In a study preceeding the investigation of a novel class of inclusion compounds, the lowtemperature crystal structure o f the host-m olecule N ,N ’-ditosyl-p-phenylenediamine has been determined. It crystallizes in the monoclinic space group P21/N with two formula units in the unit cell, forming layers of hydrogen-bonded molecules. The essential subunits are rigid phenyl rings and flexible sulfonamide linkages C -N(H)-S(O2)-C, the conformations o f which are discussed by comparison with data from the Cambridge Structural Database and based on density functional theory (DFT) as well as semiempirical PM3 calculations for the selected model compounds, N-methyl-methane-, N-methyl-benzene- and N-phenyl-methane-sulfonamide. The torsion angle dependent energy and enthalpy profiles allow estimates o f the rotational barriers around the C -S-N -C bonds. In addition, potential hydrogen bonding by the host molecule is discussed in comparison to analogous carbonic acid derivatives.
Predicting the thermal conductivity of pyrochlore and defect fluorite nuclear waste forms using experimental data and density functional theory simulations