Fullerene complexes structure

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. 

The possibility of this binding mode was shown recently with the synthesis and structural analysis of the dumbbell-shaped bis-fullerene complexes of molybdenum and timgsten. The X-ray crystal structure proves the (71 -0 0)21 1 binding mode (Figure 7.9) [87]. 

As far as the fullerene internal structure is concerned, there is little change on metal complexation. The metal bound transannular [6,6] bond is elongated relative to the remaining fullerene C=C bonds. It often attains a length (=1.5 A) comparable with that of other C—C bonds such as the transannular [6,5] bond or those for an analogous alkene complex. The structure often is described as metallacyclopro-... 

NMR spectroscopy has been an extraordinary important technique for structure determination of hydrogenated fullerenes ever since the first synthesis of hydrogenated fullerenes almost two decades ago. During this time, technical advances have pushed the limits regarding both sensitivity and spectral resolution. Also, sophisticated 2D NMR experiments have been implemented more and more frequently in recent years. Consequently, NMR spectroscopy has now been used to successfully characterize complex hydrogenated fullerenes whose structure for a long time... 

Figure 15.30 X-ray crystal structure of a derivative of the endohedral fullerene complex Sc3N C80 (Sc and N atoms shown as large spheres).51...

The X-ray crystal structure of the molecular complex of 9,9 -trans-bis-telluraxanthenyl 25 and fullerene has been reported <1997CPH407>. These types of fullerene complexes act as organic semiconductors (see Section 7.11.8.2). 

Kuzubov A.A., Avramov P.V., Ovchinnikov S.G, Varganov S.A., ToMilin F.N. Electron and atomic structure of isomers of endo- and exoedral fullerene complexes with two lithium atoms. Fiz.Tv.Tela (in Russian) 2001 43 1721-1726. 

A complex, multiply bridged 1,2,3,4-adduct of C60 (168) (Scheme 1.11) including a noninherently chiral addition pattern as well as a multitude of stereogenic centers in the addend moiety was obtained in a tandem reaction between the alkaloid scandine and Ceo-324 The sequence included a photoin-duced addition of the tertiary amine subunit of the alkaloid and a [2 + 2] cycloaddition of its vinyl group to the adjacent intrahexagonal formal double bond of the fullerene. The structural elucidation included 1H-1 H COSY-, HMQC- (heteronuclear multiple quantum coherence), HMBC-, and ROESY-(rotating frame Overhauser enhancement spectroscopy) NMR experiments and... 

The heteroatom cy clopentadienyl analog 1,4,2-P2 SbC2 Bu 2 has been coordinated to Tl(l) via equation (2), producing zigzag polymer (2). Thallium coordination has played an important role in crystallographic characterization of metal-fullerene complexes, providing the first structurally characterized pentahapto metal complexes of Ceo (3) and C70 (4). The key to the formation of these monothallium(l) compounds was the arylation of the fullerenes. Methylated Ceo forms a thallium complex as well. ... 

Structural Proposetls for Endohedral Metal-Fullerene Complexes, Chem. Phys. Lett. 187, 1-7 (1991). 

C60 and Cyo fullerenes are able to form complexes with resorcinarene [80]. In this case, the host molecule can guest only one fullerene molecule in its inclusion complex structure. The n-n, CH-n and n-n interactions were observed by CPMAS and FTIR analysis data. Chattopadyay and coworkers [81] investigated the ability of C o and Cyo fullerenes to form ICs with a series of crown ethers. They showed that fullerenes can form 1 1 molecular complexes with crown ethers, but two of them, dibenzeno-24-crown-8 and dibenzeno-30-crown-10, are able to form complexes only with C6o fullerene, not with Cjq. 

Rubin, Y. Parker, T.C. Kahn S.I. Holliman, C.L. McElvany S.W. Precursors to endohedral metal fullerene complexes synthesis and x-ray structure of a flexible macrocyclic acetylenic cyclophane CgiH h- J. Am. Chem. Soc. 1996, 35(22), 5308-5309. 

The most widely studied porphyrins are 6, R = Et, R = H (OEP), for M = Zn. Ru(CO), Pd, Cu, Ag, Ni. VO, Co. and Fe. with much of the work covered in a recent review article.The complexes fall into two types The first type includes ethyl groups in the. y -form, with the alkyl groups directed toward the fullerene, either one or two porphyrins associated with each fullerene (includes endohedral fullerenes). " and in the latter case, they almost shroud the fullerene. The second type includes four adjacent ethyl groups in either side of the porphyrin plane (anti-form), allowing slipped porphyrin-porphyrin contacts (includes endohedral fullerenes),in structures where fullerene-fullerene contacts prevail. 

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