A DATABASE STUDY OF THE BONDING AND CONFORMATION OF BIS-SULFONYLAMIDES AND IMIDES. By Alajos Kálmán* and Petra Bombicz, Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1525 Budapest 114, P.O.Box 17., Hungary.
The bonding and conformational characteristics of bis-sulfonylamides and analogous imides are compared. Structures (44 altogether) of type R-SO2-NQ-SO2-R' (R, R' = Me, Et, or Aryl) were retrieved from the Cambridge Structural Database (March 1994 release, 120481 entries). They are either neutral (Q = H, alkyl and aryl group or hetero atom like O and S) or charged (Q = e- or metal, like In, Hg, etc.).
Analysis of the S-N bonds varying in the range 1.57-1.76 Å and their observed influence upon the other S-X and X-S-Y parameters enabled us:
i. to characterize the S-N bonds against the differences in the nitrogen enviroment (charged N, N-metal and N-covalent bonds),
ii. to prove the applicability of the bond order conservation principle (Johnston, 1961) and the VSEPR rules (Gillespie, 1963) on the S(VI)[O,O',N,C] tetrahedra,
iii. to describe the intra- and intermolecular conditions of the folded conformation vs the energetically favourable open form of the C-SO2-NQ-SO2-C moieties,
iv. and to substantiate the inequalities of the O-S-N angles which is attributable to the synclinal position of one of the S-O bonds with N-lone pair (Kálmán et al., 1981).
The marked difference between the archetypes of the S-N bonds indicates that the interdependence of the S-X bonds in the NSO2C tetrahedra are principally governed by the environment of the nitrogen atoms. (Sponsor: Hungarian Res. Fund, Grant No. OTKA T014539).
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