title: Liquid structure of dibutyl sulfoxide.
abstract: We present experimental (X-ray diffraction) data on the structure of liquid dibutyl sulfoxide at 320 K and rationalise the data by means of molecular dynamics simulations. Not unexpectedly, DBSO bearing a strong dipolar moiety and two medium length, apolar butyl chains, this compound was characterised by a distinct degree of polar vs. apolar structural differentiation at the nm spatial scale, which was fingerprinted by a low Q peak in its X-ray diffraction pattern. Similar to, but to a larger extent than its shorter chain family members (such as DMSO), DBSO was also characterised by an enhanced dipole-dipole correlation, which was responsible for a moderate Kirkwood correlation factor as well as for the self-association detected in this compound. We show, however, that the supposedly relevant hydrogen bonding correlations between oxygen and the butyl chain hydrogens are of a limited extent only, and only in the case of α-hydrogens is an appreciable indication of the existence of such an interaction found, albeit this turned out to be a mere consequence of the strong dipole-dipole correlation.
authors.affiliation: Dipartimento di Fisica e Chimica, viale delle Scienze, Palermo, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Lo Celso
authors.forename: Bachir
authors.initials: B
authors.lastname: Aoun
authors.forename: Alessandro
authors.initials: A
authors.lastname: Triolo
authors.forename: Olga
authors.initials: O
authors.lastname: Russina