@article{TackeBechtLopezMrasetal.1993,
  author    = {Tacke, Reinhold and Becht, J. and Lopez-Mras, A. and Sheldrick, W. S. and Sebald, A.},
  title     = {Syntheses, X-ray crystal structure analyses, and solid-state NMR studies of some zwitterionic organofluorosilicates},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64272},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{TackeLopezMrasSheldricketal.1993,
  author    = {Tacke, Reinhold and Lopez-Mras, A. and Sheldrick, W. S. and Sebald, A.},
  title     = {Synthesen, Einkristall-R{\"o}ntgenstrukturanalysen und \(^{29}\)Si-Festk{\"o}rper-NMR-Untersuchungen eines zwitter- ionischen \(\lambda_5\)-Spirosilicats und eines k{\"a}figartigen Octa(silasesquioxans) : [Professor Hartmut B{\"a}rnighausen zum 60. Geburtstage gewidmet]},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64243},
  year      = {1993},
  abstract  = {No abstract available},
  subject      = {Anorganische Chemie},
  language  = {de}
}
@article{TackeLopezMrasSperlichetal.1993,
  author    = {Tacke, Reinhold and Lopez-Mras, A. and Sperlich, J. and Strohmann, C. and Kuhs, W. F. and Mattern, G. and Sebald, A.},
  title     = {Neue zwitterionische \(\lambda_5\)-Spirosilicate: Synthesen, Einkristall-R{\"o}ntgenstrukturanalysen und Festk{\"o}rper-NMR-Untersuchungen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64251},
  year      = {1993},
  abstract  = {The zwitterionic spirocyclic \(\lambda_5\) -Silicates bis(3,4,5,6-tetrabromo- 1,2-benzenediolato(2- ))[2-(pyrrolidinio)ethyl]silicate (5; and its monohydrate 5 · H\(_2\)O) and bis[1,2-benzenediolato(2- )][( dimethylammonio)methyl]silicate (6) were synthesized by various methods including Si-C bond cleavage reactions. The crystal structures of 5, 5 · H\(_2\)O, and 6 were investigated by Xray d{\"u}fraction. Furthermore, 5, 5 · H\(_2\)O, 6, and the related zwitterionic \(\lambda_5\)-spirosilicates 1 · 1/4 CH\(_3\)CN, 2 · CH\(_3\)CN, 3 · CH\(_3\)CN, and 4 were characterized by solid-state NMR spectroscopy (\(^{29}\)Si and \(^{15}\)N CP/MAS). The pentacoordinate silicon atoms of 5, 5 · H\(_2\)O (two crystallographically independent ZWitterions and two crystallographically independent water molecules), and 6 (two crystallographically independent zwitterions) are surrounded by four oxygen atoms and one carbon atom. The coordination polyhedrons around the silicon atoms of 5 and 6 can be described as distorted (5) or nearly ideal (6) trigonal bipyramids, the carbon atoms being in equatorial positions. 5 forms intramolecular and 6 intermolecular (--+ formation of dimeric units) N- H···O hydrogen bonds. The coordination polyhedrons around the two crystallographically independent silicon atoms of 5 · H\(_2\)O can be described as a nearly ideal and slightly distorted square pyramid, respectively, the carbon atoms being in the apical positions. In the crystal lattice of 5 · H\(_2\)O, intermolecular N-H···O and 0-H···O hydrogen bonds between the zwitterions and water molecules are observed. The results obtained by X-ray diffraction and solid-state NMR spectroscopy are consistent for each compound studied.},
  subject      = {Anorganische Chemie},
  language  = {de}
}