Noninnocent behavior of PCP and PCN pincer ligands of late metal complexes

Elena Poverenov, David Milstein

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Pincer complexes are generally viewed as stable compounds in which the pincer ligand framework remains unchanged during stoichiometric and catalytic reactions. However, there are now several cases in which the pincer ligand itself undergoes transformations that result in extraordinary reactivity of the metal complex and formation of unusual species. In the current chapter, we review our work on noninnocent reactivity modes of various PCP and PCN-type pincer ligands of Rh, Ir, Ru, Os, Pd, and Pt. Participation of the arene ring in the reactivity of PCP type complexes has led to formation of unprecedented quinonoid complexes, including complexes in which the pincer ligand adopts structures of quinone methides, thio-quinone methides, xylylenes, methylene arenium, and oxo-arenium compounds. In addition, pincer systems can collapse and be regenerated under redox conditions, and reduction can lead to a ring-localized radical anion complex. The generation of C-H agostic arene PCP complexes has led to new insights regarding the C-H bond activation process, and the effect of CO ligands on it.

Original languageEnglish
Pages (from-to)21-48
Number of pages28
JournalTopics in Organometallic Chemistry
Volume40
DOIs
Publication statusPublished - 2013

Fingerprint

Pregnenolone Carbonitrile
Coordination Complexes
Metal complexes
Ligands
Carbon Monoxide
Anions
Negative ions
Chemical activation

Keywords

  • agnostic pincer complex
  • late transition metals
  • methylene arenium complex
  • phenoxonium complex
  • Pincer ligands
  • quinone methide complex
  • reactive intermediates
  • thioquinone methide complex
  • xylylene complex

ASJC Scopus subject areas

  • Organic Chemistry
  • Inorganic Chemistry
  • Catalysis

Cite this

Noninnocent behavior of PCP and PCN pincer ligands of late metal complexes. / Poverenov, Elena; Milstein, David.

In: Topics in Organometallic Chemistry, Vol. 40, 2013, p. 21-48.

Research output: Contribution to journalArticle

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