One year after it was prepared in milligram quantities in 1990,[3] C60 was shown to function as a ligand in the complex [Ph3P]2Pt(η2-C60).[4]
Since this report, a variety oftransition 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.[5]
As ligands, fullerenes behave similarly toelectron-deficientalkenes such astetracyanoethylene. Thus, their complexes are a subset ofmetal-alkene complexes. They almost always coordinate in adihapto fashion and prefer electron-rich metal centers.[6] This binding occurs on the junction of two 6-membered rings. Hexahapto and pentahapto bonding is rarely observed.[7]
In Ru3(CO)9(C60), the fullerene binds to the triangular face of the cluster.[8]
Illustrative Fullerene Complexes
[[Ph3P]2Pt]6(η2-C60)
Ru3(CO)9(C60)
Platinum complex of isoxazoline-modified fullerene.
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(η2:η2C60) where two of the hydrogen act as bridging ligands.[5]
Many fullerene complexes are derived from platinum metals. An unusual cationic complex features three 16e Ru centers:
Vaska's complex forms a 1:1 adduct, and the analogous IrCl(CO)(PEt3)2 binds 200x more strongly.[2] Complexes with more than one fullerene ligand are illustrated by Ir4(CO)3(μ4-CH)(PMe3)2(μ-PMe)2(CNCH2Ph)(μ-η2:η2C60)(μ4-η1:η1:η2:η2C60). In this Ir4 cluster two fullerene ligands with multiple types of mixed binding. Platinum, palladium, andnickel form complexes of the type C60ML2 where L is a monodentate or bidentatephosphorus ligand.[5] They are prepared by displacement of weakly coordinating ligands such asethylene:[6]
[Ph3P]2Pt(C2H4) + C60 → [Ph3P]2Pt(η2-C60) + C2H4
In [(Et3P)2Pt]6(η2-C60), six Pt centers are bound to the fullerene.[9]
In this example, the binding of the ligand is similar toferrocene. The anion C60(PhCH2)2Ph functions as anindenyl-like ligand.[10]
Fullerenes can also be substituents on otherwise conventional ligands as seen with an isoxazoline fullerene chelating to platinum,rhenium, andiridium compounds.[11]
^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}2.2C6H6 and C60{Ir(CO)Cl(PEt3)2}2.C6H6".Inorg. Chem.33:5238–5243.doi:10.1021/ic00101a015.
^abcAlan 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.PMID11848962.
^abcdDenisovich, 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.S2CID56103986.
^Hsu, Hsiu-Fu; Shapley, John R. (1996). "Ru3(CO)9(μ3-η2,η2,η2-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 Isoxazoline[60]fullerenes".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 [Ir(2-phenylpyridine)2(9-R-4,5-diazafluorene)]+ (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.
![[[Ph3P]2Pt]6(η2-C60)](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aFullerene_4.png)
