. Univ. h a t RSS Armenie, I , 235, 245 (1930); Chem. Abslr., 26, 921 (1931).1.0-2.0 (m, 6.0 hydrogens). The material was very sensitive to moisture and could be stored only under a dry atmosphere.Reaction of 2-Methoxy-2-norbornene (XI) with Sodium Hydride and Methyl Iodide.-2-Methoxy-2-norbornene (100 pl) was treated with 0.30 g (0.0074 mol) of a sodium hydride dispersion and 2.0 g (0.014 mol) of methyl iodide in 25 ml of glyme. Analyses of the reaction mixture after work-up showed the chief product ...

The reduction of carbon tetrachloride by hydrated electrons, H atoms and reducing radicals has been investigated by pulse radiolysis conductivity methods. It has been found that one Cl® ion is formed per reducing species. A chain reaction is observed in the γ-radiolysis of solutions of CCl4 and iso-propanol, diethylether, and tetrahydrofurane. Mechanisms and kinetic data are discussed.

Whereas free BN radicals with unresolved ESR signals are formed on dehalogenation of pyridine-and 2-alkylpyridinedialkylchloroboranes by lithium in tetrahydrofuran 111 at 0 to 5"C, associated radicals ( I ) , whose ESR spectra show a hyperfine structure of ten lines (distances: 3.83 gauss), are obtained from the adducts of dialkylchloroboranes and 4-alkylpyridines. The resolution can be ascribed to the coupling of the free electron to three boron atoms121. In the spectrum of ( I ) in 10-2 M solution, an additional hyperfine structure (see Fig. 1) also appears, the resolution of which varies with the linewidth associated with the substituent R in the aromatic ring, in the order CH2C6Hs M CH3 w CzHs > C3H7 > CH(CH3)z > C(CH3)3. Simultaneously the association (measured cryoscopically in benzene) decreases from x w 3 to x w 1.5. Fig. 1. ESR spectrum of the 4-methylpyridine-diethylboryl radical; ca. 0.001 M in diethyl ether. -The 4-methylquinoline-diethylboryl radical (2) is monomeric in benzene. In agreement with this fact the hyperfine structure of the ESR spectrum shows a clear (1 : 1 ) splitting (14 gauss), which can be ascribed to the coupling of the free electron with one proton. ( I ) and (2) are highly colored, very viscous liquids, which are decolored by air.Dehalogenation of 3-alkylpyridine-dialkylchloroboranes,even at 0 "C, gives either no (3,5-lutidine, 3,4,5-trimethylpyridine) or only a very unstable free radical (3-methylpyridine). From 3,5-lutidine-chlorodiethylborane one obtains a dark red, diamagnetic liquid (b.p. 48 "C/lO-3 mm) which is composed mostly of N-diethylboryl-l,4-dihydro-3,5-dimethylpyridine (3) and yellow crystalline N,N'-bis(diethylboryl-l,1'-2,2'tetrahydro-3,3',5,5'-tetramethy1-A2Jf-bipyridine (4), m.p. 93 " C ; 85 % yield). Structures (3) and (4) were proved by 1H-NMR. 4 "'"yg CH3 -+ 4 Li(THF) -4 LiCl I I H5C2-BC1 CZH5If pyridine-chlorodiethylborane is dehalogenated in boiling tetrahydrofuran no free radical is formed, but instead a disproportionation product (b.p. 88-89 "C/14,mm) analogous to (3) ; the dehydrogenated portion corresponding to (4) is a dark solid. . 76, 649 (1964); Angew. Chem. internat. Edit. 3, 514 (1964).[2] Coupling of the spin of the unpaired electron with three symmetrical equivalent 11B-nuclei ( I = 3/2) leads to 2(3x3/2)+ 1 = 10 hyperfine structure lines.Thiepins contain a cyclic 8x-electron system, so that, as with oxepins, rearrangements to more stable ring systems are to be expected. Indeed, when 3, 5-diacetoxy-4-phenylbenzo[blthiepin ( I )is heated under reflux with sodium acetate in acetic anhydride for 6 hours, 1,3-diacetoxy-4-acetylthio-2phenylnaphthalene (Z), m.p. 175-176 OC (from methanol), is formed in 53 % yield. The rearrangement is thus analogous to that observed with benzo[b]oxepin derivatives 121. The structure (2) is proved by elemental analysis, the IR spectrum [in KBr; vc=o = 1764 cm-1 (aromatic acetate), vc=o = 1710 cm-1 (aromatic thioacetate)], the NMR spectrum [in CDC13; T = 8.15 and 8.03 (each 3 H of the two acetate groups), T = 7.65 (3 H o...