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YSU Jan 17th 2003. Matthias Zeller Properties and Reactivity of Triphospholyl-Metal-Complexes. What are Triphospholyl Complexes?. YSU Jan 17th 2003. Influence on: • structure • electronic properties • reactivity etc. YSU Jan 17th 2003. What can be modified?
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YSU Jan 17th 2003 Matthias Zeller Properties and Reactivity of Triphospholyl-Metal-Complexes
What are Triphospholyl Complexes? YSU Jan 17th 2003 Influence on: • structure • electronic properties • reactivity etc
YSU Jan 17th 2003 What can be modified? • Structure and Bonding Types Influence of free electron pair • Electronic Properties Degeneration of Frontier Orbitals, Sequence of Orbitals, Redox Potentials • Reactivity: Known Reactions Reaction Rate and Products Novel Reactions Stability and Decomposition Reactions
YSU Jan 17th 2003 What was known before: J. F. Nixon et al., J. Chem. Soc., Chem. Commun.1987, 373, 1146-1148; J. Organometal. Chem.1988, 365, C1-C4; J. Organometal. Chem. 1995, 490, 155-162; J. Organometal. Chem.1989, 373, C17-C20.
Our Starting Materials: YSU Jan 17th 2003 A. Elvers, F. Heinemann, B. Wrackmeyer, U. Zenneck, Chem. Eur. J. 1999, 5, 3143-3153.
YSU Jan 17th 2003 Some first new Compounds: A.Elvers, T. Clark, F. W. Heinemann, M. Hennemann, M. Zeller, U. Zenneck, Angew. Chem.2000, 112, 2174-2178; A. Elvers, F. W. Heinemann, B. Wrackmeyer, U. Zenneck, Chem. Eur. J. 1999, 5, 3143-3153.
YSU Jan 17th 2003 Paramagnetic 16 and 17 VE Complexes: Compare to R. Bartsch, P. B. Hitchcock, J. F. Nixon, J. Organometal. Chem. 1988, 356, C1-C4.
YSU Jan 17th 2003 EPR Spectra in n-Hexane: <g> = 2.007 <A(55Mn, I=5/2)> = 78.9 G rt 120 K, glassy frozen solution g = 1.996, A~ 0 G g = 2.029, A= 115.7 G
YSU Jan 17th 2003 Phosphorous in the Cp Ring Change of Orbital Sequence
YSU Jan 17th 2003 Redox Potential Shifts vs Cp2Cr the shifts are 1.7 to 2.0 V !
YSU Jan 17th 2003 Reduction of ´(P3C2)2Cr´ with K/Na: EPR Spectrum in Toluene: exp. sim.
YSU Jan 17th 2003 Triphospholyl Halfsandwich Complexes: Smp.: ~ -10°C
YSU Jan 17th 2003 Carbonyl Substitution under mild Conditions:
YSU Jan 17th 2003 Carbonyl Substitution under mild Conditions: Analogous Carbon Complex: 24 h Reflux in Hexane needed
YSU Jan 17th 2003 Analogous Carbon Complex: Only Monosubstitution with CN-Cy
YSU Jan 17th 2003 Carbonyl Substitution with P3-Cymantrene:
YSU Jan 17th 2003 31P NMR Spectrum:
YSU Jan 17th 2003 Analogous Carbon Complex: > 90 Minutes Irradiation needed for Disubstitution! Analogous Carbon Complex: No Reaction!
31P-NMR-Spectra at variable Temperatures: hindered Rotation of the Triphospholyl Ring (DH = 53 kJmol–1 ) YSU Jan 17th 2003
YSU Jan 17th 2003 Enhanced Reaction Rates: Why?
Triphospholyl Nickel Complexes YSU Jan 17th 2003 Compare.: But: See also: R. Bartsch, D.Carmichael, P. B. Hitchcock, M. F. Meidine, J. F. Nixon, G. J. D. Sillet, J. Chem. Soc., Chem. Commun.1988, 1615-1617.
A Nickel Nitrosyl Complex: YSU Jan 17th 2003 With Cyclopentadienyl:
A Reversible and Temperature Dependant --Rearrangement: YSU Jan 17th 2003 31P NMR Spectra:
Trapping of the Piano Stool Complex YSU Jan 17th 2003
What about Copper(I) Piano Stool Complexes? YSU Jan 17th 2003 +48°C +25°C -30°C -70°C -90°C
YSU Jan 17th 2003 An Equilibrium of three Isomers?
YSU Jan 17th 2003 Trapping with (OC)nW: Promotionsvortrag M. Zeller
YSU Jan 17th 2003 31P NMR Spectra at variable Temperatures:
1,2-Shift or 1,5-sigmatropic Rearrangement YSU Jan 17th 2003
YSU Jan 17th 2003 31P NMR Spectra at variable Temperatures:
YSU Jan 17th 2003 31P NMR Coupling Constants:
Is a Hexaphospha Mercurocene possible ? YSU Jan 17th 2003
YSU Jan 17th 2003 A Radical Elimination Reaction ? Vergl.: A. Mack, M. Regitz, Advances in Strained and Interesting Molecules, Suppl. 11999, 199.
YSU Jan 17th 2003 Under Irradition further Rearrangement occurs: Vergl.: A. Mack, M. Regitz, Advances in Strained and Interesting Molecules, Suppl. 11999, 199.
YSU Jan 17th 2003 31P NMR Spectrum:
YSU Jan 17th 2003 31P NMR Spectrum: Exp.: Sim.: 31P NMR Coupling Constants Y` Y X` X A` A 3.56 33.33 4.46 –86.42 63.74 X 29.55 –3.80 5.99 Y –6.74
YSU Jan 17th 2003 Summary: The Inclusion of Phosphorous Atoms in coordinated -Ligands influences the properties of the complexes remarkably They show, when compared to Complexes with pure carbacyclic Ligands Change of electronic properties (hexaphospha metallocenes), novel structural properties (Ni and Cu complexes), modified reactivity (CO substitution reactions), noveldecompostion reactions (hexaphospha mercurocene)
YSU Jan 17th 2003 Acknowledgements and Appreciations: Prof. Ulrich Zenneck, the Zenneck Group Dr. F. W. Heinemann (X-Ray), Dr. H. Pritzkow (X-Ray, Heidelberg), Dr. M. Moll (low temp NMR), PD Dr. W. Bauer (CP-MAS Spectra), Dr. O. Waldmann (SQUID-Measurements), Dr. G. Brehm und G. Sauer (Raman-Spectra), J. Kurzawa (UV-Vis-Spectra) Graduiertenkolleg ´Phosphorchemie als Bindeglied verschiedener Disziplinen´ ´StuSti´ (Studienstiftung des deutschen Volkes)