The Molecular Structure and Rotational Isomerization of n-Butane^1,2

The crystal and molecular structure of 2-(2',4'-dinitrobenzyl)pyridine

“…The C-C-C angle at the methylene carbon atom is 114.4 ° (with an e.s.d, of 0.4°), somewhat larger than the value 111.5 ° (1.0 °) found in a 2,2'-methylenediquinoline (Thuijl & Romers, 1966) and the values of 112.4 ° (0.2 °) in propane (Lide, 1960) and of 112.4 ° (0.3 °) in n-butane (Bonham & Bartell, 1959). The C-N bonds at the nitro group average 1.476 A with an r.m.s, deviation of 0.004 A, and the N-O bonds are 1.235 A with an r.m.s, deviation of 0.005 A.…”

The structure and orientational disorder in solid n-butane by neutron powder diffraction

“…The apparent C-H bond length is smaller by 1.5% at 90 than at 5 K. This shortening is caused by the 'swingarm' effect of rigid-body molecular librations, whereby the arc which is the locus of the deuterium position has a centroid closer to the carbon than the true bond length. The magnitude of this effect is probably sufficient to account for the discrepancy between this result, 1.087 (7)A, and the values obtained by electron diffraction (Kuchitsu, 1961;Bonham & Bartell, 1959) of 1.100 (3) and 1.108 (5) ,A,. Since the thermal motion is much less at 5 than at 90 K, the low-temperature values of the molecular dimensions are correspondingly more reliable.…”

“…The dimensions of the butane molecule in the gas phase have been determined by electron diffraction (Kuchitsu, 1961;Bonham & Bartell, 1959). One possible course of action would be to use this molecular geometry in a constrained refinement.…”

An electron diffraction study of the structures of thiophene, 2-chlorothiophene and 2-bromothiophene. A note

“…The HB procedure was followed as closely as possible (Bonham & Bartell, 1959). Their observed intensities were reproduced by careful reading of their photographically enlarged Figs.…”