Do corresponding coupling constants in hydrogen-bonded homo- and hetero-chiral dimers differ?

Abstract

Ab initio equation-of-motion coupled cluster singles and doubles (EOM–CCSD) calculations have been carried out to evaluate spin–spin coupling constants in six pairs of homo- and hetero-chiral dimers: (HOOH)2, (H2NNH2)2, (FOOH)2, (FHNNH2)2, (HOOOH)2, and (FOOOH)2. Corresponding spin–spin coupling constants in these isomeric pairs of C2and Cisymmetry may differ, but these differences are small and may not be detectable experimentally. For the complexes with O1–H···O and O1–H···F hydrogen bonds,1J(O1–H) has a larger absolute value in the C2isomer. For the same set of complexes,1J(O1–O2) has a larger absolute value in the Ciisomer. No distinguishable patterns could be discerned in the remaining spin–spin coupling constants in the C2and Ciisomers of these complexes, nor in complexes with N–H···N hydrogen bonds.