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Manfred Scheer Coordination Chemistry of Phosphorous Containing Compounds

Manfred Scheer Coordination Chemistry of Phosphorous Containing Compounds. Angela Dann May 8, 2006. Research Interests. Supramolecular Arrays Fullerene-like nanoballs Heteronuclear clusters with main group metal incorporation 1-Dimensional and 2-Dimensional Polymers

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Manfred Scheer Coordination Chemistry of Phosphorous Containing Compounds

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  1. Manfred ScheerCoordination Chemistry of Phosphorous Containing Compounds Angela Dann May 8, 2006

  2. Research Interests • Supramolecular Arrays • Fullerene-like nanoballs • Heteronuclear clusters with main group metal incorporation • 1-Dimensional and 2-Dimensional Polymers • Complexes Containing a Tungsten-Phosphorous Triple Bond

  3. Fullerene-like Nanoballs [CpxFe(η5-P5)] + CuIX Cpx = η5-C5Me5, η5-C5Me4Et X = Br, Cl, I • Soluble nanoballs form along with insoluble 1-D and 2-D polymers • Contain 90 non-carbon atoms Eur. J. Inorg. Chem. 2005, 4023

  4. Reaction Conditions • Mixed solvent system: CH3CN and CH2Cl2 • Soluble product formed upon increasing dilution (15 mmol/L  7.5 mmol/L) • Negligible amount of polymer formed with dilution of 3.75 mmol/L • 2:1 optimum stoichiometry of CuBr:[CpxFe(η5-P5)] x = η5-C5Me5 or η5-C5Me4Et Eur. J. Inorg. Chem. 2005, 4023

  5. Structural Analysis • Black crystals • Broad 31P NMR chemical shifts at 66 and 68 ppm • X-ray diffraction – P atoms coordinate to Cu atoms on both sides of CuBr • Core symmetry is D5h • Ethyl groups attached to Cp decrease symmetry to Cs

  6. X-ray Structure Eur. J. Inorg. Chem. 2005, 4023

  7. Heteronuclear Clusters Incorporating Main Group Elements • Elevated synthetic and applied potential • Increased stability upon addition of main group element • 1st example of electrophilic addition of a Cp*M2+ unit to an Fe2Q face of a cluster M = Rh, Ir Q = S, Se, Te Journal of Cluster Science2003, 14, 299

  8. Reaction Scheme [Fe3(μ3-Q)(CO)9][NEt4]2 + [Cp*M(CH3CN)3][CF3SO3]2 M = Rh, Ir Q = S, Se, Te Journal of Cluster Science2003, 14, 299

  9. Initial Attempts • Attachment at edge or corner rather than at the Fe2Q face Journal of Cluster Science2003, 14, 299

  10. Addition to the Fe2Q Face • Two possible reaction pathways • Closo structure with a μ3-Q ligand – 60e • Butterfly-shaped structure with a μ4-Q ligand – 62e • M = Rh – butterfly-shaped structure only • M = Ir – major product with butterfly-shaped structure, minor product with closo structure Journal of Cluster Science2003, 14, 299

  11. Reaction Pathways for M = Rh, Ir Journal of Cluster Science2003, 14, 299

  12. Structural Analysis • Black crystals • Soluble in toluene, CH2Cl2, and THF • IR – when Q = Se, peaks shifted to higher frequencies than for Q = Te • Mass spectra – characteristic fragments along with sequential loss of CO units Journal of Cluster Science2003, 14, 299

  13. CO Flexibility Examined by IR • In hexane – group of peaks between 2060 and 1900 cm-1 indicates terminal CO groups • One signal for the CO groups in 13C NMR suggests high flexibility in solution • In Nujol – peaks below 1900 cm-1 indicate semi-bridging CO groups • Confirmed by X-ray diffraction Journal of Cluster Science2003, 14, 299

  14. X-ray Diffraction Studies Journal of Cluster Science2003, 14, 299

  15. X-ray Diffraction Studies Journal of Cluster Science2003, 14, 299

  16. Electrophilic Attack by REX2 • Incorporation of group 15 elements • E = As, Sb • Variations of R-group to create stabilized functionalized clusters • [Fe3(μ3-Q)(CO)9]K2 used rather than [Fe3(μ3-Q)(CO)9][NEt4]2 to produce pure products Dalton Trans.2003, 581 J. Organometallic Chem. 2002, 658, 204

