X-ray diffraction study of the structure of 1-propanol at –25°C

Abstract

Then the coupling tensors for the internal modes of the molecule have to be calculated from a complete forceconstant matrix. We do not see a solution in which the quantum-chemically calculated static densities can correctly be converted to dynamic densities.References COPPENS, P. (1969). Acta Cryst. A25, 180-186. FRITCHIE, C. J. (1966). Acta Cryst. 20, 27-38. HASE, H. L., REITZ, H. & SCHWEIG, A. (1976). Chem. Phys. Lett. 39, 157-159. HIRSHFELD, F. L. (1976). Acta Cryst. A32, 239-244. PAWLEY, G. S. (1971). Acta Cryst. A27, 80-81. REES, B. (1976). Acta Cryst. A32, 483-488. SCHERtNGER, C. (1972a). Acta Cryst. A28, 616-619. SCHERINGER, C. (1972b). Acta Cryst. A28, 516-522. SCHERINGER, C. (1973). Acta Cryst. A29, 554-570. SCHERINGER, C. (1977a Molybdenum Ke X-radiation, monochromated by an NaC1 single crystal, was scattered in 1-propanol at -25°C. The angular distribution of the scattered X-ray intensity was determined and used for the calculation of the experimental pair function. On the basis of some models of the structure of liquid 1-propanol, the theoretical curves of pair functions were calculated and then compared to the experimental curve. The most probable model of the liquid is that of statistically distributed chains of 1-propanol molecules.

The Molecular Conformations and Intermolecular Correlations in Positional Isomers 1- and 2- Propanols in Liquid State Through Neutron Diffraction

“…In 2-propanol, data shows a strong pre-peak at a scattering vector q0.7Å -1 similar to one obtained in earlier Howells et al TOF, neutron data (Zetterström et al, 1991(Zetterström et al, , 1994 and also in recent x-ray data (Takamuku et al, 2002). For 1-propanol, however, there is no significant pre-peak at a scattering vector q ~0.7 Å -1 similar to earlier x-ray data (Mikusinska-Planner, 1977) though in recent x-ray data there is a weak pre-peak at q ~0.7 Å -1 . The cross-section data can be separated into "self" and "interference" terms,…”

“…Alternatively, a careful analysis via geometrical modeling can also yield satisfactory results in several cases with relatively large molecules (Magini et al, 1982;Sarkar & Joarder, 1993. Similar efforts have been also made with x-ray data earlier for liquid t-butanol and 1-propanol (Karmakar et al, 1995;Mikusinska-Planner, 1977) and in recent past for liquid 1-and 2-propanols in aqueous solutions (Takamuku et al, 2002. In view of large conformational differences in liquid 1-and 2-propanols the investigation of their average molecular associations in liquid state is a quite interesting.…”

“…It is however to be noted here that the average molecular association extracted here is very different from the probable chain molecular association suggested in Takamuku Since 1-propanol in liquid state at RT has significantly different molecular conformation and properties, its molecular association in liquid state would be interesting. Further, the only neutron data available does not show any significant pre-peak like one for the earlier x-ray diffraction data (Mikusinska-Planner, 1977). The recent x-ray data however shows a weak pre-peak at q~ 0.7-0.8Ǻ -1 but less prominent than one in 2-propanol data.…”

“…The structures in gaseous phases were obtained by electron diffraction as early as in sixties (Abdel Aziz & Rogowski, 1964).The results showed molecular structures significantly different in two propanols (ccco-chain in trans-configuration for 1-propanol and tetrahedraangled to middle c-atom in 2-propanol). The first x-ray diffraction on liquid 1-propanol was reported in 1977 (Mikusinska-Planner, 1977) and molecular conformation was shown to be somewhat spherical in shape. The neutron diffraction works on liquid 2-propanol at low temperatures (190K-275K) were done by Howells et al (Zetterström et al, 1991(Zetterström et al, , 1994 with TOF (time of flight) neutron data.…”

Molecular conformation and structural correlations of liquid D-1-propanol through neutron diffraction

“…The differences in the conformation and structural correlations would be interesting. The X-ray scattering study to extract the structural parameters of liquid 1-propanol are available in the literature [4][5][6]. The X-ray data however have limitation of not locating hydrogen sites accurately.…”