Fullerene complexes reactions

The most recent report of -coordination to a ruthenium porphyrin fragment details the reaction of [Ru(OEP)j2 with C o in benzene/THF (100 1) solution. The UV-visible spectrum of the complex showed a new band at 780 nm, not observed in the spectrum of either Ru(OEP) 2 or C(,o, and H and C NMR data also indicated the presence of a new complex. This has been formulated on the basis of the spectroscopic data as the fullerene complex Ru(OEP)(... 

Fullerene The reaction of 1 with an equimolar amount of fullerene- 60 in toluene at room temperature gives the first fullerene complex of titanium Cp2Ti(q2-C60) 121 [60]. An X-ray diffraction study of this complex has shown that it has the structure of a titanacyclopro-pane derivative, which should have a high potential for further derivatization of the fullerene. 

Unlike zirconium, the group IV metal titanium does not form the hydrometalation product but rather a (r -C5Q)-complex. The first titanium-fullerene complex 1 was prepared by reaction of the bis(trimethylsilyl)-acetylene complex of titanocene with equimolar amounts of Cjq (Scheme 7.1). 

Exohedral metal complexes [C6qM]+ are formed by the reaction of Ceo with naked M+ ions (M = Fe, Co, Ni, Cu, Rh, La). ForNi+ the bis-fullerene complex [(C6o)2Ni]+ was also observed. In contrast to the endohedral fullerenes, excitation of these complexes results in facile metal elimination with no associated cage fragmentation. 

Recent additions to the family of alkene complexes are fullerene derivatives such as Rh(CO)(q -Cgo)(H)(PPh3)2 Pd(q -Cgo)(PPh3)2 (Figure 23.17b) and (q -Cp)2Ti(q2-Cgo). The Cgo cage (see Section 13.4) functions as a polyene with localized C=C bonds, and in Cgo Pt(PEt3)2 6, six C=C bonds (remote from one another) in the Cgo cage have undergone addition. Reaction 23.73 illustrates CgQ-for-ethene substitution (the 16-electron centre is retained), and reaction 23.74 shows addition to Vaska s compound (a 16- to 18-electron conversion). Equation 23.75 shows the formation of the first fullerene complex of titanium, by fullerene displacement of a coordinated alkyne. 

Ground state and C70 also react readily with a tertiary aliphatic amine triethylamine (TEA) at high TEA concentrations [87]. The reaction of Cgg and TEA results in the formation of a new absorption band in the blue region, which was initially mistaken as the absorption of a Cgg-TEA charge transfer complex [85,87]. The reaction products appear to be complicated as well, whose separations and identifications remain to be completed. In the photoexcited states of fullerenes, however, reactions with TEA are more efficient even at low TEA concentrations [66,71,118]. The reaction mixture can be divided into two fractions in terms of the solubility in toluene. The relative quantities of the two fractions are somewhat dependent on irradiation time. 

Several reports on the chemistry of endohedral lanthanide fullerene complexes indicate that they are quite similar in reactivity to the empty fullerenes. However, their redox chemistry is very rich since they can also get easily oxidized in contrast to Cgo and C70 [13b,24]. Reactions with a disiUrane [cyclo-... 

Addition reactions, electron transfer reactions, and reactions involving the opening of the fullerene cage (chemical surgery) have been thoroughly studied on fullerenes. Other reactions such as nucleophilic additions, cycloaddition reactions, free-radical additions, halogenations, hydroxylation, redox reactions, and metal transition complexations have been reported for Cgo as well. Furthermore, fullerenes are easily reduced by electron-rich chemical reagents as well as electrochemically. Their oxidation, however, is considerably more difficult to achieve [17]. Thus, electrochemical measurements showed the formation from the monoanion to the hexaanion [18]. 

Similar reaction channels are possible for PI but there are no scattered electrons and dissociative attachment is only possible for El. Different and more complex reactions may occur when more complex targets are involved, i.e. polyatomic molecules or clusters (even including multiple electron collisions and subsequent reactions within the molecular target). Clusters and fullerenes have also been demonstrated to undergo a process of delayed ionization which is akin to thermionic emission in bulk material. 

This review covers all organometallic complexes of Sc, Y and the lanthanides reported in the year 2000 and their reactions. Endohedral fullerene complexes of the lanthanides have, as usual, been excluded. Highlights this year include striking reports of lanthanides in non-classical oxidation states (Sections 3.2 and 5), a remarkable reversible dinitrogen activation described in Section 3.9.2 and evidence for the existence of the divalent hydrides LnH2(THF)2 (Ln = Sm, Yb) (Section 3.10). In addition Evans has assessed the utility of electrospray mass spectrometry for the characterization of organolathanides. The results are promising and the spectra and dissociation patterns show sensitivity to the metal and its oxidation state. ... 

Diederich F, Jonas U, Gramlich V, Herrmann A, Ringsdorf H and Thilgen C 1993 Synthesis of a fullerene derivative of benzo[18]crown-6 by Diels-Alder reaction complexation ability, amphiphilic properties, and x-ray crystal structure of a dimethoxy-1,9-(methano[1, 2]benzomethano)fullerene[60] benzene clathrate Helv. Chim. Acta 76 2445-53... 

Diels-Alder reaction of fullerenes with complex dienes type 52 (Figure 2.6) which have a 2,3-bis-(methylene) bicyclo[2.2.2]octane unit [49]. 

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