Transition metal fullerene complex

(Redirected from Fullerene ligand) Chemical compounds containing spheroidical carbon compounds

Structure of C₆₀₂. Color code: green = Cl, blue = Ir, ochre = P

A transition metal fullerene complex is a coordination complex wherein fullerene serves as a ligand. Fullerenes are typically spheroidal carbon compounds, the most prevalent being buckminsterfullerene, C₆₀.

One year after it was prepared in milligram quantities in 1990, C₆₀ was shown to function as a ligand in the complex ₂Pt(η-C₆₀).

Since this report, a variety of transition metals and binding modes were demonstrated. Most transition metal fullerene complex are derived from C₆₀, although other fullerenes also coordinate to metals as seen with C₇₀Rh(H)(CO)(PPh₃)₂.

Binding modes

As ligands, fullerenes behave similarly to electron-deficient alkenes such as tetracyanoethylene. Thus, their complexes are a subset of metal-alkene complexes. They almost always coordinate in a dihapto fashion and prefer electron-rich metal centers. This binding occurs on the junction of two 6-membered rings. Hexahapto and pentahapto bonding is rarely observed.

In Ru₃(CO)₉(C₆₀), the fullerene binds to the triangular face of the cluster.

Illustrative Fullerene Complexes
₂Pt]₆(η-C₆₀)
Ru₃(CO)₉(C₆₀)
Platinum complex of isoxazoline-modified fullerene.

Examples

C₆₀ forms stable complexes of the type M(C₆₀)(diphosphine)(CO)₃ for M = Mo, W. A dirhenium complexes is known with the formula Re₂(PMe₃)₄H₈(η:ηC₆₀) where two of the hydrogen act as bridging ligands.

Many fullerene complexes are derived from platinum metals. An unusual cationic complex features three 16e Ru centers:

3 Cp*Ru(MeCN)₃ + C₆₀ → {₃C₆₀} + 3 MeCN

Vaska's complex forms a 1:1 adduct, and the analogous IrCl(CO)(PEt₃)₂ binds 200x more strongly. Complexes with more than one fullerene ligand are illustrated by Ir₄(CO)₃(μ₄-CH)(PMe₃)₂(μ-PMe)₂(CNCH₂Ph)(μ-η:ηC₆₀)(μ₄-η:η:η:ηC₆₀). In this Ir₄ cluster two fullerene ligands with multiple types of mixed binding. Platinum, palladium, and nickel form complexes of the type C₆₀ML₂ where L is a monodentate or bidentate phosphorus ligand. They are prepared by displacement of weakly coordinating ligands such as ethylene:

₂Pt(C₂H₄) + C₆₀ → ₂Pt(η-C₆₀) + C₂H₄

In ₆(η-C₆₀), six Pt centers are bound to the fullerene.

Modified fullerenes as ligands

Osmium tetraoxide adds to C₆₀ to give, in the presence of pyridine (py), the diolate C₆₀O₂OsO₂(py)₂.

The pentaphenyl anion C₆₀Ph₅ behaves as a cyclopentadienyl ligand.

In this example, the binding of the ligand is similar to ferrocene. The anion C₆₀(PhCH₂)₂Ph functions as an indenyl-like ligand.

Fullerenes can also be substituents on otherwise conventional ligands as seen with an isoxazoline fullerene chelating to platinum, rhenium, and iridium compounds.

Ongoing research

Although no application has been commercialized. non-linear optical (NLO) materials, and as supramolecular building blocks.

