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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 - PowerPoint PPT Presentation
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Manfred ScheerCoordination 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
Complexes Containing a Tungsten-Phosphorous Triple Bond
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
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
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
X-ray Structure
Eur. J. Inorg. Chem. 2005, 4023
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 Science 2003, 14, 299
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 Science 2003, 14, 299
Initial Attempts Attachment at edge or corner rather than at
the Fe2Q face
Journal of Cluster Science 2003, 14, 299
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 Science 2003, 14, 299
Reaction Pathways for M = Rh, Ir
Journal of Cluster Science 2003, 14, 299
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 Science 2003, 14, 299
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 Science 2003, 14, 299
X-ray Diffraction Studies
Journal of Cluster Science 2003, 14, 299
X-ray Diffraction Studies
Journal of Cluster Science 2003, 14, 299
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, 581J. Organometallic Chem. 2002, 658, 204
Reaction Scheme
Dalton Trans. 2003, 581
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, 581J. Organometallic Chem. 2002, 658, 204
1-D and 2-D Polymers
1-dimensional linear polymer forms immediately in CH3CN
Chem. Eur. J. 2005, 11, 2163
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
X-ray Diffraction
Chem. Eur. J. 2005, 11, 2163
X-ray Diffraction of Polymer Backbone
Chem. Eur. J. 2005, 11, 2163
31P MAS-NMR Spectra (X = Cl)
Chem. Eur. J. 2005, 11, 2163
31P MAS-NMR Spectra (X = I)
Chem. Eur. J. 2005, 11, 2163
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
31P MAS-NMR Spectral Analysis
Cp and CO Ligand Orientations
Chem. Eur. J. 2005, 11, 2163
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
Preparation of Phosphido Complexes[(RO)3W≡PM(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≡PW(CO)5]
Chem. Eur. J. 2001, 7, 1855
Trapping Reactions with Alkynes In situ generation of reactive intermediate
and reaction with alkynes
Chem. Eur. J. 2001, 7, 1855
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
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
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
31P{1H} NMR and X-ray Diffraction of Complex 5
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
31P{1H} NMR and X-ray Diffraction of Complexes 6 and 7
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