The stabilization of fused-pentagon fullerene molecules

The isolated pentagon rule (IPR) is now widely accepted as a general rule for determining the stability of all-carbon fullerene cages composed of hexagons and pentagons. Fullerenes that violate this rule have been deemed too reactive to be synthesized. The stabilization of non-IPR endohedral fullerenes depends on charge transfer from the encapsulated metal clusters (endoclusters) to fullerene cages, the electronic properties of empty all-carbon cages, the matching size and geometries of fullerene and endocluster, as well as the strong coordination of the metal ions to fused pentagons. The stability of non-IPR exohedral fullerenes can be rationalized primarily by both the 'strain-relief' and 'local-aromaticity' principles. This Review focuses on recent work on stabilization of non-IPR fullerenes, including theoretical and empirical principles, experimental methods, and molecular structures of fused-pentagon fullerenes characterized so far. The special chemical properties of non-IPR fullerenes that distinguish them from IPR-satisfying ones are also emphasized.NNSFC 20525103,20531050,20721001 973 Program 2007CB81530

C72Cl4: A Pristine Fullerene with Favorable Pentagon-Adjacent Structure

通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R ChinaA long-sought empty non-IPR fullerene, C-#11188(72), which is more stable than the sole IPR isomer in the fullerene[72] family, has been retrieved and crystallographically characterized as (C72Cl4)-C-#11188. Mass spectrometric data support the facile dechlorination of (C72Cl4)-C-#11188 and, in turn, the possible stability of pristine C-#11188(72).NNSF of China 21031004,20721001 ,20525103 973 Program 2007CB815301,2011CB935901 NFFTBS J103041

Capturing the Long-Sought Small-Bandgap Endohedral Fullerene Sc3N@C-82 with Low Kinetic Stability

通讯作者地址: Yang, SFThe long-sought small-bandgap endohedral fullerene Sc3N@C-82 with low kinetic stability has been successfully synthesized and isolated for the first time, for which the molecular structure has been unambiguously determined as Sc3N@C-82-C-2v(39718) by single crystal X-ray diffraction. The C-82-C-2v(39718) (or labeled as C-82-C-2v(9) according to the conventional numbering of the isolated pentagon rule (IPR) isomers based on the Fowler-Monolopoulos spiral algorithm) isomeric cage of Sc3N@C-82 agrees well with its most stable isomer previously predicted by DFT computations and is dramatically different to those of the reported counterparts M3N@C-82-Cs(39663) (M = Gd, Y) based on a non-IPR C-82 isomer, revealing the strong dependence of the cage isomeric structure on the size of the encaged metal for C-82-based metal nitride clusterfullerenes (NCFs).National Natural Science Foundation of China 21132007 2137116 U1205111 National Basic Research Program of China 2011CB921400 973 project 2014CB84560

Carbon arc production of heptagon-containing fullerene[68]

通讯作者地址: Xie, SY (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Xiamen Univ, Fujian Prov Key Lab Theoret & Computat Chem, Xiamen 361005, Peoples R China 4. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected], [email protected], [email protected] carbon heptagon ring is a key unit responsible for structural defects in sp(2)-hybrized carbon allotropes including fullerenes, carbon nanotubes and graphenes, with consequential influences on their mechanical, electronic and magnetic properties. Previous evidence concerning the existence of heptagons in fullerenes has been obtained only in off-line halogenation experiments through top-down detachment of a C(2) unit from a stable fullerene. Here we report a heptagon-incorporating fullerene C(68), tentatively named as heptafullerene[68], which is captured as C(68)Cl(6) from a carbon arc plasma in situ. The occurrence of heptagons in fullerenes is rationalized by heptagon-related strain relief and temperature-dependent stability. (13)C-labelled experiments and mass/energy conservation equation simulations show that heptafullerene[68] grows together with other fullerenes in a bottom-up fashion in the arc zone. This work extends fullerene research into numerous topologically possible, heptagon-incorporating isomers and provides clues to an understanding of the heptagon-involved growth mechanism and heptagon-dependent properties of fullerenes.NNSF of China 21031004 21021061 20973137 20876127 973 Program 2007CB815300(1,7) 2011CB93590