References

Alan L. Balch; Joong W. Lee; Bruce C. Noll; Marilyn M. Olmstead (1994). "Multiple Additions of Vaska-Type Iridium Complexes to C₆₀. Preferential Crystallization of the "Para" Double Addition Products: C₆₀{Ir(CO)Cl(PMe₃)₂}₂2C₆H₆ and C₆₀{Ir(CO)Cl(PEt₃)₂}2C₆H₆". Inorg. Chem. 33: 5238–5243. doi:10.1021/ic00101a015.
^ Alan L. Balch; Marilyn M. Olmstead (1998). "Reactions of Transition Metal Complexes with Fullerenes (C₆₀, C₇₀, etc.) and Related Materials". Chem. Rev. 98 (6): 2123–2166. doi:10.1021/cr960040e. PMID 11848962.
Krätschmer, W. (1990). "The infrared and ultraviolet absorption spectra of laboratory-produced carbon dust: evidence for the presence of the C₆₀ molecule". Chemical Physics Letters. 170 (2–3): 167–170. Bibcode:1990CPL...170..167K. doi:10.1016/0009-2614(90)87109-5.
Fagan, P.J.; Calabrese, J.C.; Malone, B. (1991). "The Chemical Nature of Buckminsterfullerene (C60) and the characterization of a platinum derivative". Science. 252 (5009): 1160–1161. Bibcode:1991Sci...252.1160F. doi:10.1126/science.252.5009.1160. ISSN 0036-8075. JSTOR 2876290. S2CID 95654230.
^ Denisovich, L. I.; Peregudova, S. M.; Novikov, Yu. N. (2010). "Electrochemical properties of transition metal complexes with C60 and C70 fullerene ligands (review)". Russian Journal of Electrochemistry. 46 (1): 1–17. doi:10.1134/S1023193510010015. S2CID 56103986.
^ Spessard, p. 162
Spessard, p. 165
Hsu, Hsiu-Fu; Shapley, John R. (1996). "Ru₃(CO)₉(μ₃-η,η,η-C₆₀): A Cluster Face-Capping, Arene-Like Complex of C₆₀". J. Am. Chem. Soc. 118 (38): 9192. doi:10.1021/ja962077m.
Fagan, P.J.; Calabrese, J.C.; Malone, B. (1991). "A multiply-substituted buckminsterfullerene (C60) with an octahedral array of platinum atoms". Journal of the American Chemical Society. 113 (24): 9408–9409. doi:10.1021/ja00024a079.
Toganoh, Motoki; Matsuo, Yutaka; Nakamura, Eiichi (2003). "Synthesis and catalytic activity of rhodium diene complexes bearing indenyl-type fullerene η5-ligand". Journal of Organometallic Chemistry. 683 (2): 295–300. doi:10.1016/S0022-328X(03)00465-0.
RamíRez-Monroy, Armando; Swager, Timothy M. (2011). "Metal Chelates Based on Isoxazolinefullerenes". Organometallics. 30 (9): 2464–2467. doi:10.1021/om200238a.
Dragonetti, Claudia; Valore, Adriana; Colombo, Alessia; Righetto, Stefania; Rampinini, Giovanni; Colombo, Francesca; Rocchigiani, Luca; MacChioni, Alceo (2012). "An investigation on the second-order NLO properties of novel cationic cyclometallated Ir(III) complexes of the type + (R=H, fulleridene) and the related neutral complex with the new 9-fulleriden-4-monoazafluorene ligand". Inorganica Chimica Acta. 382: 72–78. doi:10.1016/j.ica.2011.10.018.
Santos, Leandro J.; Carvalhoda-Silva, Dayse; Rebouças, Júlio S.; Alves, Marcos R.A.; Idemori, Ynara M.; Matencio, Tulio; Freitas, Rossimiriam P. (2011). "Synthesis of new porphyrin/fullerene supramolecular assemblies: A spectroscopic and electrochemical investigation of their coordination equilibrium in solution". Tetrahedron. 67: 228–235. doi:10.1016/j.tet.2010.10.066.

Bibliography

Spessard, Gary; Miessler, Gary (2010). Organometallic Chemistry ISBN 0195330994

v t e Organometallic chemistry
Principles	Crystal field theory Ligand field theory 18-electron rule d electron count Polyhedral skeletal electron pair theory Isolobal principle π backbonding Dewar–Chatt–Duncanson model Hapticity spin states Agostic interaction Metal–ligand multiple bond
Reactions	Oxidative addition / reductive elimination Migratory insertion β-hydride elimination Transmetalation Carbometalation
Types of compounds	Gilman reagents Grignard reagents Cyclopentadienyl complexes Transition metal indenyl complexes Transition metal fullerene complexes Metallocenes Metal tetranorbornyls Sandwich compounds Half sandwich compounds Transition metal acyl complexes Transition metal carbene complexes Transition metal carbyne complexes Transition metal alkene complexes Transition metal alkyne complexes Transition-metal allyl complexes Transition metal carbides Arene complexes of univalent gallium, indium, and thallium
Applications	Carbonylation Cativa process Grignard reaction Monsanto process Olefin metathesis Shell higher olefin process Ziegler–Natta process
Related branches of chemistry	Organic chemistry Inorganic chemistry Bioinorganic chemistry
Category Commons

v t e Coordination complexes
H donors:	H H₂
B donors:	BR₂ B_mH_n
C donors:	R RC(O) HC(O) CH₂＝CH-CH₂ C(CH₂)₃ CH₂＝CH₂ RC₂R C₆H₄ CN CO CO₂ C C₆R₆ C₆₀ & C₇₀ RNC =CR₂ ≡CR C₅H₅ C₉H₇
Si donors:	H_nSiR_4−n R₃Si
N donors:	NH₃ N₃ imidazole NO RNO NO₂ py amino acid N RN RCN bipy phen porphyrin (Me₃Si)₂N N₂ NCS
P donors:	PR₃ PR₂ PR₂OH
O donors:	H₂O R₂O RO O O₂ CO₃/HCO₃ C₂O₄ RCO₂ acac R₂CO ONO NO₃ ClO₄ C₅H₅NO OSR₂ SO₄ PO₄ OPR₃
S donors:	R₂NCS₂ RS R₂S R₂C₂S₂ SO₂ S₂O₃ SR₂O NCS
Halide donors:	F F₂ Cl Br I

Categories:

Misplaced Pages