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The synthesis, characterisation and photovoltaic performance of an indacenodithiophene (IDT)-based organic dye in DSSCs has been presented. The dye was designed with a novel A–D–A system, which combines the advantages of a large, π-extended donor core, flanked with double acceptor/anchoring groups. The studies presented herein illustrate the utility of the IDT core as an efficient energy-level mediator, and fluorescence resonance energy-transfer module operating via intramolecular charge transfer (ITC). In contrast to the current dyes used for DSCCs, the excitation in the IDT moiety occurs symmetrically along the long axis of the molecule, representing a new pathway of development of DSSCs. This compact system when fabricated into a metal free dye sensitized solar cell achieves promising power conversion efficiency of up to 4.2%, with a high short-circuit current density (Jsc) of 11.69 mA cm−2 and open-circuit voltage (Voc) of 0.6 V and fill factor (FF) of 0.6 under AM 1.5 irradiation (100 mW cm2). [ABSTRACT FROM AUTHOR]

New low band gap copolymers P1–P4, based on thienylenevinylene (TV) and pyrrolo[3,2-d:4,5-d′]bisthiazole (PBTz) units composed of different alkyl side chains, such as 2-octyldodecyl (OD), n-hexadecyl (HD), 2-ethylhexyl (EH), and 9-heptadecyl (HD) groups, respectively, have been synthesized and characterized. Electrochemical and optical studies of the copolymers indicated low energy band gaps in the range of 1.40–1.47 eV. Moreover, theoretical calculation with density functional theory (DFT) and time-dependent DFT calculations demonstrated that the energy band gaps, HOMO energy levels and maximum absorption values in the copolymers were in good agreement with the experimental results. The decomposition temperature of all copolymers was measured to be above 340 °C by thermogravimetric analysis (TGA), which indicates high thermal stability. Thermally annealed OTFT devices based on P1–P4 thin films demonstrated a range of hole mobilities; thus, the P2 based OTFT device exhibited the highest hole mobility of 0.062 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

We report a micelle-templated method to enhance the reactivity of DNA with highly hydrophobic molecules. Lipids, chromophores and polymers can be conjugated to DNA in high yield and under mild conditions. This method expands the range of DNA-templated reactions for DNA-encoded libraries, oligonucleotide and drug delivery, nanopore mimetics and DNA nanotechnology. [ABSTRACT FROM AUTHOR]

Reactions of (1) [Q]2[Fe4S4(SC(CH3)3)4] and the fluorous thiols HS(CH2)nRf8 (n = 2, 3; Rf8 = (CF2)7CF3)), or (2) [Na]2[Fe4S4(S(CH2)nRf8)4] (n = 2, 3) and [PhCH2P((CH2)3Rf6)3][Br] or [PPN][Cl] (PPN = Ph3P⋯N⋯PPh3), give the title compounds [Q]2[Fe4S4(S(CH2)nRf8)4], comprised of a fluorous dianion and in some cases fluorous cations, with (1) Q/n = Ph4P/2 (4, 67%), Ph4P/3 (5, 67%), Me4N/3 (69%), and Ph3P(CH2)2Rf6/2 (73%) or (2) PhCH2P((CH2)3Rf6)3/2 (14, 39%), PhCH2P((CH2)3Rf6)3/3 (15, 63%), and PPN/2 (36%). The educt [Ph3P(CH2)2Rf6]2[Fe4S4(SC(CH3)3)4] is in turn prepared from FeCl3, HSC(CH3)3/CH3ONa, and [Ph3P(CH2)2Rf6][I], and the educts [Na]2[Fe4S4(S(CH2)nRf8)4] from [Na]2[Fe4S4(SC(CH3)3)4] and HS(CH2)nRf8. The SCH21H and 13C NMR signals of these paramagnetic salts appear 8.7–10.3 and 32.3–34.9 ppm downfield from those of the corresponding thiols, but the chemical shifts of other signals are nearly normal. The UV-visible spectra show bands similar to those of non-fluorous analogs (290–298 nm and 406–415 nm; ε = 25 700 and 19 200 M−1 cm−1 for 5). The singly fluorous salts are soluble in organic solvents of moderate polarity, but not in fluorous solvents. The doubly fluorous salts 14, 15 are soluble in all fluorous solvents assayed, with partition coefficients of ＞99.65 : ＜0.35 (CF3C6F11/toluene) and 93.2–93.1 : 6.9–6.8 (FC-72/THF). Cyclic voltammograms carried out using a platinum working microelectrode show that 4 is 0.08 V thermodynamically easier to reduce than 5. [ABSTRACT FROM AUTHOR]

The fluorous alkenes H 2 C[double bond, length as m-dash]CHR fn (R fn = (CF 2 ) n-1 CF 3 ; n = 8, 10) undergo the Mizoroki-Heck reaction with a variety of aromatic monobromides and polybromides such as 1,3- and 1,4-C 6 H 4 Br 2 , 1,3,5-C 6 H 3 Br 3 , 1,3,5-C 6 H 3 Br 2 Cl, 1,4-XC 6 H 4 Br (X = CF 3 , R f8 , COCH 3 , CN, 1,4-OC 6 H 4 Br), 1,2-O 2 NC 6 H 4 Br, 5-bromoisoquinoline, 5-bromopyrimidine, 3-bromo-5-methoxypyridine, and 3,5-dibromopyridine (sixteen examples, 78% average isolated yield). Typically, 1.2-2.4 equiv. of alkene are employed per Ar-Br bond, together with Pd(OAc) 2 catalyst (4-5 mol%/Ar-Br bond), n-Bu 4 N + Br - (0.8-1.0 equiv./Ar-Br bond), NaOAc (1.2-2.4 equiv./Ar-Br bond), and 3 : 1 w/w DMF/THF as solvent (120 °C). No effort is necessary to exclude air or moisture, and reactions may be conducted on >10 g scales. Only E isomers of the products Ar(CH[double bond, length as m-dash]CHR fn ) m are detected. Thirteen representative examples are hydrogenated (Pd/C, balloon pressure H 2 ), giving Ar(CH 2 CH 2 R fn ) m (92% average isolated yield).