  17. Reaction Scheme Dalton Trans.2003, 581

  18. Structural Analysis • X-ray diffraction – nido clusters • Square FeEFeQ unit capped by Fe fragment E = As, Sb Q = Se, Te • Only 1:1 stoichiometry gives desired product Dalton Trans.2003, 581 J. Organometallic Chem. 2002, 658, 204

  19. 1-D and 2-D Polymers • 1-dimensional linear polymer forms immediately in CH3CN Chem. Eur. J.2005, 11, 2163

  20. Structural Analysis • Red crystalline solid • Air and light sensitive • Very insoluble • IR – stretching frequencies indicate terminal CO groups • X-ray – small differences in ligand orientation Chem. Eur. J.2005, 11, 2163

  21. X-ray Diffraction Chem. Eur. J.2005, 11, 2163

  22. X-ray Diffraction of Polymer Backbone Chem. Eur. J.2005, 11, 2163

  23. 31P MAS-NMR Spectra (X = Cl) Chem. Eur. J.2005, 11, 2163

  24. 31P MAS-NMR Spectra (X = I) Chem. Eur. J.2005, 11, 2163

  25. 31P MAS-NMR Spectral Analysis • X = Br, Cl – two multiplets separated by about 150 ppm • Homonuclear 1J(31P, 31P) spin-spin interactions • Heteronuclear 1J(63/65Cu, 31P) interactions • X = I – broad signal • Result of differences in orientation of Cp and CO ligands Chem. Eur. J.2005, 11, 2163

  26. Cp and CO Ligand Orientations Chem. Eur. J.2005, 11, 2163

  27. Additional Reactions • Reactions with CuCl2 and CuBr2 also attempted • Red needle-like crystals • Yielded same products as CuCl and CuBr • Reduction of CuIIX occurs • CuIX complexes obviously represent the thermodynamic minimum Chem. Eur. J.2005, 11, 2163

  28. Preparation of Phosphido Complexes [(RO)3W≡PM(CO)5] R = tBu, 2,4,6-Me2C6H3 M = Cr, W • Lone pair of electrons on P coordinated by M(CO)5 to increase stability • Thermolysis reaction of [Cp*P{W(CO)5}2] • C-H activation followed by loss of CO leads to reactive intermediate [Cp*(CO)2W≡PW(CO)5] Chem. Eur. J.2001, 7, 1855

  29. Trapping Reactions with Alkynes • In situ generation of reactive intermediate and reaction with alkynes Chem. Eur. J.2001, 7, 1855

  30. Structural Analysis • Black (4, 5), yellow (6), and red (7) crystalline solids • IR – stretching frequencies of terminal CO groups • 31P{1H} NMR and X-ray diffraction studies Chem. Eur. J.2001, 7, 1855

  31. 31P{1H} NMR and X-ray Diffraction of Complex 4 • Two singlets correspond to chemically non-equivalent P atoms not coupled through W atom • Two 183W satellites per singlet • Larger 1J(183W, 31P) value corresponds to bonding of P to W(CO)5 Chem. Eur. J.2001, 7, 1855

  32. 31P{1H} NMR and X-ray Diffraction of Complex 5 • Two doublets correspond to chemically non-equivalent P atoms • 1J(31P, 31P) = 407 Hz • P-P multiple bond • No coupling of P atoms to W atoms Chem. Eur. J.2001, 7, 1855

  33. 31P{1H} NMR and X-ray Diffraction of Complexes 6 and 7 • Complex 6 – singlet with two 183W satellites • Larger 1J(183W, 31P) value corresponds to bonding of P to W(CO)5 • Complex 7 – singlet with one 183W satellite Chem. Eur. J.2001, 7, 1855

  34. Reaction Pathway • Thermolysis of [Cp*P{W(CO)5}2] leads to: • Cp* migration • C-H activation • CO elimination • [2+2] cycloadditions with an alkyne • Stabilization of the [WPC2] ring - Reaction with W-CO unit (complex 6) - Reaction with 2nd unit of the intermediate (complex 4) Chem. Eur. J.2001, 7, 1855

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