The fullerene adducts 1a and 1b, whose molecular shapes either promote or hinder the formation of 1-D stacks, have been examined for their potential to form 1-D wire-like domains in bulk-heterojunction organic solar cells. The photovoltaic efficiency of solar cells based on blends of the stacking fullerene 1a with regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) is greatly enhanced compared to nonstacking model fullerene 1b.

Gold(I), silver(I), and copper(I) phosphine complexes of 6,9,12,15,18-pentaaryl[60]fullerides 1a and 1b, namely, [(4-MeC(6)H(4))(5)C(60)]Au(PPh(3)) (2a), [(4-t-BuC(6)H(4))(5)C(60)]Au(PPh(3)) (2b), [(4-MeC(6)H(4))(5)C(60)]Ag(PCy(3)) (3a), [(4-t-BuC(6)H(4))(5)C(60)]Ag(PPh(3)) (3b), [(4-t-BuC(6)H(4))(5)C(60)]Ag(PCy(3)) (3c), [(4-MeC(6)H(4))(5)C(60)]Cu(PPh(3)) (4a), and [(4-t-BuC(6)H(4))(5)C(60)]Cu(PPh(3)) (4b), have been synthesized and characterized spectroscopically. All complexes except for 3c were also characterized by single-crystal X-ray diffraction. Several coordination modes between the cyclopentadienyl ring embedded in the fullerene and the metal centers are observed, ranging from η(1) with a slight distortion toward η(3) in the case of gold(I), to η(2)/η(3) for silver(I), and η(5) for copper(I). Silver complexes 3a and 3b are rare examples of crystallographically characterized Ag(I) cyclopentadienyls whose preparation was possible thanks to the steric shielding provided by fullerides 1a and 1b, which stabilizes these complexes. Silver complexes 3a and 3b both display unexpected coordination of the cyclopentadienyl portion of the fulleride anion with Ag(I). DFT calculations on the model systems (H(5)C(60))M(PH(3)) and CpMPH(3) (M = Au, Ag, or Cu) were carried out to probe the geometries and electronic structures of these metal complexes.

We have synthesized a series of pentaarylfullerene derivatives and incorporated them into bulk-heterojunction (BHJ) solar cells using poly(3-hexylthiophene) as the electron donating material. Through a combination of grazing incidence X-ray diffraction and atomic force microscopy we see two distinct nanoscale morphologies emerge across the series. Investigating the device physics using J–V characterization, light intensity dependence, and fluorescence quenching studies, we are able to correlate the morphology to the device physics. This has afforded the opportunity to clearly see how altering the nanoscale phase segregation can change the distinct physical processes occurring within a BHJ solar cell. We observe an order of magnitude increase in the efficiency of devices that utilize self-assembling fullerene derivatives over their nonassembled counterparts. More importantly, however, these results allow us to shed light on the mechanism behind this differential phase segregation using a fullerene self-assembly model. On the basis of the data, we propose new design rules for the structure of future generations of fullerene electron accepting materials for use in BHJ solar cells.

The efficiency of bulk heterojunction (BHJ) organic photovoltaics is sensitive to the morphology of the fullerene network that transports electrons through the device. This sensitivity makes it difficult to distinguish the contrasting roles of local electron mobility (how easily electrons can transfer between neighboring fullerene molecules) and macroscopic electron mobility (how well‐connected is the fullerene network on device length scales) in solar cell performance. In this work, a combination of density functional theory (DFT) calculations, flash‐photolysis time‐resolved microwave conductivity (TRMC) experiments, and space‐charge‐limit current (SCLC) mobility estimates are used to examine the roles of local and macroscopic electron mobility in conjugated polymer/fullerene BHJ photovoltaics. The local mobility of different pentaaryl fullerene derivatives (so‐called ‘shuttlecock’ molecules) is similar, so that differences in solar cell efficiency and SCLC mobilities result directly from the different propensities of these molecules to self‐assemble on macroscopic length scales. These experiments and calculations also demonstrate that the local mobility of phenyl‐C60 butyl methyl ester (PCBM) is an order of magnitude higher than that of other fullerene derivatives, explaining why PCBM has been the acceptor of choice for conjugated polymer BHJ devices even though it does not form an optimal macroscopic network. The DFT calculations indicate that PCBM's superior local mobility comes from the near‐spherical nature of its molecular orbitals, which allow strong electronic coupling between adjacent molecules. In combination, DFT and TRMC techniques provide a tool for screening new fullerene derivatives for good local mobility when designing new molecules that can improve on the macroscopic electron mobility offered by PCBM.

The relationship between the size of the substituents of aryl groups in a series of fifteen 6,9,12,15,18-pentaaryl-1-hydro[60]fullerenes and the solid-state structures and packing motifs of these compounds has been analyzed. Pentaarylfullerenes have a characteristic "badminton shuttlecock" shape that causes several derivatives to crystallize into columnar stacks. However, many pentaarylfullerenes form non-stacked structures with, for example, dimeric, layered, diamondoid, or feather-in-cavity relationships between molecules. Computational modeling gave a qualitative estimate of the best shape match between the ball and socket surfaces of each pentaarylfullerene. The best match was for pentaarylfullerenes with large, spherically shaped para-substituents on the aryl groups. The series of pentaarylfullerenes was characterized by single-crystal X-ray diffraction. A total of 34 crystal structures were obtained as various solvates and were categorized by their packing motifs.

Two gold(I) complexes, (Ph(3)P)Au[C(60)(4-MeC(6)H(4))(5)] (1) and (Ph(3)P)Au[C(60)(4-t-BuC(6)H(4))(5)] (2), were prepared in excellent yield and characterized by single-crystal X-ray diffraction. Complex 1, grown from two solvent systems, has different coordination modes of the fullerene-embedded Cp ring to the (PPh(3))Au fragment. For 1.(ODCB)(2), the cyclopentadienyl ring coordinates to the (Ph(3)P)Au fragment in an eta(1) fashion distorted toward eta(3) geometry, while in 1.(CHCl(3))(2)(CS(2)), crystal packing forces produce enough distortion to give near eta(2) coordination.

This study aims to determine the levels of heavy metals (cadmium, copper, nickel and lead) in imported and domestically produced rice grains sold in Malaysia market. A total of 10 brands of rice samples was purchased from the local market and analyzed using atomic absorption spectroscopy (AAS). Good linearity was observed over the range studied with a correlation coefficients (R2) of 0.9884-0.9999. The range values of the metals detected in rice grain samples were 0.67-0.8 mg/kg for cadmium, 2.14-7.0 mg/kg for copper, 1.85-2.68 mg/kg for nickel and 0.94-3.28 mg/kg for lead. The mean value of rice obtained were above the permitted level set by the Malaysia Food Act 1983 (Act 281) and Food and Agriculture Organization of the United Nations/ World Health Organization (FAO/WHO) (2015). The Provisional Tolerance Weekly Intake (PTWI) calculated were also above the prescribed limit except for copper.

A direct template based on vertically oriented tetraaniline provides a new, general route towards vertically oriented nanopillar and nanotube arrays for a wide variety of materials. The arrays can also be patterned at micron-resolution.