T. J. S. Dennis

• B.Sc., M.Sc., D.Phil.
• Professor at Xi’an Jiaotong-Liverpool University

Higher adducts of a fullerene, such as the bis-adduct of PCBM (bis-PCBM), can be used to achieve shallower molecular orbital energy levels than, for example, PCBM or C60. Substituting the bis-adduct for the parent fullerene is useful to increase the open-circuit voltage of organic solar cells or achieve better energy alignment as electron transport...

Environmental stability remains a major challenge for the commercialisation of organic solar cells and degradation pathways remain poorly understood. Designing materials for improved device stability requires an understanding of the relationship between the properties of the donor or acceptor molecule and different degradation mechanisms. Here we s...

With the aim of determining the best input geometry for DFT calculations of [60]PCBM, the geometry of 24 chemically possible [60]PCBM conformers were optimised and their electronic energies and average bond strains were determined. A DFT analysis of the relevant dihedral angles provided insights into the dynamical behaviour of the ester group throu...

Solubilized fullerene derivatives have revolutionized the development of organic photovoltaic devices, but the isomeric complexity that arises from addition of the solubilizing group is often ignored. In article number 2004115, Matthew J. Fuchter and co‐workers separate 10 pairs of enantiomers from the 19 structural isomers of a common fullerene ac...

Solubilized fullerene derivatives have revolutionized the development of organic photovoltaic devices, acting as excellent electron acceptors. The addition of solubilizing addends to the fullerene cage results in a large number of isomers, which are generally employed as isomeric mixtures. Moreover, a significant number of these isomers are chiral,...

High-resolution (600 MHz) 1 H and 13 C chemical shift and 2D HETCOR NMR spectra of [60]PCBM were recorded. Resonances from every carbon atom of the ester, phenyl and cyclo-fullerenyl groups, were fully accounted. Assignments of the fullerene cyclopropa-ring, and all phenyl and ester carbons to their respective resonances were based on a HETCOR 2D N...

The 1H NMR spectrum of phenyl C61 butyric acid methyl ester ([60]PCBM) was recorded at high resolution (600 MHz). All of the 1H resonances expected of the C s -symmetric molecule were observed. The spin-spin couplings in the 1H NMR spectrum were not as expected at first order. Instead, the effects of AA'BB'-type second-order couplings were clearly...

p>Solubilized fullerene derivatives have revolutionised the development of organic photovoltaic devices, acting as excellent electron acceptors. The addition of solubilizing addends to the fullerene cage results in a large number of isomers, which are generally employed as isomeric mixtures. Moreover, a significant number of these isomers are chira...

A number of recent studies have shown that the non-radiative voltage losses in organic solar cells can be suppressed in systems with low energetic offsets between donor and acceptor molecular states, but the physical reasons underpinning this remain unclear. Here, we present a systematic study of 18 different donor:acceptor blends to determine the...

In recent times, as a result of its exceptional resistance to moisture and heat, cesium lead bromide (CsPbBr3) was established as a potential high-performance perovskite material for optoelectronics, which is inclusive of photodetectors and photovoltaics. It has been demonstrated that perovskite single crystal has major benefits over its thin-film...

Organic semiconducting single crystals are ideal building blocks for organic field-effect transistors (OFETs) and organic photodetectors (OPDs) because they can potentially exhibit the best charge transport and photoelectric properties in organic materials. Nevertheless, it is usual for single-crystal OFETs to be built from one kind of organic mate...

Solution-processed organic single-crystalline donor–acceptor heterojunctions (SCHJs) composed of N,N,N′,N′-tetraphenylbenzidine (TPB) and phenyl- C61-butyric acid methyl ester ([60]PCBM) are successfully obtained, and fundamental studies on its charge transport properties are demonstrated, revealing the advantages of applying SCHJs in photovoltaic...

We report the charge transport mechanism, long-term stability and UV-Visible-NIR photo-responsivity of single crystals of [60]PCBM (phenyl-C61-butyric acid methyl ester) - the dominant acceptor material in organic photovoltaics. Despite [60]PCBM's paramount role in such device, its intrinsic properties was largely unknown because of highly disorder...

