Transcript Manfred Scheer Coordination Chemistry of Phosphorous

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

Complexes Containing a TungstenPhosphorous 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(η5P5)]
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(μ3Q)(CO)9][NEt4]2 to produce pure products
Dalton Trans. 2003, 581
J. 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, 581
J. 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
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
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≡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
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 nonequivalent 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
31P{1H}

NMR and X-ray Diffraction
of Complex 5
Two doublets correspond to chemically nonequivalent P atoms
 1


J(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 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
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