Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)methanide Ligands. Issue 23 (8th April 2013)

• Record Type: Journal Article
• Authors: Haehnel, Martin; Hansen, Sven; Priebe, Jacqueline B.; Spannenberg, Anke; Arndt, Perdita; Brückner, Angelika; Rosenthal, Uwe
• Is Part Of: Chemistry. Volume 19:Issue 23(2013)
• Page Start: 7568
• Page End: 7574
• Publication Date: 2013-04-08
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201300218
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A study of the coordination chemistry of different bis(diphenylphosphino)methanide ligands [Ph<sub>2</sub>PC(X)PPh<sub>2</sub>] (X=H, SiMe<sub>3</sub>) with Group 4 metallocenes is presented. The paramagnetic complexes [Cp<sub>2</sub>Ti{κ<sup>2</sup>‐<italic>P</italic>, <italic>P</italic>‐Ph<sub>2</sub>PC(X)PPh<sub>2</sub>}] (X=H (<bold>3 a</bold>), X=SiMe<sub>3</sub> (<bold>3 b</bold>)) have been prepared by the reactions of [(Cp<sub>2</sub>TiCl)<sub>2</sub>] with [Li{C(X)PPh<sub>2</sub>}<sub>2</sub>(thf)<sub>3</sub>]. Complex <bold>3 b</bold> could also be synthesized by reaction of the known titanocene alkyne complex [Cp<sub>2</sub>Ti(η<sup>2</sup>‐Me<sub>3</sub>SiC<sub>2</sub>SiMe<sub>3</sub>)] with Ph<sub>2</sub>PC(H)(SiMe<sub>3</sub>)PPh<sub>2</sub> (<bold>2 b</bold>). The heterometallacyclic complex [Cp<sub>2</sub>Zr(H){κ<sup>2</sup>‐<italic>P</italic>, <italic>P</italic>‐Ph<sub>2</sub>PC(H)PPh<sub>2</sub>}] (<bold>4 aH</bold>) has been prepared by reaction of the Schwartz reagent with [Li{C(H)PPh<sub>2</sub>}<sub>2</sub>(thf)<sub>3</sub>]. Reactions of [Cp<sub>2</sub>HfCl<sub>2</sub>] with [Li{C(X)PPh<sub>2</sub>}<sub>2</sub>(thf)<sub>3</sub>] gave the highly strained corresponding metallacycles [Cp<sub>2</sub>M(Cl){κ<sup>2</sup>‐<italic>P</italic>, <italic>P</italic>‐Ph<sub>2</sub>PC(X)PPh<sub>2</sub>}] (<bold>5 aCl</bold> and <bold>5 bCl</bold>) in very good yields. Complexes <bold>3 a</bold>, <bold>4 aH</bold>, and <bold>5 aCl</bold> have been characterized by X‐ray crystallography. Complex <bold>3 a</bold> has also been characterized by EPR spectroscopy. The structure and bonding of the complexes has been investigated by DFT analysis. Reactions of complexes <bold>4 aH</bold>, <bold>5 aCl</bold>, and <bold>5 bCl</bold> did not give the corresponding more unsaturated heterometallacyclobuta‐2, 3‐dienes.</p> </abstract>