Formation of hydrides of fullerene-C60 and fullerene-C70

Abstract

Fullerene-C6, and fullerene-C,, have been reduced by various methods to di-and tetra-hydro derivatives. Reduction by diimide is the most satisfactory method with regard to both yield and ease of carrying out of the reaction. The 'H NMR chemical shifts are highly solvent dependent, and are ca. 1 ppm further downfield in carbon disulfide than in benzene; the shifts for C60Hn compounds are downfield compared with those for C, , Hn compounds, due possibly to differences in strain between the cages and/or a field effect operating across the cage void. 1,2,3,4-TetrahydrofuIlerene-C, is the main product from reduction of fullerene-C,, with diimide, and all other tetrahydro derivatives that can be produced by addition across the high order bonds appear to be present, together with more highly hydrogenated derivatives. Eight products are obtained on diimide reduction of fullerene-C,,; two have been characterised as 1 ,5,6,9-tetrahydrofullerene-C,, and 1 ,7,8,9-tetrahydrofullerene-C,,, and two others are the 1,9-and 7,8-dihydrofullerenes obtained by reduction with diborane. The other four derivatives may be the other tetrahydro isomers which can be obtained by addition across the 1,9-bond and its other equivalents. The hydrogenated fullerenes are more soluble in carbon disulfide than in either benzene or toluene, thus facilitating observation of the 13C satellites of 1,2dihydrofullerene-60 in the 'H NMR spectrum. The C-H and H-H coupling constants are 141.2 and 15.7 Hz respectively; a 13C-12C isotope shift of -17 ppb is also observed. Coupling constants for interhexagon (6:5) bonds range from 9.3-9.8 Hz, whilst those for interpentagon (6:6) bonds range from 13.9-1 6.3 Hz. The latter are exceptionally large, and the differentiation between the two types should prove a valuable aid in structure determination of hydrogenated fullerenes and derivatives thereof.

Hydrogenation of Fullerene C60: Material Design of Organic Semiconductors by Computation

“…T h e s ei s o m e r sa r en a m e d1-11 in boldface. As predicted by Matsuzawa et al [51] from quantum-chemical calculations, two isomers, 1 from 1,2-addition and 5 from 1,4-addition, have been synthesized [35,39]. Furthermore, isomer 1 has been synthesized by many different methods [52].…”

“…In Figure 5 (b), the second H 2 pair is added to one of the carbon atom pairs labeled 1-8 and these isomers are named 1-8. Experimentally, some of the eight isomers have been synthesized, and four isomers (1, 4, 6,and8)amongthem were identified [36,[39][40][41][55][56][57].…”

“…Hydrogenated fullerenes, C 60 H 2 ,C 60 H 4 ,a n dC 60 H 6 , have been prepared by hydroboration [35,36], hydrozirconation [37], rhodium-catalyzed hydrogenation [38], diimide [39] and hydrazine [40] reduction, dissolving metal reduction [41,42], photoinduced-electron-transfer reduction with 10-methyl-9,10-dihydroacridine [43,44], and ultrasonic irradiation in decahydronaphthalene [45]. In many cases, a mixture of C 60 ,C 60 H 2 ,a n dC 60 H n (n > 2) is obtained [46].…”

Gas phase fullerene anions hydrogenation by methanol followed by IRMPA dehydrogenation

“…Elemental composition determination allows us to identify the different isotopic distributions ( Figures 2B-b [20,50]. In the present conditions, it has to involve either direct abstraction of hydroxyls by the fullerene or the substitution of hydrogen atoms on the fullerene by hydroxyls.…”

“…To our knowledge, the only reported successful hydrogenation of an azafullerene using a mass spectrometer was by Drewello and coworkers [14]. The synthetic approaches reported and leading to the formation of fullerene hydrides include the Birch reduction [11,15,16], the Benkeser reduction [17], polyamine reduction [18,19], reduction by diimides [20], hydroboration [21,22], hydrogen transfer reduction [7,11,23,24], photoreduction [25], transition-metal catalyzed hydrogenation [26 -28], zincconcentrated hydrochloric acid reduction [9,29,30], Zn(Cu) reduction [31][32][33], hydrozirconation [34], hydrogen radical induced hydrogenation [35], electrochemical reduction [36 -38], sonication [39], direct reduction by hydrogen [27, 40 -43], and direct exposure to atomic hydrogen [44,45]. Typically involving extreme conditions, with temperatures of several hundred Kelvin, pressures about several mega Pascal, or condensed phase condition [7,15,21,22,46], they significantly differ from the hydrogenation conditions used here and leading to the addition of up to 11 H…”