The molecular structures of 19 purified isomers of bis-phenyl-C 62 -butyric acid methyl ester (“bis[60]PCBM”) were identified by a combination of ¹³ C NMR and UV-Vis absorption spectroscopy, and HPLC retention time analysis. The ¹³ C NMR spectra indicated the symmetry of each isomer. It also showed that all 19 isomers are dicyclopropa-fullerenes (n...

All 19 expected cyclopropa-fullerene isomers of the organic photovoltaic electron acceptor material bis-phenyl-C 62 -butyric acid methyl ester ("bisPCBM") have been isolated from the as-produced isomer mixture by peak-recycling high pressure liquid chromatography to a purity exceeding 99.5%, and their frontier orbitals characterised by UV-Vis absor...

There are only a few reported methods by which the size and morphology of organic single crystals for high-performance organic field-effect transistors (OFETs) or other devices can be controlled. Here, a facile solution-processed antisolvent vapor diffusion method was employed to grow millimeter-length C60 single crystal microwires directly in the...

The molecular structures of 19 purified isomers of bis-phenyl-C62-butyric acid methyl ester (“bis[60]PCBM”) were identified by a combination of ¹³C NMR and UV-Vis absorption spectroscopy, and HPLC retention time analysis. All 19 isomers are dicyclopropa-fullerenes (none are homo-fullerenes). There were 7 isomers with C1 molecular point group symmet...

The as-produced isomer mixture of the organic photovoltaic acceptor material bisPCBM has recently been purified into 19 components by peak-recycling HPLC and their frontier orbitals have been characterised by UV-Vis absorption spectroscopy and cyclic voltammetry. OPV devices based on the purified isomers may now be made, but before meaningful concl...

The as-produced isomer mixture of the organic photovoltaic device acceptor material bis-[60]PCBM has been purified into its constituents by peak-recycling HPLC, and those individual isomers were characterised by UV-Vis absorption spectroscopy and cyclic voltammetry. A total of 19 isomers (from a potential total of 21isomers) were purified from the...

A fullerene derivative (α-bis-PCBM) is purifed from an as-produced bis-phenylC61-butyric acid methyl ester (bis-[60]PCBM) isomer mixture by preparative peak-recycling, high-performance liquid chromatography, and is employed as a templating agent for solution processing of metal halide perovskite flms via an antisolvent method. The resulting α-bis-P...

The as-produced isomer mixture of the organic photovoltaic device acceptor material bis-[60]PCBM has been purified into its constituents by peak-recycling HPLC, and those individual isomers were characterised by UV-Vis absorption spectroscopy and cyclic voltammetry. A total of 18 isomers were purified from the mixture to a standard exceeding 99.5%...

A simple wet chemical method involving only sonication in aqueous GdCl3 solution was used for surface functionalization of iron-filled multiwalled carbon nanotubes with gadolinium. Functional groups on the sidewalls produced by the sonication provide active nucleation sites for the loading of Gd3+ ions. Characterization by EPR, EELS, and HRTEM conf...

Angular-resolved photoelectron spectroscopy using wavelength-tuneable femtosecond laser pulses is presented for a series of fullerenes, namely, C70, C82, and Sc3N[commercial at]C80. The photoelectron kinetic energy distributions for the three molecules show typical thermal electron spectra with a superimposed peak structure that is the result of on...

Structural, electronic, and vibrational properties of the endohedral fullerene Ce@C82 on Cu(111) have been studied by scanning tunneling microscopy (STM) and density functional theory (DFT). Ce@C82 forms islands on the substrate. Our STM measurements show relatively large differences in morphology and electron spectra of molecules within these isla...

Inelastic electron tunneling spectroscopy of Ce-2@C-80 dimetallofullerenes reveals a low-energy inelastic excitation that is interpreted using ab initio calculations and associated with the movements of encapsulated Ce atoms inside the C-80 cage. The electron-vibration interaction in Ce-2@C-80 is unusually high, inducing a pronounced zero-bias anom...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

(Figure Presented) At long last, the elusive thermodynamically most stable isomer of C71,H2 (see structure) has been synthesized through the addition of CH2 across an equatorial bond Of C 70: a site at which sucha reaction is not kinetically favorable. Theoretical studies revealed that the pyrogenic synthetic method used enables reactants to overco...

We use scanning tunneling microscopy to establish controlled contacts to single molecules of endohedrally doped Ce(2)@C(80) fullerenes with C(60) as a reference. The stability of the experimental setup allows for the determination of the conductance of Ce(2)@C(80) relative to the conductance of C(60). The endohedral doping reduces the conductance o...