Propagative Exfoliation of High Quality Graphene

通讯作者地址: Deng, SL (通讯作者) Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China. [email protected]; [email protected] quality graphene materials that readily disperse in water or organic solvents are needed to achieve some of the most ambitious applications. However, current synthetic approaches are typically limited by irreversible structural damages, little solubility, or low scalability. Here, we describe a fundamental study of graphene chemistry and covalent functionalization patterns on sp(2) carbon lattices, from which a facile, scalable synthesis of high quality graphene sheets was developed. Graphite materials were efficiently exfoliated by reductive, propagative alkylation. The exfoliated, propagatively alkylated graphene sheets (PAGenes) not only exhibited high solubility in common solvents such as chloroform, water, and N-methyl-pyrrolidone, but also showed electrical conductivity as high as 4.1 X 10(3) S/m, which is 5 orders of magnitude greater than those of graphene oxides. Bright blue photoluminescence, unattainable in graphene, was also observed. We attribute the rise of blue photoluminescence in PAGenes to small on-graphene sp(2) domains created by the propagative covalent chemistry, which may expand from graphene edges or existing defect sites leaving sp(2)-hybridized patches interlaced with sp(3)-hybridized regions. The intact sp(2) domains enable effective electrical percolation among different graphene layers affording the observed high electrical conductivity in PAGene films.National Key Basic Research Program of China 2013CB933901 National Natural Science Foundation of China 21171140 21021061 21031004 U1205111 Natural Science Foundation of Fujian Province of China 2013J01056 Fundamental Research Funds for the Central Universities University of Maryland U.S. National Science Foundation CAREER CHE-105551

Retrieving the Most Prevalent Small Fullerene C(56)

通讯作者地址: Xie, SY (通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] of China,20721001 ,21031004 973 Program 2007CB815301 2011CB93590

Pentagon-Fused Hollow Fullerene in C-78 Family Retrieved by Chlorination

通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Wuhan Univ, Dept Chem, Minist Educ, Key Lab Analyt Chem Biol & Med, Wuhan 430072, Peoples R ChinaC-78 is one of the most widely investigated higher fullerenes. Among its huge isomer family, only one non-IPR (IPR = isolated pentagon ring) cage, the C-2-symmetric C-#22010(78), was previously stabilized by endohedral derivatization. Here we report a new C-1-symmetric non-IPR hollow isomer, C-#23863(78), which was captured as (C78Cl8)-C-#23863 and then subjected to a regioselective substitution reaction with benzyl hydroperoxide to form C-#23863(78)(OOCH2C6H5)Cl-7. The structural connectivity of C-#23863(78), which contains a pair of fused pentagons, was confirmed by single-crystal X-ray diffraction analysis of the C-#23863(78)(OOCH2C6H5)Cl-7 molecule, which shares the same fullerene core with (C78Cl8)-C-#23863, support for the structure is provided by comparable IR measurements and computation. Theoretical studies suggest that the differences in C-Cl bond length, intermediate stability, and steric effects of the involved molecules account for the chemical regioselectivity of the substitution reaction.NNSF of China 20525103,20721001 ,20625516 973 Program 2007CB81530

An Entrant of Smaller Fullerene: C-56 Captured by Chlorines and Aligned in Linear Chains

A smaller fullerene C-56 (#913) is stabilized, isolated, and crystallographically characterized as C56Cl10. The geometric parameters of C56Cl10 imply the otherwise unstable cage of C-56 can be stabilized by chlorination through releasing its surface strains and maintaining fragmental aromaticity. An unexpected C Cl center dot center dot center dot Cl C short contact, as well as the linear alignment with pearl - necklace-shaped, is revealed in C56Cl10 crystal.NSFC,20525103,20531050,20721001,20425312, 20423002 973 Program,2007C13815301

Chlorofullerenes featuring triple sequentially fused pentagons

通讯作者地址: Tan,YZ(通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected], [email protected] triple sequentially fused pentagons (TSFP) motif is one of the basic subunits that could be used for constructing fullerenes, but it violates the isolated pentagon rule (IPR) and has not been found in carbon cages to date. The properties of TSFP-incorporating fullerenes are thus poorly explored both theoretically and experimentally. Reported herein are four chlorinated derivatives of three different fullerene cages, all with the TSFP motif. X-ray crystallographic analyses indicate that the molecular strain inherent to the pentagon adjacency of a TSFP is significantly relieved upon exohedral chlorination, leaving one of the four pentagon fusion sites unsaturated and rendering the present derivatives chiral. This unique reactivity, in stark contrast to that of previously reported non-IPR fullerenes containing double fused pentagons or triple directly fused pentagons, can be rationalized by density functional theory calculations, and are expected to stimulate further studies of these new members of the fullerene family, both theoretically and experimentally.NNSF of China 20525103,20531050,20721001,20423002 20673088 973 Program 2007CB81530