The molecular structure of
N,N,N',N',2,2-hexamethylpropanediamide has been determined in the solid state
by X-ray diffraction methods. The structure of Me2NCOCMe2CONMe2
may be broadly described as two planar Me2NCO entities intersecting
at the tetrahedral -CMe2- site. The angle between the normals to the two Me2NCO planes is 104.6�, and
the two oxygen atoms are disposed outwards from the molecule and away from each
other. Proton (270-MHz) n.m.r. studies yield k(320 K) 32.0 � 3.2 s-1,
ΔH‡ 69.5 � 0.4 kJ mol-1 and ΔS‡ 0.6 � 1.1 J K-1
mol-1 for rotation of the N-methyl groups about the carbon-nitrogen
bonds in CD3NO2 solution. Similar magnitudes for the
kinetic parameters characterizing this process are obtained in CDCl3,
and CD3CN solutions.
Molecular structure and infrared spectra of dimethyl oxalateElectronic Supplementary Information available. See http://www.rsc.org/suppdata/cp/b1/b107232n/