Detail of "7098-22-8"

Reference

Infrared Active Methyl Group Vibrations in Tetratetracontane: A Probe for Chain End Organization and Crystal Structure

Infrared Active Methyl Group Vibrations in Tetratetracontane: A Probe for Chain End Organization and Crystal Structure. Gorce, Jean-Philippe; Spells, Stephen. J.; Zeng, Xiang-Bing; Ungar, Goran (Materials Research Institute, Sheffield Hallam University, Sheffield S1 1WB, UK). Journal of Physical Chemistry B, 108(10), 3130-3139 (English) 2004 American Chemical Society. CODEN: JPCBFK. ISSN: 1520-6106. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) Section cross-reference(s): 73, 75 By crystg. tetratetracontane (n-C44H90) from soln. in toluene under a variety of conditions, the orthorhombic I and (011) tilted monoclinic forms were identified by X-ray diffraction (XRD) and the orthorhombic II form was inferred from IR spectroscopy. Application of pressure to the crystal mat resulted in a proportion of triclinic structure. At 75 °C, the (011) monoclinic form transforms to a (101) tilted monoclinic phase. Differing extents of chain end and translational disorder are believed to be responsible for these different crystal forms, which were studied using the conformational sensitivity of several IR-active Me and methylene group vibrations. Depending on the crystal phase, the sym. Me deformation around 1378 cm-1 shows differing characteristics, and both the rocking and the asym. C-H stretching vibrations show different components. An increase in the end-gauche methylene wagging absorbance in the (101) monoclinic structure with increasing temp. together with the presence of even order bands from the CH2 methylene rocking-twisting progression are also attributed to chain end disorder. The implications of the results on the Me sym. deformation for the use of the methylene wagging region of the spectrum to characterize disorder in alkyl chains are discussed.

Solubilities of carbon dioxide in heavy normal paraffins (C20-C44) at pressures to 9

Solubilities of carbon dioxide in heavy normal paraffins (C20-C44) at pressures to 9.6 MPa and temperatures from 323 to 423 K. Gasem, Khaled A. M.; Robinson, Robert L., Jr. (Sch. Chem. Eng., Oklahoma State Univ., Stillwater, OK 74078, USA). J. Chem. Eng. Data, 30(1), 53-6 (English) 1985. CODEN: JCEAAX. ISSN: 0021-9568. DOCUMENT TYPE: Journal CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Section cross-reference(s): 68 Soly. data were obtained for CO2 in n-eicosane [112-95-8], n-octacosane [630-02-4], n-hexatriacontane [630-06-8], and tetratetracontane [7098-22-8] at 323-423 K and pressures up to 9.6 MPa. At CO2 mole fractions <0.45, the soly. data are described by the Krichevsky-Kasarnovsky equation with av. deviations of 0.002 mol fraction units.