We show that monolayer-high islands of C60 and C60O can be transferred from Langmuir films on a water or phenol sub-phase to oxide-terminated Si(111) substrates. Faceted islands, in some cases incorporating a foam-like morphology reminscent of that previously observed for Langmuir films at the water–air interface using Brewster angle microscopy, ar...

The electron spin g- and hyperfine tensors of the endohedral metallofullerene Sc@C82 are anisotropic. Using electron spin resonance (ESR) and density functional theory (DFT), we can relate their principal axes to the coordinate frame of the molecule, finding that the g-tensor is not axially symmetric. The Sc bond with the cage is partly covalent an...

A new magnetic resonance imaging contrast agent containing organophosphonate functional groups was synthesized in high yield by a simple synthesis procedure. This molecule exhibits much higher longitudinal water proton relaxivity (37.0 mM(-1) s(-1)) than commercial Omniscan (Gd-DTPA BMA, 5.7 mM(-1) s(-1)) at 0.35 T. Notably, the relaxivity is large...

Photophysical properties of C84 isomers have been measured separately and compared. Intrinsic triplet state lifetimes at room temperature are found to differ dramatically: 4.5 μs for the D2d(II) isomer, 125 μs for Cs(a), and 640 μs for D2(IV). The triplet lifetime of D2(IV) C84 represents the second longest found to date among fullerenes. Measureme...

Two types of the metallofullerene Nd@C82 have been isolated and characterized. HPLC was used to isolate Nd@C82(I, II). The two isomers were characterized by mass spectrometry and UV-Vis- NIR absorption spectroscopy. Nd@C82(I) was found to be similar in structure to the main isomer of other lanthanofullerenes such as La@C82. We assign Nd@C82(I) to h...

Two different structural isomers of Nd@C82 have been isolated using two-stage high-performance liquid chromatography. Their molecular orbital structures have been studied by a combination of scanning tunneling microscopy (STM) and density functional theory (DFT). Matching filled and empty-states STM images to DFT calculations allowed us to distingu...

The electron spin g- and hyperfine tensors of the endohedral metallofullerene Sc@C82 are anisotropic. Using electron spin resonance (ESR) and density functional theory (DFT), we can relate their principal axes to the coordinate frame of the molecule, finding that the g-tensor is not axially symmetric. The Sc bond with the cage is partly covalent an...

For the first time, two types of the metallofullerene NdatC82 have been isolated and characterized. HPLC was used to isolate NdatC82(I, II). The two isomers were characterized by mass spectrometry and UV-Vis-NIR absorption spectroscopy. NdatC82(I) was found to be similar in structure to the main isomer of other lanthanofullerenes such as LaatC82, a...

We have investigated the growth of molecular clusters in confined geometries defined by a bimolecular supramolecular network. This framework provides a regular array of identical nanoscale traps in which further deposited molecules nucleate cluster growth. For the higher fullerene, C84, molecules aggregate into close packed assemblies with an orien...

The interaction of Ce@C82 with clean and silver-terminated Si(111) surfaces has been studied with synchrotron-radiation photoemission spectroscopy and near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy. Use of an Ag/Si(111)-(3×3)R30° surface as an initial substrate enables the molecule-substrate interaction to be progressively strength...

The adsorption behaviour and electronic properties of Ce@C82 molecules on the Ag:Si(1 1 1)-(√3 × √3)R30° surface have been studied using scanning tunnelling microscopy and photoelectron spectroscopy. Submonolayer coverages and multilayer films of Ce@C82 comprise highly ordered molecular domains which have a single, well-defined orientation with res...

A clear understanding of the interactions between the building blocks of self-assembled molecular materials is essential for rational design of functional nanostructures. Intermolecular interactions have been investigated for three different classes of fullerenes in single-walled carbon nanotubes (SWNTs); van der Waals molecule – molecule and molec...

Local magnetic properties of rare-earth (RE) atoms encapsulated in fullerenes have been characterized using x-ray magnetic circular dichroism and x-ray absorption spectroscopy (XAS). The orbital and spin contributions of the magnetic moment have been determined through sum rules and theoretical model calculations, and have been found to be highly r...

