Gadolinium Carbide Metallofullerene Gd₂C₂＠C₉₂ And Small Carbon Nanotube C₉₀

This dissertation here provided a systematic review on the progress in types, structure characteristics, synthesis, extraction, isolation and purification of cage shaping fullerene, carbon nanotube, non-carbon inorganic fullerene and endohedral fullerenes. Isomer free purification and single crystal X-ray diffraction studies of functionalized derivatives involved in conventional metallofullerenes and cluster metallofullerenes have been given special emphasis. Trifluoromethyl, chloro and bromide derivatives and organametallic complexes of large empty fullerenes with well determined structures by crystallographic studies, along with those by 19F NMR method were all included.Calculations using quantum chemistry density functuional theory(DFT) on structure optimization, isomer stability order prediction, mutual interactions between endohedral clusters and carbon cages with respect to TNT and carbide cluster fullerenes M3N@C2n (M=Sc,Y,2n=68-98) and M2C2@C2n (2n=60-100) were reviewed in detail. Eight kinds of exohedral functionalization reactions reported in recent years in regard to metallofullerenes, potential applications of fullerene and metallofullerene in chemistry and material field, potential applications of water soluble derivatives of metallofullerene in medical science were comprehensively summarized here.We have also carried out systematic work on arc discharging synthesis, o-dichlorobenzene extraction aided with ultrasonication and multi-step HPLC isolation without using recycling devices for Cd endohedral fullerenes. Complete Gd containing metallofullerene series Gd2C2n (2n=90-106) were obtained, and each individual product has been characterized by LDI-TOF-MS and UV-Vis-NIR spectra, of which Gd2C94(Ⅰ) was successfully grown cocrystalizing with Ni(OEP). X-ray diffraction studies were performed on Gd2C94(Ⅰ)·Ni(OEP) single crystal, and exhaustive calculations have been implemented involving carbide cluster fullerene based on C92 cage.All UV-Vis-NIR spectra of Gd2C2n were made careful comparison with corresponding M2C2n (M=Er or Dy) reported. Those of Gd2C2n (2n=90-94) resemble the relevant ones of M2C2n (M=Er or Dy), indicating both structures may contain the same carbon cage isomer. As with Gd2C2n (2n=96-106), no large endohedral fullerene counterparts were reported, except Gd2C98 and Gd2C100, which distinctly differ from Dy3C98 and Dy2C100 in terms of optical absorption behaviour, respectively.Crystallographical studies of Gd2C94(Ⅰ)·Ni(OEP) single crystal revealed that Gd2C94(Ⅰ) utilized a chiral D3(85)-C92 isomer, present as a pair of entiomers, with Gd2C2 unit encapsulated inside the carbon cage. Each Gd atom resided on either side of fully ordered C2 unit at the cage center, making movements ranging from seven different positions near around. The whole Gd2C2 unit inside the cage looks like a butterfly continuously winding both wings.Quantum chemistry molecular mechanics MM2 field modeling, semiexperience AM1 level simulation, DFT B3LYP/3-21G(d) level calculation was successively adopted to find out (LUMO+2)-(LUMO+1) band gaps of all 86 IPR isomers of C92 neutral cage and those relative energy of 4 negative cage ions. D3(85)-C92 and C1(67)-C92 listed as three most stable candidates for encapsulating M2C2 cluster, which tend to transfer 4 electrons to the fullerene cage, according to the two methods. Thus, the two tentative methods used here hunting for most likely candidates for endohedral fullerenes are reconfirmed accurate and effective. The three most stable candidates determined by 4 anion criteria were utilized to accommodate Gd2C2 unit, Gd2C2@D3(85)-C92 was found the most stable, with a big HOMO-LUMO gap of 1.762 eV.Computations at the B3LYP level with the 3-21G(d) basis were also performed to compare the relative stabilities of the carbide, Gd2C2@C92, and the conventional endohedral, Gd2@C94. C2(121)-C94 recommended as the most stable hexa anion by Popov and Dunch was examined. Gd2@C2(121)-C94 was showed less stable than Gd2C2@D3(85)-C92, while more stable than Gd2C2@C1(67)-C92 in terms of relative energy. Calculations confirmed the high stability of Gd2C2@D3(85)-C92 and suggested Gd2C94(Ⅱ) may be Gd2@C2(121)-C94, which is also consistent with the chromatographic behavior of the two Gd2C94 isomers. Another work involving higher fullerene C90 was presented in this dissertation as well. Detailed procedures of arc discharging synthesis, ultrasonication aided O-dichlorobenzene extraction and multi-stage HPLC isolation without recycling to obtain three isomer pure C90(Ⅰ,Ⅱ,Ⅲ) were provided.C90(Ⅰ,Ⅱ,Ⅲ) were characterized by LDI-TOF MS and UV-Vis-NIR spectra. Absorption peak wavelengths of C90(Ⅱ,Ⅲ) were close to Xu reported C90(Ⅰ,Ⅱ), respectively. As suggested, our C90(Ⅱ) and Xu's C90(Ⅰ) likely uitlized the same carbon cage, so did our C90(Ⅲ)and Xu's C90(Ⅱ). Our C90(Ⅰ) had no counterpart with similar absorption behaviour reported.ALS synchrotron X-ray diffraction measurement on C9o(I)-Ni(OEP) revealed a completely ordered D5h(1)-C90 isomer, a small carbon nanotube, the third member among its C60+10n fullerene nanotube series, which has never been reported either of isolation or characterization. Its structure was fully described compared with that of C60 and C70. The surprising appearance of D5h(1)-C90 may be attributed to doping Sm into graphite rods for arc discharging.To provide direct and graphic insight of the nature of such interaction between the fullerene cage and the metalloporphyrin, computations on the free D5h(1)-C90, free Ni(OEP) and cocrystal structure experimentally determined were performed at B3LYP/6-31G(d), and PBEPBE/DZP level, respectively. Calculation results produced electrostatic potential mapping on the isosurface of individual D5h(1)-C90 and Ni(OEP),showing all hexagons residing on the cage equator with electron deficient property, while N4 region at Ni(OEP) center presenting electron rich characteristics, which drived the two moities forming supermolecular comolexes automatically.Molecular orbitals of HOMO-10 and HOMO-28 showed direct covalent interactions between D5h(1)-C90 and porphyrin via atomic orbital overlapping which were not reported in previous studies. In the case of HOMO-10, nickel selectively bond to the nearest carbon atom from the carbon cage, being consistent with experimetal determintion. In the case of HOMO-28, there exist extraordinary orbital interactions where two pairs of 6:5 bonds of the above mentioned carbon atom interacted with both a C-C bond and a Ni-N bond of one porphyrin at the same time. Thus revealed nature of mutual interation nature between fullerene cage and metal porphyrin.