Synthesis,Separation And Characterization Of Novel Hydrofullerenes In Low-pressure Combustion System

Since the discovery of fullerenes,many new kinds of fullerenes have been published,but they are only a small part of the whole field of fullerenes,Moreover,the formation mechanism of fullerene is still a puzzling problem for many years.In recent years,our research group has constantly studied and improved the conditions for synthesis of fullerenes in a low-pressure benzene/oxygen diffusion combustion method.It is found that many kinds of new fullerenes can be stabilized by the way of hydrogen exohedral derivatization.Most importantly,these fullerenes have potential applications in solar cells,optical materials,superconducting materials,polymer materials and catalysis et al.Therefore,it is of great significance to obtain more novel fullerene structures in the low-pressure combustion system,both for the development and application of new fullerenes and for the study of the formation mechanism of fullerenes.In this paper,we have extracted and isolated products synthesized in a low-pressure benzene/oxygen diffusion combustion method,and obtains some special new fullerenes which are difficult to obtain in other synthesis of fullerene methods.The structures were characterized by X-ray single crystal diffraction.Moreover,in this paper,some new hydrogenated non-IPR fullerenes in a low-pressure benzene/oxygen diffusion combustion system have high reactive activity,and it is difficult to obtain high quality single crystal.For the first time,we used decapyrrylcorannulene molecule synthesized by organic synthesis methods to carry out supramolecular self-assembly wyith unstabled hydrofullerenes.The disorder of atoms on fullerene carbon cages can be restricted by the formation of weak ?-? interactions between decapyrrylcorannulene and fullerenes during crystallization.Therefore,some eutectic structures which are difficult to cultivate single crystals have been obtained,which solved the problem of difficult to cultivation of single crystals in the hydrocarbon system.The main contents and innovations of this paper include the following aspects:?.Three kinds of non IPR fullerenes,#271C50H10,#369C54H12 and#1911C64H4,were characterized by X-ray single crystal diffraction for the first time.Their single crystal structures shows that the structure of#369C54H12 and#1911C64H4 are very similar,both of them with triple adjacent fused pentagons,and the special triple fused pentagons is made up of a trigonometric shaped C4 unit.Very interestingly,the transition from#271C5OH10 to#369C54H12 and C60 to#1911C64H4 can be achieved directly through the very simple trigonometric shaped C4 unit insertion.Inspired by their transformation process of crystal structures,we proposed the C4 insertion mechanism for the first time.Moreover,the identification of these three new structures is the most direct evidence of C4 insertion growth mechanism of fullerenes.The introduction of the C4 insertion mechanism has made up for the previous vacancy on the mechanism of C2 insertion,which can explain the unexplained phenomenon of the C2 insertion growth mechanism and provide very powerful experimental evidence for the study of the "bottom-up"growth mechanism of fullerenes.?.A special non-IPR fullerene C66H4 containing two heptagons accompany with two fused pentagons pairs was captured in a low-pressure benzene/oxygen diffusion combustion system for the first time,and the crystal structure was successfully characterized by X-ray single crystal diffraction.In addition,we have also carried out a series of characterization of the two heptagon-containing non-IPR fullerene C66H4,and found that C66H4 have unique C-H vibrations in infrared and Raman spectrum,as well as special electrochemical properties.Moreover,the theoretical calculation shows that the hydrogenation process is the most important factor that dihepta-C66H4 can be stabilized and successfully captured.The discovery and characterization of the dihepta-C66H4 structure is of great significance for the study of the new fullerene structures and the formation mechanism of heptagon-containing non-IPR fullerenes in the low-pressure benzene/oxygen diffusion combustion system.?.Two kinds of non-IPR fullerenes#1205C58H12(CH2)and#1911C64H4(CH2),which capture Carbene free radicals,were first isolated from the low-pressure benzene/oxygen diffusion combustion system for the first time.we have obtained high quality single crystals through supramolecular self-assembly of decapyrrylcorannulene and the two kinds of unstabled hydrofullerenes,and the crystal structures were successfully characterized by X-ray single crystal diffraction.The successfully synthesis and characterization of the two structures indicate that there are many Carbene free radicals in a low-pressure benzene/oxygen diffusion combustion system.Moreover,these active CH2 radicals carry out additional reactions near the adjacent fused pentagons on non-IPR C58 and C64 carbon cages,indicating high reactive activity on the site near the fused pentagons of fullerenes.The successfully characterization of the two structures provides a very important experimental and theoretical basis for the study of the chemical reaction and functionalization of non IPR fullerenes,as well as the study of the formation mechanism of fullerenes in the low-pressure benzene/oxygen diffusion combustion system.?.Two non-IPR fullerene C60 isomers#1809C60H8 and#1809C60H10 were isolated and purified from the low-pressure benzene/oxygen diffusion combustion system.We have obtained high quality single crystals through supramolecular self-assembly of decapyrrylcorannulene and the two kinds of unstabled C60 isomers,and the crystal structures were successfully characterized by X-ray single crystal diffraction for the first time.The structure of#1809C60H8 and#1909C60H10 shows that they have the same parent cage with Cs-#1809C60Cl8 as previously published by our group,which are hydrogenated by 8 hydrogen atoms on the#1809C60 carbon cage to form#1809C60H8 and hydrogenated 10 hydrogen to form#1809C60H10.Compared with#1809C60H8,#1809C60H10 adds one hydrogen to adjacent fused pentagons and one hydrogen to the site near adjacent fused pentagon.It is indicated that non-IPR C60 isomers with adjacent fused pentagons have very active sites on the carbon cages and can be continuously hydrogenated.Therefore,it is expected that more hydrogenated C60 isomers should be synthesized in the low-pressure benzene/oxygen diffusion combustion system,which provides a very reliable experimental basis for obtaining more fullerene isomers.?.Three types of C71H2 isomers of Carbene free radical were isolated from the low-pressure benzene/oxygen diffusion combustion system.we have obtained high quality single crystals through supramolecular self-assembly of decapyrrylcorannulene with three kinds of C71H2 isomers,and the crystal structures C71H2-?,C7-H2-?,C71H2-? were successfully characterized by X-ray single crystal diffraction for the first time.It is shown that the high activity of Carbene radicals carry out additional reaction on different active sites of C70.Moreover,C71H2-? isomers have been synthesized and the unique C71H2 isomer they have obtained in arc discharge system published before.Although they have made relevant characterization and theoretical calculation,they have not shown the definite single crystal structure of C71H2-?.In the low-pressure benzene/oxygen diffusion combustion system,we have successfully identified three kinds of C71H2 isomers,which indicate that the species of fullerenes is more diverse in the combustion system than the traditional arc discharge.It also indicates that there are many Carbene radicals in the high temperature environment of the low-pressure benzene/oxygen diffusion combustion system,which can be inferred that the highly active Carbene radicals play a very important role in the growth of fullerenes.The characterization of these three kinds of fullerenes is of great significance in subsequently functional modification and growth mechanism of fullerenes.The successfully synthesis and characterization of a series of novel fullerenes show that the low-pressure benzene/oxygen diffusion combustion is a very effective method to multitudinous synthesis of novel fullerenes.The determination and characterization of these structures provide rich experience for obtaining more novel fullerenes in the future,and more importantly,it provides a very reliable experimental basis for the study of the growth mechanism of fullerenes in the low-pressure benzene/oxygen diffusion combustion system.