New Chiral Zwitterionic λ5Si-Silicates with an SiO5 or SiO4C Framework: Syntheses, Crystal Structures, and Properties

✍ Scribed by Reinhold Tacke; Brigitte Pfrommer; Melanie Pülm; Rüdiger Bertermann

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 430 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199905)1999:5<807::aid-ejic807>3.0.co;2-y

✦ Synopsis

The syntheses of the zwitterionic (molecular) spirocyclic λ 5 Si-connect the ate and onium center of these zwitterions.

Compound 7, 8, and 10-12 were studied by single-crystal X-silicates 7 and 8 (SiO 5 skeletons) and 10-12 (SiO 4 C skeletons) are described. These chiral compounds contain a ray diffraction, solution-state ( 1 H, 13 C, 29 Si) and solid-state ( 29 Si CP/MAS) NMR spectroscopy, and VT 1 H-NMR pentacoordinate (formally negatively charged) silicon atom and a tetracoordinate (formally positively charged) nitrogen spectroscopy. The experimental investigations were completed by ab initio studies of the related anionic λ 5 Si-atom. The pairs 7/11 and 8/12 are isoelectronic O/CH 2 analogues and 10-12 represent a series of homologous silicate 13. compounds containing different alkylene spacers that

The spirocyclic anions of 1Ϫ5 contain two bidentate ligands