Exploring the conformations of Dibutyl Phosphonate (DBP): A matrix isolation infrared spectroscopic and density functional theory studies

Abstract

Dibutyl phosphonate (DBP) has been subjected to conformational analysis using matrix isolation infrared spectroscopy and computational methodology using B3LYP level of theory with 6–311++G(d,p) basis set. The Boltzmann population distribution predicted by the computations is validated using infrared spectroscopy of DBP isolated within matrixes of Ne, N2, Ar and Xe at cryogenic temperatures. The strategy of systematically reducing the number of possible orientations of alkoxy strands, previously used for tri-alkyl phosphates, is applicable to phosphonates also. The conformational landscape of DBP dominated by the ‘Gauche’ forms in comparison to tri-alkyl phosphates with competing distribution of ‘Trans’ isomers has been distinctly unravelled using the results of natural bond orbital analysis.