SYNTHESES AND CRYSTAL-STRUCTURE ANALYSES OF NEW ZWITTERIONIC SPIROCYCLIC (AMMONIOORGANYL)BIS[VIC-ARENEDIOLATO(2-)] SILICATES - STUDIES ON THE STRUCTURE OF THE LAMBDA-SI-5 COORDINATION POLYHEDRA

A new crystallographic modification (1-II) of the zwitterionic lambda( 5)Si-spirosilicate 3,4,5,6-tetrabromobenzene-1,2-diolato(2-)]silicate (1) was synthesized. In addition, two solvent-free crystallographic mo difications (2-I, 2-II) and two solvates (2 . Me(2)CO, 2 . MeNO(2)) of the zwitterionic lambda(5)Si-spirosilicate [(morpholinio)methyl] bis[ 2,3-naphthalenediolato(2-)]silicate (2) were prepared. All new compoun ds were studied by Si-29-CP/MAS NMR spectroscopy and compounds 1-II (P na2(1)), 2 . Me(2)CO (P2(1)/c), and 2 . MeNO(2) (P2(1)/n) were structu rally characterized by single-crystal X-ray diffraction.