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Reactivity of bridging Pentelidene Complexes

Reactivity of bridging Pentelidene Complexes. Contents:. Overview on phosphinidene complexes General reactivity pattern Reactivity towards diphosphenes Reactivity towards primary phosphines. Phosphinidene complexes :.  1. µ 2. µ 3. µ 4. M. Ruiz, A. J. Carty.

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Reactivity of bridging Pentelidene Complexes

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  1. ReactivityofbridgingPentelideneComplexes

  2. Contents: • Overview on phosphinidene complexes • General reactivity pattern • Reactivity towards diphosphenes • Reactivity towards primary phosphines

  3. Phosphinidenecomplexes: 1 µ2 µ3 µ4 M. Ruiz, A. J. Carty G. Huttner et al, Acc. Chem. Res. 1986, 19, 406-413 M. F. Lappert 1979 A. H. Cowley 1990 stablecompoundswithbulkysubstituents R orbulkyligands Cowley, Lappert, Wolczanski, Schrock, Hey-Hawkins intermediates withlessbulkysubstituents R Mathey, Lammertsma, Streubel

  4. Preparation: 31P: δ= 1076 ppm (s,1JWP = 166 Hz,187 Hz) Jutziet al., J. Organomet. Chem.1990, 390, 317-322.

  5. sp2-hybridisation at the phosphorus atom • phosphinidene as m2-4e--ligand • p-back bonding from the metal to the P atom a3-centre-4p-electron system Bondsituation: LUMO -4.28eV HOMO -5.45eV

  6. Reactivitypattern: Cp* migration Cp* shift Cp* ring expansion Cp* elimination nucleophilicattack

  7. Thermolysis: Scheer et al., Chem. Eur. J.1998, 4, 1917-1923.

  8. Photolysis: Scheer et al., Eur. J. Inorg. Chem.2001, 1661-1663.

  9. Photolysiswithdiphosphenes: P1 P1 P1 P1` P2 As1 d(P1-As1) = 2.216(1) Å d(P1-P2) = 2.1122(10) Å M. Scheer, C. Kuntz, M. Stubenhofer, M. Linseis, R.Winter, M. Sierka,Angew. Chem. Int. Ed. 2009, 48, 2600 –2604.

  10. Photolysiswithdiphosphenes: P2 As1 P3 P1 P1 P2 H1 H1 d(P1-P2) = 2.187(3) Å d(P2-P3) = 2.075(3)Å d(P1-As1) = 2.179(2) Å d(P2-As1) = 2.298(2)Å radical: d(P1-P2) = 2.1122(10) Å radical: d(P1-As1) = 2.216(1) Å

  11. Cyclovoltammogram: E½ (Ox.) = 0.17 V E½ (Ox.) = 0.17 V E½ (Red.) = –0.81 V E½ (Red.) = –0.81 V rate ofspeed: 100 mV/s

  12. Oxidation andreduction: P3 P1 P1 P2 P2 As1 bondlength: d(P1-P2) = 2.070 (3) Å d(P2-P3) = 2.065 (3) Å bondlength: d(P1-As1) = 2.186(3) Å d(P2-As1) = 2.191(2) Å

  13. Oxidation andreduction: P2 P3 P1 bondlength: d(P1-P2) = 2.256 (7) Å d(P2-P3) = 2.085 (6) Å

  14. Summary: M. Stubenhofer, C. Kuntz, M. Bodensteiner, U. Zenneck, M. Sierka, M. Scheer Chem. Eur. J.2010, 13, 1745-1747 .

  15. Reactivitytowardsprimaryphosphines: N1 N1 P2 B1 P1 R = H2P-BH2NMe3 B1 P1 As1 d(P1-P2) = 2.237(2) Å d(As1-P1) = 2.352(3) Å M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. Int. Ed. 2010, 49, 188 –192.

  16. Reactivitytowardsprimaryphosphines: R = Ph P1 P2 d(P1-P2) = 2.197(1) Å M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. Int. Ed. 2010, 49, 188 –192.

  17. Reactivitytowardsprimaryphosphines: R = Ph M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. Int. Ed. 2010, 49, 188 –192.

  18. Reactivitytowardsprimaryphosphines: P1 H1 P2 d(P1-P2) = 2.239(2) Å DFT-methods (B3LYP/6-31G* (ECP for W)) M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. Int. Ed. 2010, 49, 188 –192.

  19. Reactivity towards primaryphosphines: R =tBu M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. Int. Ed. 2010, 49, 188 –192.

  20. Reactivitytowardsprimaryphosphines: As1 P3 P2 P1 P1 P2 d(P1-As1) = 2.334(3) Å d(As1-P2) = 2.369(3) Å 31P{1H}-NMR: symd = -17.2 ppm asymd = -20.8 ppm (d, 2JP,P = 3Hz) d = -18.7 ppm (d, 2JP,P = 3Hz) d(P1-P2) = 2.215 (2) Å d(P2-P3) = 2.238(2) Å 31P{1H}-NMR: d= -90.7 ppm (dd, 1JP,P = 197 Hz d = -13.4 ppm (d, 1JP,P = 197 Hz)

  21. Reactivitytowardsprimaryphosphines:

  22. M. Stubenhofer, C. Kuntz, G.Balázs, M. Zabel, M. Scheer, Chem. Commun. 2009, 13, 1745 – 1747.

  23. Acknowledgement: • Prof. Manfred Scheer • Scheer Group • DFG

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