Rock and Roll: Endohedrale Fullerene Ce@C82 im Innern einwandiger Kohlenstoffnanoröhren (SWNTs) wechselwirken durch elektrostatische Kräfte und zeigen ein ungewöhnliches dynamisches Verhalten. Translatorische Oszillationen und diskontinuierliche Molekülrotationen wurden (durch hochauflösende Transmissionselektronenmikroskopie) erstmals bei molekula...

We report the purification of the nitrogen-containing incar-fullerenes iNC(60) and iNC(70), and their characterisation by UV-Vis absorption spectroscopy.

We report the purification of the nitrogen-containing incarfullerenes iNC(60) and iNC(70), and their characterisation by UV-Vis absorption spectroscopy.

Carbon nanotubes can encapsulate several molecular species forming one‐dimensional crystals. Using previously reported methods we produced directly‐bonded, asymmetric C60‐C70 dimers and oxygen‐bridged dimers of the type C60‐O‐C60. We present here microscopic evidence of filling single‐walled carbon nanotubes (SWNTs) with the above fullerene dimers...

A comparison of normal incidence X-ray standing wave (NIXSW) spectra from bulk films and monolayers of Ce@C82 on Ag(111) clearly shows that the Ce atom does not adopt a preferred intramolecular bonding site as a result of adsorption. NIXSW profiles measured at room temperature and 100 K are each associated with a coherent fraction of zero, indicati...

Synchrotron-based photoelectron spectroscopy (PES) has been used to investigate the interaction of atomic gold and silver with a covalently bound C60-monolayer adsorbed on Si(111)7×7. In contrast to the relatively benign interaction of silver with the C60/Si(111)7×7 surface, core-level photoemission data reveal a strong interaction of gold with the...

We report the spectroscopic work of two Ce-containing incar-fullerenes, iCeC82 and iCe2C80. UV/Vis, IR, Raman, TOF-MALDI and 13C NMR were employed to investigate the structural and electronic information of these two major isomers of Ce incar-fullerenes. Tumbling motion of two Ce atoms inside the Ih-C80 cage was confirmed and analysed by temperatur...

Most experts agree that it is too early to say how quantum computers will eventually be built, and several nanoscale solid-state schemes are being implemented in a range of materials. Nanofabricated quantum dots can be made in designer configurations, with established technology for controlling interactions and for reading out results. Epitaxial qu...

The adsorption of the endohedral fullerene, La@C82, and the higher fullerene, C84, on Si(100)-2×1 is investigated using a scanning tunneling microscope (STM) operating in ultrahigh vacuum. Both molecules are found to adsorb directly above the dimer rows that are formed on the Si(100)-2×1 surface, as well as in trough sites midway between dimer rows...

The structural properties of solid C84 (mixture of two isomers, D2(IV) and D2d(II) in a 2:1 abundance ratio) were studied by synchrotron X-ray powder diffraction at ambient temperature and elevated pressures. The structure remains strictly cubic to 9.2GPa with no evidence of a structural phase transition, analogous to those encountered in C60 and C...

The pressure behavior of the intramolecular phonon modes of the fullerene C84 and its structural stability have been studied for the first time by means of Raman spectroscopy and synchrotron X-ray diffraction at high pressure up to ∼10 GPa. The volume of the cubic unit cell has been measured as a function of pressure. The experimental data fitted b...

The adsorption of the higher endohedral and empty fullerenes La@C82 and C84 on Ag/Si(111)-(√3×√3)R30° has been investigated using ultrahigh-vacuum scanning tunneling microscopy. At low coverage these molecules form single-layer islands with orientational order, a consequence of the commensurability between the intermolecular separation for each spe...

Face-centered cubic phases of both the D2 and D2d isomers of the C84 anion with band fillings close to those of the A3C60 superconductors are prepared by a two-step reaction involving saturated K8+xC84 phases as intermediates. Rietveld refinement shows that the structures are more disordered than those of K8+xC84, with incomplete occupancy of multi...

The electrochemical and electron spin resonance (ESR) fingerprints of six isomers of C84 [D2(IV), D2d(II), D2d(I), D2(II), C2(IV), and Cs(b)] are presented together with density functional theory (DFT) calculations of the molecular orbitals (MO) energy levels for a total of 10 isomers (D2(IV), D2d(II), D2d(I), D2(II), Cs(V), and C2(I) to C2(V)). Co...

