\rilucs ( N M R . elemental analysis) were used for the determination of the lirst reflection in the X-ray I3Yh. ,~II,FC~II. <,/win. Itrt. Ed. Etrgi. 1993, 32. 1357 powdcr dill'raction patterns.[9] G . Albei-ti. hi. G Bernasconi. M. Casciola. Retrt.t. P / J / w~. 1989. fi. 245. [lo] G. tlonath. K . Kawazoe. J. Chiwi. Eng. Jpn. 1983, 16. 470. [I I ] Stirtiice iirciis \$ere investieated by BET analysis. The presence of mesopores uah cxcluded hy the rcversihil~ty of the adsorption isotherms. Information on the ~o l i i m e uf ihc micropores was derived from both the t-plot and the Horv;irh Kawiime analysis: the samples were previously degassed at lo-' Torr. Crystalline -,-ZrP I was used 21s a nonporous reference material.Based on the superaromaticity concept we predicted that C,, was a soccerball-type Since C,, has been available on a preparative scale,[1h1 one of our big concerns associated with biomimetic studies on enzymes[23 31 has been the molecular recognition of C,,, at active sites in the hydrophobic pocket of enzymes and the resulting biological functions.[41 Very recently such an exciting example was reported for the inhibition of HIV-1 protease by C,, derivatives;['] we were interested in the fundamental problem of how C,, interacts with the cylindrical hydrophobic cavity of y-cyclodextrin (i'-CyD) in the complex formed on recognition of C,, by y-CyD in water. Such ;I host-guest interaction is generally investigated in the equilibrium system in solution. in which, however, other complexes of different compositions can exist. To avoid this problem, the stable inclusion complex of defined composition should be studied. For this reason we have tried to prepare a stable C,,,?;-CyD complex; an unstable complex of nondefined composition has already been reported.[,' The preliminary examination of the complex formation in the two phase solution system (fullerenes in toluene, y-CyD in water) demonstrated that, firstly. among x-, pand ;.-cyclodextrins only y-CyD formed the complex and. secondly, ;.-CyD recognized only C,, in the solution of C,,, and C,,. The latter observation is particularly interesting because. judging froin the cavity size of p C y D (9 8, circular opening) and the size of soccerball C,, (7 8, diameter) and["I Prof.

In all nitrogen-fixation processes known so far--including the industrial Haber-Bosch process, biological fixation by nitrogenase enzymes and previously described homogeneous synthetic systems--the direct transformation of the stable, inert dinitrogen molecule (N2) into ammonia (NH3) relies on the powerful redox properties of metals. Here we show that nitrogen fixation can also be achieved by using a non-metallic buckminsterfullerene (C60) molecule, in the form of a water-soluble C60:gamma-cyclodextrin (1:2) complex, and light under nitrogen at atmospheric pressure. This metal-free system efficiently fixes nitrogen under mild conditions by making use of the redox properties of the fullerene derivative.

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Different from C60 dianion which readily reacts with electrophiles, supramolecular C60 dianion (2) generated from gamma-cyclodextrin-bicapped C60 (1) and NaBH4 (or diborate) in DMSO-H2O (9:1, v/v) is able to reduce N-N+, C=C-EWG and C=O bonds to provide the respective dihydro derivatives; 1-mediated reduction of acetophenone with NaBH4 in the presence of (Me2N)2CH2 and EtONa gives turn over frequency (TOF)/h of 400.