Isoelectronic Replacement of Si by P+: A Comparative Study of the Structures of the Spiro-cyclic EII Compounds E[C(PMe2)2(X)]2 (E = Si, Ge, Sn; X = PMe2, SiMe3) and a Novel Spirocyclic 10 e-Phosphorus Cation (PIII) P[C(PPh2)2(SiMe3)]2+

Hans H. Karsch, Eva Witt

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

Abstract

The synthesis of stable group 14 compounds E[(Me2P)2CX]2 (E = Si, Ge, Sn; X = PMe2, SiMe3) in the formal oxidation state + 2 is achieved by reacting ShCU/LiCioHs (GeCl2-dioxane and SnCl2) with LiC(PMe2)2(SiMe3), 1, and LiC(PMe2)3 (3) respectively. An X-ray structure analysis of Si[(Me2P)2C(SiMe3)]2 (2) Ge[(Me2P)3C]2 (4b) Sn[(Me2P)2C(SiMe3)]2 (5a) and Sn[(Me2P)3C]2 (5b) shows, that in the crystal, 2, 4b, 5a, b, have a distorted pseudo-trigonal-bipyramidal (ψ-tbp) structure, in which E (E = Si, Ge, Sn) as a spiro center, is surrounded by four phosphorus atoms. A common feature of the four compounds is also the marked difference between axial and equatorial element-phosphorus bond lengths. An analogous P+ compound P[(Ph2P)2C(SiMe3)]2+BPh4- was obtained by reaction of the triphosphete, 6, and (Cl)(Ph2)P=C(PPh2)(SiMe3), 7, with NaBPh4. The cation adopts a similiar ψ-tbp geometry as the E(II) compounds (E = Si, Ge, Sn), but differences are also important.

Original languageEnglish
Title of host publicationOrganosilicon Chemistry III
Subtitle of host publicationFrom Molecules to Materials
Publisherwiley
Pages65-69
Number of pages5
ISBN (Electronic)9783527619900
ISBN (Print)9783527620746
DOIs
StatePublished - 1 Jan 2008

Keywords

  • Phosphinomethanides
  • Phosphorus cation(P)
  • Spirocyclic E compounds

Fingerprint

Dive into the research topics of 'Isoelectronic Replacement of Si by P+: A Comparative Study of the Structures of the Spiro-cyclic EII Compounds E[C(PMe2)2(X)]2 (E = Si, Ge, Sn; X = PMe2, SiMe3) and a Novel Spirocyclic 10 e-Phosphorus Cation (PIII) P[C(PPh2)2(SiMe3)]2+'. Together they form a unique fingerprint.

Cite this