Ultraviolet photoelectron spectra (UPS) of two Ca@C82 isomers (III and IV) were measured with a synchrotron radiation light source. The photoelectron onset energies of isomers III and IV were 0.7 and 0.8 eV below the Fermi level, respectively, which indicates their semiconductive nature. When the excitation energy is tuned, spectral intensity chang...

Raman scattering of D2d-Sc2atC84 and D2d-Y2atC84 is compared to the response of C60, empty D2d-C84, and YatC82. By a detailed analysis of the metal-cage vibrations we found that the unit cell of D2d-Y2atC84 contains at least 2 molecules. No decoupling of the yttrium ions from the C84 cage was observed up to 550 K. The vibrational line widths are go...

The structures of three structural isomers of Sc2@C84(I, II, III) have been determined by 13C NMR and have Cs, C2v, and D2d point group symmetry, respectively. By IR measurements, we have determined that the peaks below 110 cm-1 originate from the scandium-cage vibrational modes based on temperature-dependent IR experiments. Line broadenings of the...

We present the first vibrational study of isomers of the same fullerene; C84{D2(IV)} and C84{D2d(II)}. Owing to their lower symmetry, the spectra of these isomers exhibit many more lines than the previously studied fullerenes C60, C70, and C76. The temperature dependence of the IR spectra indicates a structural phase change occurs, for both isomers...

Raman scattering and infrared absorption is reported for various empty and filled fullerene isomers in the low-energy range below 600 cm⁻¹ to clarify the influence of different carbon cage structures on the bonding strength between encapsulated metal ion and fullerene cage and to check the potential of vibrational spectroscopy for isomer identifica...

Raman scattering and infrared absorption is reported for various empty and filled fullerene isomers in the low-energy range below 600cm−1 to clarify the influence of different carbon cage structures on the bonding strength between encapsulated metal ion and fullerene cage and to check the potential of vibrational spectroscopy for isomer identificat...

The addition of photochemically generated phosphoryl radicals [˙P(O)(OPri)2] to [76]fullerene has been studied by EPR and seven out of the nineteen possible RC76˙ regioisomers are obtained, six of which are stable. This compares with the previously observed addition of phosphoryl radicals to [70]fullerene which afforded three of the five expected R...

The isolation of minor isomers of [84]fullerene (C84), five in total, and their characterization by 13C NMR spectroscopy, have been reported for the first time. The vis-near-infrared absorption spectra for these isomers are also reported. The 13C NMR results indicate that the isolated C84 isomers have, in order of decreasing abundance, C2, Cs(a), C...

Raman scattering and infrared absorption of the C84 and Sc2C84 isomers 23:D2d were studied at room temperature and 95 K. The results are compared to the response of pristine and doped C60. According to the lower symmetry and the higher number of atoms C84 exhibits much more vibrational modes than C60, in particular at wave numbers above 500 cm−1. F...

The isolation of minor isomers of [84]fullerene (C84), five in total, and their characterization by 13C NMR spectroscopy, have been reported for the first time. The vis−near-infrared absorption spectra for these isomers are also reported. The 13C NMR results indicate that the isolated C84 isomers have, in order of decreasing abundance, C2, Cs(a), C...

We present IR and Raman measurements of endohedral compounds Sc2@C84 with D2d symmetry and its empty counterpart C84. Our main task was to determine mutual carbon cage−Sc vibrations. The attention was therefore concentrated in the region below 300 cm−1 in which one expects this type of motions. Comparing spectra for empty and filled isomers with D2...

We report the isolation of nine isomers of [84]fullerene (C84). Of these minor isomers, six were sufficiently abundant to allow characterization by 13C NMR spectroscopy. These have, in order of decreasing abundance, D2(IV), D2d(II), Cs(V), D2d(I), D2(II), and C2(IV) molecular point group symmetry. © 1999 American Institute of Physics.

The room temperature Raman spectra of the C84 isomers 22: D2 and 23: D2d are shown to resemble a downshifted and split C60 spectrum in the range of the radial cage modes below 450 cm-1. Additional Raman lines with a basically similar structure were found for three isomers of Sc2atC84 (Cs, C2v and D2d) below 200 and at 260 cm-1 and attributed to (Sc...

Contrary to nitrogen and phosphorous, atomic hydrogen is not stable in C60 at room temperature. However, recently it was reported that hydrogen can be stabilized the a cube-like cage of Si8O12. In the present experiment the endohedral system HatSi8O12Et8 (Et=ethyl) was produced by ion implantation using ion implantation on a growing Si8O12-film.

