Pavel A. Troshin

Two Isomers of C60F48: An Indented Fullerene

Deflated buckyballs: The single-crystal structure of C60 F48 ⋅2u2009(mesitylene) revealed the presence of both D3 and S6 isomers in the same crystal. C(sp2 )-C(sp2 ) bonds (1.30 Å) are much shorter than C(sp3 )-C(sp3 ) bonds (1.54-1.63 Å). The C60 cage is characterized by concave areas in the regions of six double bonds. Each double bond is effectively shielded by four F atoms, which accounts for the low reactivity of C60 F48 .

Highly Efficient All-Inorganic Planar Heterojunction Perovskite Solar Cells Produced by Thermal Coevaporation of CsI and PbI2

We report here all inorganic CsPbI3 planar junction perovskite solar cells fabricated by thermal coevaporation of CsI and PbI2 precursors. The best devices delivered power conversion efficiency (PCE) of 9.3 to 10.5%, thus coming close to the reference MAPbI3-based devices (PCE ≈ 12%). These results emphasize that all inorganic lead halide perovskites can successfully compete in terms of photovoltaic performance with the most widely used hybrid materials such as MAPbI3.

Complexation of pyrrolidinofullerenes and zinc-phthalocyanine in a bilayer organic solar cell structure

Bilayer organic solar cells were prepared using zinc-phthalocyanine (ZnPc) and a novel, highly soluble pyrollidinofullerene bearing three chelating pyridyl groups (PyF). The formation of supramolecular complexes between the two compounds is indicated by a significantly increased solubility of ZnPc in dichloromethane upon addition of the PyF. Spin-coating a film of PyF on a vacuum-evaporated film of ZnPc results in a solar cell yielding short circuit current (Isc) densities of 3mA∕cm2 and open-circuit voltages (Voc) of about 0.4V under 100mW∕cm2 simulated AM1.5 illumination. Solar cells prepared by substituting the PyF with a fullerene derivative forming no complexes with ZnPc show significantly lower photovoltaic conversion efficiencies.

Facile preparation of amine and amino acid adducts of [60]fullerene using chlorofullerene C60Cl6 as a precursor.

We report a general synthetic approach to the preparation of highly functionalized amine and amino acid derivatives of [60]fullerene starting from readily available chlorofullerene C(60)Cl(6). The synthesized water-soluble amino acid derivative of C(60) demonstrated pronounced antiviral activity, while the cationic amine-based compound showed strong antibacterial action in vitro.

Bromination of [60]Fullerene. II. Crystal and Molecular Structure of [60]Fullerene Bromides, C60Br6, C60Br8, and C60Br24

Abstract The crystal and molecular structures of the bromofullerene solvates C60Br6·0.5C6H5Cl·0.5Br2, C60Br8·1.5(o‐C6H4Cl2), C60Br8·Br2, C60Br8·0.5C6H5Br·0.5Br2, and C60Br24·2Br2 have been determined by single crystal X‐ray diffraction. The molecular species C60Br6, C60Br8, and C60Br24 which have idealized C s , C 2v , and T h symmetries, respectively, have several different types of C‒Br and C‒C bonds. A comparison between different solvates of the same bromofullerenes revealed a larger stability of the packing modes for the C60Br6 and C60Br24 solvates, whereas the C60Br8 solvates showed different packing motifs dependent on the nature and amount of the solvent molecules.

Bromination of [60]Fullerene. I. High‐Yield Synthesis of C60Br x (x=6, 8, 24)

Abstract The systematic study of the bromination of C60 was performed under various experimental conditions. Application of some chloroarenes as reaction media resulted in the high‐yield (70–96%) selective synthesis of C60Br6 and C60Br8. Direct bromination of fullerene yielded either C60Br8, C60Br14, or C60Br24 depending on the reaction time. Possible pathways of bromination of C60Br8 were analyzed using semiempirical (AM1) calculations, two most probable molecular structures are conjectured for the first isolated C60Br14.

Synthesis of Fullerenols from Halofullerenes

Abstract Halogenated fullerenes were used as reagents to prepare fullerenols. Depending on reaction conditions two types of substances (complex mixtures of products with average compositions C60OnHm, n=10–26, m=14–30 and C60OnHmMk, M=K, Na; n=17–24, m=16–28, k=3–8) possessing essentially different water solubility were obtained. Highly soluble metal‐containing species are most likely ionic compounds similar to metal derivatives of alcohols–alcoholates. An electron withdrawing effect of the carbon cage could make alkali metal fullerenolates (C60(OH)x(OM)y) inert towards hydrolysis. Halogens were selectively substituted when fullerene bromides and chlorides were treated with silver trifluoroacetate. Fullerenol esters C60(OOCCF3)n formed were then hydrolyzed to form C60(OOCCF3)x(OH)y. Attempts to cleave all ester groups in C60(OOCCF3)x(OH)y failed in acidic media, while alkaline hydrolysis was accompanied by unselective polyhydroxylation of the fullerene cage.

Probing the Intrinsic Thermal and Photochemical Stability of Hybrid and Inorganic Lead Halide Perovskites

We report a careful and systematic study of thermal and photochemical degradation of a series of complex haloplumbates APbX3 (X = I, Br) with hybrid organic (A+ = CH3NH3) and inorganic (A+ = Cs+) cations under anoxic conditions (i.e., without exposure to oxygen and moisture by testing in an inert glovebox environment). We show that the most common hybrid materials (e.g., MAPbI3) are intrinsically unstable with respect to the heat- and light-induced stress and, therefore, can hardly sustain the real solar cell operation conditions. On the contrary, the cesium-based all-inorganic complex lead halides revealed far superior stability and, therefore, provide an impetus for creation of highly efficient and stable perovskite solar cells that can potentially achieve pragmatic operational benchmarks.

Efficient 2 + 3 Cycloaddition Approach to Synthesis of Pyridinyl Based [60]Fullerene Ligands

Abstract [60]Fullerene reacts with azomethine ylids generated from 2‐ and 4‐picolylamines to form corresponding fulleropyrrolidines bearing pyridinyl substituents. X‐ray single crystal structure of the first dyad formed via coordination of ZnTPP to the fulleropyrrolidine nitrogen is reported.

The activity of [60]fullerene derivatives bearing amine and carboxylic solubilizing groups against Escherichia coli : a comparative study

We report a comparative investigation of the antibacterial activity of two water-soluble fullerene derivatives bearing protonated amine (AF) and deprotonated carboxylic (CF) groups appended to the fullerene cage via organic linkers. The negatively charged fullerene derivative CF showed no tendency to bind to the bacterial cells and, consequently, no significant antibacterial activity. In contrast, the compound AF loaded with cationic groups showed strong and partially irreversible binding to the negatively charged Escherichia coli K12 TG1 cells and to human erythrocytes, also possessing negative zeta potential. Adsorption of AF on the bacterial surface was visualized by atomic force microscopy revealing the formation of specific clusters (AF aggregates) surrounding the bacterial cell. Incubation of E. coli K12 TG1 with AF led to a dose-dependent bactericidal effect with LD50 = 79.1 µM. The presence of human erythrocytes in the test medium decreased the AF antibacterial activity. Thus we reveal that the water-soluble cationic fullerene derivative AF possesses promising antibacterial activity, which might be utilized in the development of novel types of chemical disinfectants.