Carbon Deuterium Research Articles

The study of the alloys of platinum and tin by chemisorption

Studies of the adsorption of carbon monoxide, ethene, and deuterium on platinum, Pt 3Sn, PtSn, and PtSn 2 have identified significant differences between the surface and the bulk composition of the alloys, in agreement with current theories. After annealing in vacuo, the surfaces are considerably enriched in tin, this enrichment occurring mainly at the expense of the subsurface zone, which thus becomes correspondingly enriched in platinum. Carbon monoxide adsorption induces a reversible surface enrichment in platinum. Temperature-programmed desorption experiments reveal that as the proportion of tin in the alloys increases, desorption of the above-mentioned gases becomes progressively easier. This suggests a loosening of the chemisorptive bond caused by the adsorbing platinum atoms becoming surrounded by tin atoms (the “ligand effect”). Adsorption of ethene on platinum leads to extensive auto-hydrogenation of the ethene and to carbon formation; Pt 3Sn and PtSn, however, adsorb ethene reversibly.

Pressure broadening of the J = 1 ← 0 transition of carbon monoxide

The pressure broadening of the carbon monoxide line near 115 GHz was measured at liquid nitrogen, dry ice, and room temperature, with typical experimental uncertainties of about 10%. Broadening gases were carbon monoxide, hydrogen, deuterium, helium, neon, and argon. No significant lineshifts were observed.

The proton magnetic resonance spectra of pyridine 1-oxides and their conjugate acids

The p.m.r. spectra of eleven pyridine 1-oxides have been measured in carbon tetrachloride, deuterium oxide, and 18N-deuteriosulphuric acid solution (corresponding to the neutral, hydrogen-bonded, and O-protonated species). The average downfield shifts for the α, β-, and γ-proton lines have been calculated and the results are discussed. Electron distributions and coupling constants are compared with those of the corresponding pyridines and pyridinium salts.

THE REACTION OF UNSATURATED CARBOHYDRATES WITH CARBON MONOXIDE AND HYDROGEN: V. ABSOLUTE STEREOCHEMISTRY OF ANHYDRODEOXYHEPTITOLS FROM 3,4,6-TRI-O-ACETYL-D-GLUCAL. STEREOCHEMISTRY OF HYDROFORMYLATION. CONFORMATIONAL ANALYSIS

3,4,6-Tri-O-acetyl-D-glucal reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield a mixture of two epimeric anhydrodeoxyheptitols, namely, 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-manno-heptitol (I) and 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-gluco-heptitol (II). De-O-acetylation of the mixture, followed by chromatographic separation, yielded crystalline 2,6-anhydro-3-deoxy-D-manno-heptitol (III) and 2,6-anhydro-3-deoxy-D-gluco-heptitol (IV). Reaction of the mixture of heptitols (I) and (II) with p-bromobenzenesulfonyl chloride, followed by fractional crystallization of the brosylates, gave pure 4,5,7-tri-O-acetyl-2,6-anhydro-1-O-(p-bromophenylsulfonyl)-3-deoxy-D-gluco-heptitol (VII). The absolute configuration of (VII) has been previously established by X-ray crystallographic analysis. The absolute configuration of (III) was established by correlation with that of (VII). The conversion of compound (II) into various derivatives is described.Reaction of 3,4,6-tri-O-acetyl-D-glucal with carbon monoxide and deuterium afforded 2,6-anhydro-3-deoxy-D-manno-heptitol-1,1,3-2H3 (XIII) and 2,6-anhydro-3-deoxy-D-gluco-heptitol-1,1,3-2H3 (XIV). Examination of the nuclear magnetic resonance (n.m.r.) spectra of the normal and deuterated anhydrodeoxyheptitols confirmed the structural assignments and showed that cis addition to the double bond took place to give (XIV).Comparison of the exchange reaction of sodium iodide with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-gluco-heptitol (VIII) and with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-manno-heptitol (XV) revealed that the equatorial primary tosyloxy group of (VIII) was exchanged by iodine twice as readily as the axial primary tosyloxy group of (XV).

THE REACTION OF UNSATURATED CARBOHYDRATES WITH CARBON MONOXIDE AND HYDROGEN: II. STRUCTURE AND STEREOCHEMISTRY OF THE ANHYDRODEOXYHEXITOLS FROM 3,4-DI-O-ACETYL-D-XYLAL

3,4-Di-O-acetyl-D-xylal reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield 1,5-anhydro-4-deoxy-D-arabino-hexitol (I) and 1,5-anhydro-4-deoxy-L-xylo-hexitol (II). The stereochemistry at C-5 of the hexitols was elucidated by correlation with the triol ether (VI) obtained by sodium borohydride reduction of the periodate oxidation product of 1,4-anhydro-5-deoxy-D-arabino-hexitol (VII). Reaction of 3,4-di-O-acetyl-D-xylal with carbon monoxide and deuterium afforded 1,5-anhydro-4-deoxy-D-arabino-hexitol-4,6,6-H32 (VIII) and 1,5-anhydro-4-deoxy-L-xylo-hexitol-4,6,6-H32 (IX). Examination of the nuclear magnetic resonance (n.m.r.) spectra of the normal and deuterated anhydrodeoxyhexitols confirmed the structural assignments and showed that cis-addition to the double bond takes place to give (IX).

Pressure broadening studies on vibration-rotation bands, IV. Optical collision diameters for foreign-gas broadening of CO and DCl bands

Results are given for the pressure broadening of lines in the vibration-rotation bands of carbon monoxide and deuterium chloride, by a wide variety of added gases including both non-polar and polar molecules. Optical collision diameters have been calculated and considered in relation to the interaction forces likely to be involved. For carbon monoxide, a rough correlation is found between the optical collision diameter and the interaction potential for non-polar broadeners where dispersion forces are dominant, but derivations occur with some polar broadeners. Similar data for deuterium chloride illustrate the importance of dipolar forces, but no simple theory explains the results satisfactorily. The variation of line width with J quantum number is discussed.

Infrared spectra of crystalline and stereoregular polymers. II. Carbon—hydrogen and carbon—deuterium stretching frequencies of polypropylene and deuterated polypropylenes

AbstractThe polarized infrared spectra of polypropylene, poly(propylene‐1,1‐d2), poly(propylene‐2‐d), and poly(propylene‐3,3,3‐d3) in the carbon—hydrogen and carbon—deuterium stretching regions were observed and interpreted. The A and E components of each stretching mode were found to be at the same frequency. The polarization of both CH2 and CD2 symmetric stretching bands was observed to be weakly parallel. This observation would probably imply that the bisector of the HCH or DCD angle makes an angle somewhat less than 54° 44′ with the helical axis. The tertiary CH stretching frequency was found at about 2920 cm.—1. The two antisymmetric CH3 (or CD3) stretching frequencies were resolved in the polarized spectra of the polymers. From this infrared study, it is suspected that poly(propylene‐3,3,3‐d3) may have a different structure than the other polypropylenes used in this work.