The first successful separation and isolation from arc-burned soot of Gd-doped composite rods of a mixture (in an abundance ratio of 3:2) of two minor isomers of C84 with molecular symmetry D6h and D3d, and their characterisation by 13C NMR and UV-VIS-NIR absorption spectroscopy, are described.

High-resolution synchrotron X-ray powder diffraction is used to study the crystal structure of the higher fullerene C-84 in the temperature range 5-295 K. Solid C-84 (mixture of two molecular isomers, D-2(IV) and D-2d(II) in the ratio 2:1, respectively) adopts a face-centered-cubic (fcc) structure at all temperatures (a = 15.817(4) Angstrom at 20 K...

Reaction of solids of pure D2d and D2 C84, as well as mixtures of these isomers, with an excess of potassium produces the cubic phases K8+xC84, with multiple occupancy of the octahedral site by potassium. Analysis of X-ray powder diffraction data reveals that the anions adopt well-defined orientations in the solid, driven by the anion−cation contac...

We report the first production and isolation of mono-incar-fullerenes based on the missing fullerene C80, and their characterisation by UV–VIS–NIR absorption spectroscopy.

Structural and electronic properties of group-2 metal-containing endohedral metallofullerenes (Ca/Sr/ Ba@C-80, Ca/Sr/Ba@C-82, Ca/Sr/Ba@C-84) are investigated for the first time by UV-Vis-NIR absorption spectroscopy and high-resolution C-13 NMR. Direct evidence of the endohedral nature and cage structures are revealed by these measurements. Furtherm...

We report the first successful separation of the two major isomers of C84, i.e. [84-D2]fullerene and [84-D2d(II)]- fullerene, and 13C NMR and UV–VIS–near IR absorption spectra of the purified materials.

The standard molar enthalpy of formation of C70 in the crystalline state at 298.15 K has been determined as 2577.8 ± 16.2 kj mol-1 by microcombustion calorimetry.DeltafHmo(C70, g) at 298.15 K was also derived, using literature data for the enthalpy of sublimation, vapour pressure, solid state heat capacity and solid state entropy, in conjunction wi...

We report the first isolation of strontium- and barium-based metallofullerenes and their characterisation by UV-vis-NIR absorption spectroscopy. The absorption spectra of the present samples (Sr/Ba@C82 and Sr/Ba@C84) show some similarity to their calcium-based analogues and are very different from those of yttrium- and lanthanum-based metallofuller...

We report preliminary results onμ −-depolarization in C60. In contrast to graphite and diamond no clearμ −SR signal could be detected in TF-measurements in C60.

The molecular structure of C70 has been studied between 20 and 300 K using high-Q pulsed powder neutron diffraction of solid C70. The intra- and inter-molecular pair correlation functions were decoupled, allowing accurate determination of the intramolecular structure of C70. The CC bond lengths range between ≈ 1.38 and 1.48 Å with no evidence of p...

We report the results of neutron-diffraction and low-energy neutron-inelastic-scattering experiments on high-purity solid C70 between 10 and 640 K. Thermal hysteresis effects are found to accompany structural changes both on cooling and on heating. The observed diffuse scattering intensity does not change with temperature. At 10 K broad librational...

The standard enthalpy of formation of buckminsterfullerene (C60) in the crystalline state has been determined as 2278.1 ± 14.4 kJ mol–1 using a microcombustion calorimeter. Statistical mechanical calculations of the heat capacity of gaseous C60 as a function of the temperature and a critical survey of the literature data for the enthalpy of sublima...

We report the results of an avoided-level-crossing muon spin resonance study of a muonated radical of C[sub 70] between 73 and 310 K. The temperature-dependent averaging of the anisotropic hyperfine interaction of the polarized muon spin label is interpreted in terms of the reorientation dynamics of the fullerene. Uniaxial rotation about the long m...

The pressure dependence of the structure of solid C70 at ambient temperature has been measured to 25 GPa by energy-dispersive X-ray diffraction. The face-centred cubic structure transforms irreversibly to a rhombohedral phase at 0.35 GPa. Crystalline C70 is stable to 18 GPa when a phase change to amorphous carbon occurs. C70 has a slightly smaller...