Dynamic HPLC study of C70 chlorination reveals a surprisingly selective synthesis of C70Cl8.

A dynamic HPLC study of C(70) chlorination led to the discovery, isolation, characterization, and development of the efficient preparatory procedures for two previously unknown soluble chlorofullerenes C(70)Cl(8) and C(70)Cl(6) and for insoluble [C(70)Cl(8)](n). A novel synthesis of 99% pure C(70)Cl(10) with a nearly quantitative yield was also developed. The first stability study of C(70)Cl(10,8,6) in solution showed that these compounds are very light-sensitive.

Soluble chlorofullerenes C(60)Cl(2,4,6,8,10). Synthesis, purification, compositional analysis, stability, and experimental/theoretical structure elucidation, including the X-ray structure of C(1)-C(60)Cl(10).

The efficacy of various analytical techniques for the characterization of products of C(60) chlorination reactions were evaluated by (i) using samples of C(60)Cl(6) of known purity and (ii) repeating a number of literature syntheses reported to yield pure C(60)Cl(n) compounds. The techniques were NMR, UV-vis, IR, and Raman spectroscopy, FAB, MALDI, LDI, ESI, and APCI mass spectrometry, HPLC, TGA, elemental analysis, and single-crystal X-ray diffraction. Most of these techniques are shown to give ambiguous or erroneous results, calling into question the composition and/or purity of nearly all C(60)Cl(n) compounds reported to date.

Growth of p- and n-dopable films from electrochemically generated C60 cations.

The formidable electron-acceptor properties of C60 contrast with its difficult oxidations. Only recently it has become possible to achieve reversibility of more than one electrochemical anodic process versus the six reversible cathodic reductions. Here we exploit the reactivity of electrochemical oxidations of pure C60 to grow a film of high thermal and mechanical stability on the anode.

Application and evaluation of solvent-free matrix-assisted laser desorption/ionization mass spectrometry for the analysis of derivatized fullerenes.

A variety of derivatized fullerenes have been studied by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Of particular emphasis has been the evaluation of a recently introduced solvent-free sample/target preparation method. Solvent-free MALDI is particularly valuable in overcoming adverse solvent-related effects, such as insolubility and/or degradation of the sample.

In-plume thermodynamics of the MALDI generation of fluorofullerene anions.

The mechanism of formation of fluorofullerene (FF) negative ions derived from the compounds C(60)F(18), C(60)F(36), and C(60)F(48) was studied by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (ToF) mass spectrometry (MS). A combined experimental/theoretical approach provides compelling evidence of nondissociative, thermodynamically controlled electron transfer from matrix-derived negative ions to the FF analyte as the main secondary-ionization process. Consistent with this thermochemical model, analyte parent molecular ion yield and degree of fragmentation for a particular MALDI experiment was found to depend on the nature of the matrix material (the five matrices investigated were sulfur, trans-2-[3-{4-tert-butylphenyl}-2-methyl-2-propenylidene]malononitrile, 9-nitroanthracene, 2,6-bis((furan-2-yl)methylene)cyclohexanone, and 2,6-bis((thiophen-2-yl)methylene)cyclohexanone).

Electron transfer reactivity in matrix-assisted laser desorption/ionization (MALDI): ionization energy, electron affinity and performance of the DCTB matrix within the thermochemical framework.

DCTB [(H(3)C)(3)C-p-Ph-CH=C(CH(3))-trans-CH=C(CN)(2)] has recently advanced to the most promising matrix material for matrix-assisted laser desorption/ionization (MALDI) within material sciences. However, data that would allow the evaluation of the electron-transfer reactivity within a thermochemical framework are sparse. The present study reports the first-time determination of the ionization energy (IE) of DCTB applying photoelectron (PE) spectroscopy.

Seven-minute synthesis of pure C(s)-C60Cl6 from [60]fullerene and iodine monochloride: first IR, Raman, and mass spectra of 99 mol % C60Cl6.

Three previously reported procedures for the synthesis of pure C(s)-C60Cl6 from C60 and ICl dissolved in benzene or 1,2-dichlorobenzene were shown to actually yield complex mixtures of products that contain, at best, 54-80% C(s)-C60Cl6 based on HPLC integrated intensities. MALDI mass spectrometry was used for the first time to identify other components of the reaction mixtures. An improved synthetic procedure was developed for the synthesis of about 150 mg batches of chlorofullerenes containing 90% C(s)-C60Cl6 based on HPLC intensities.

Formation of long-lived fluorofullerene trianions in collisions with Na.

The first experimental observation of long-lived triply charged fluorofullerene anions in the gas phase obtained from C60F48 is reported. The existence of a Coloumb barrier trapping the third electron in the trianion is supposed to be responsible for detection of the species which is estimated to have negative third electron affinity.