Solid-solid interactions—III

The crystal structure of the 1:5 calcium perchlorate–diacetamide complex

“…The antiprismatic arrangement of the ligand atoms surrounding the Ca ions is similar to that found in the CaBr2.4DA complex (Roux & Boeyens, 1970). The three main deductions made by Gentile & Shankoff (1965) The trans-trans configuration of acetamide is less stable than the trans-cis configuration owing to repulesiv forces between the two carbonyl O atoms Uno, Machida & Hamanaka 1961). One would therefore expect to find the DA molecule not acting as a bidentate ligand to be in the trans-cis configuration with its C-O bonds tending to ion-dipole interaction with the neighbouring cations as is the case with the uncoordinated DA molecule in this structure.…”

“…2DA, KI.2DA and CaBr2.4DA (Roux & Boeyens, 1969a, b, 1970. According to Gentile & Shankoff (1965) the infrared spectra of the complexes Ca(CIO4)2.5DA and Ba(C104)2.5DA indicated monodentation, non-planarity and configuration intermediate between the trans-trans and cis-trans forms for one of the DA molecules. They concluded that the data were in support of an unusual coordination number of nine.…”

“…The preparation of the complexes of diacetamide (CH3CO.NH.COCH3, DA) with alkali and alkaline earth metal salts was described by Gentile & Shankoff (1965). The main features of these complexes were explained by the structure determinations of NaBr.…”

Valence-bond studies of contact nuclear spin-spin coupling. III. .pi.-Electron coupling in aromatic and cyclic unsaturated hydrocarbons

“…In the triplet manifold configurational mixing occurs between a given triplet, 3 ). ", and those which are obtained by exciting to the triplets of group S. For the m = 0 component of the R group triplets, the most general expression is 3%, = + ,,3 , + (6) with energy 3EP and coefficients obtained from diagonalizing the secular determinant.5 An expression analogous to eq 6 is obtained for the S group triplets.…”

Metal Ion Complexation of Model Imides

“…1-4 [he spectra of _etal ion-in-ide complexes have also been recently examined [5][6][7][8][9][10] These studies all involved acyclic symmetrical irnides (e. g. , diacetamides), and we do not believe that such studies have been reported using acyclic unsymmetrical or cyclic imides. The interesting feature is that serveral metal complexes are Spossiblj .ilnce four configarations (A-D) can uauilly be written.…”