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High resolution infrared spectroscopy has permitted a determination of the configurations of the epimeric 1,5-dimethylbicyclo[3,3,l]non-2-en-9-ols. The occurrence of hydrogen bonding (OH+x) in one isomer has been related to gas-liquid chromatographic retention times of these compounds. The appearance of v(CH) and 6(CH,) absorptions at abnormally high frequencies can be correlated with the non-bonded intractions inherent in this ring system, and strongly indicate the unexpected twin-chair conformation for the bicyclo[3,3, llnonane framework.IN view of the semi-rigid nature of the bicyc!o[3,3,l]nonane ring system, an examination of the chemical and physical properties of a series of such compounds was of interest.l In the present work a detailed survey of the infrared spectra has revealed unusual absorptionsHydroxyl stretching absorptions in carbon tetrachloride.

synopsisMechanical and solution properties, melting transitions, torsional stiffness temperatures, Tf, and selected modulus-temperature curves are presented for copolymers of the N-n-alkylacrylamides with vinylidene chloride. Copolymers were prepared at 6OoC across the range of compositions, using &s comonomers N-n-butyl-, octyl-, dodecyl-and oleyl-acrylamide, which have amorphous side-chains, and N-n-octadecyl acrylamide and n-octadecyl acrylate whose side-chains are crystalline. The mechanical properties reflected the effect of the decline in backbone crystallinity and the simultaneous development of strong intermolecular interactions in the amorphous stage. Copolymers were stiff or showed brittle failure across the compositional range except when intermolecular forces were reduced (with n-octadecyl acrylate) and side-chain crystallization eliminated (with N-oleylacrylamide). These systems and the n-dodecylacrylamide copolymers had yield strengths less than brittle strengths and substantial elongations.Backbone crystallinity w&s eliminated a t about 15 mole % amide and side-chain crystallinity vanished at less than 10 mole yo of the amide in the N-n-octadecylacrylamide series. No depression in side-chain melting point occurred with dilution by segments of vinylidene chloride. Over-all decline in the flex-temperature was the normal monotonic function of composition except that values increased in magnitude at high vinylidene chloride contents, the effect presumably being caused by the presence of crystallinity.An empirical equation was developed which permitted the calculation of Tf for any N-n-alkylacrylamide composition with any number of carbon atoms in the side-chain, above 3.

Aliphatic Peracids in Solution and Solid State 5537 yielded a 2,4-dinitrophenylhydrazone, m.p. 122.5-123°, undepressed by admixture with an authentic sample.29 The 2,4-dinitrophenylhydrazone of isovaleraldehyde, m.p. 125.5-126°, strongly depressed the melting point of the above sample.Neopentyl Iodide with Bromine.-Neopentyl iodide (92.0 mmoles) reacted with bromine (93.3 mmoles) in petroleum ether for 1.25 hours at -78°and 1.5 hours at 0°g ave a very small amount (0.57 g., 4%) of an impure low boiling fraction, «22d 1.4448, b.p. 55-58°( 120 mm.), micro b.p. 106°; re-ported30 for ¿-amyl bromide, b.p. 108°(765 mm.), «20d 1.4421. There was not enough to refractionate.Analysis was obtained on a similar material, probably tamyl bromide, from an earlier run, b.p. 50.5-52°( 115 mm.), «25d 1.4370.

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