ABSTRACT
A new evaporable electron acceptor material for organic photovoltaics based on N-ethyl barbituric acid bithiophene (EBB) has been demonstrated. Bilayer devices fabricated with this non-fullerene acceptor and boron subphthalocyanine chloride (SubPc) donor produce power conversion efficiencies as high as 2.6% with an extremely large open-circuit voltage approaching 1.4 V.
ABSTRACT
Detailed electrochemical studies have been undertaken on molecular aggregation of the organic semiconductor 7,14-bis((triisopropylsilyl)-ethynyl)dibenzo[b,def]chrysene (TIPS-DBC), which is used as an electron donor material in organic solar cells. Intermolecular association of neutral TIPS-DBC molecules was established by using (1)H NMR spectroscopy as well as by the pronounced dependence of the color of TIPS-DBC solutions on concentration. Diffusion limited current data provided by near steady-state voltammetry also reveal aggregation. Furthermore, variation of concentration produces large changes in shapes of transient DC and Fourier transformed AC (FTAC) voltammograms for oxidation of TIPS-DBC in dichloromethane. Subtle effects of molecular aggregation on the reduction of TIPS-DBC are also revealed by the highly sensitive FTAC voltammetric method. Simulations of FTAC voltammetric data provide estimates of the kinetic and thermodynamic parameters associated with oxidation and reduction of TIPS-DBC. Significantly, aggregation of TIPS-DBC facilitates both one-electron oxidation and reduction by shifting the reversible potentials to less and more positive values, respectively. EPR spectroscopy is used to establish the identity of one-electron oxidized and reduced forms of TIPS-DBC. Implications of molecular aggregation on the HOMO energy level in solution are considered with respect to efficiency of organic photovoltaic devices utilizing TIPS-DBC as an electron donor material.
ABSTRACT
A structure-device performance correlation in bulk heterojunction solar cells for new indandione-derived small molecule electron acceptors, FEHIDT and F8IDT, is presented. Devices based on the former exhibit higher power conversion efficiency (2.4%) and higher open circuit voltage, a finding consistent with reduced intermolecular interactions.
Subject(s)
Electrons , Indans/chemistry , Solar Energy , Electric Power Supplies , Molecular Structure , SolutionsABSTRACT
A series of 2-phenylimidazo[1,2-b]pyridazine derivatives were synthesized and evaluated for their in vitro anthelmintic activity against Haemonchus contortus. The most active compounds had in vitro LD(99) values of 30nM, which is comparable to that of the benchmark commercial nematocide, Ivermectin.
Subject(s)
Antinematodal Agents/chemistry , Haemonchus/drug effects , Pyridazines/chemistry , Animals , Antinematodal Agents/chemical synthesis , Antinematodal Agents/pharmacology , Haemonchus/growth & development , Ivermectin/chemistry , Ivermectin/pharmacology , Larva/drug effects , Pyridazines/chemical synthesis , Pyridazines/pharmacology , Structure-Activity RelationshipABSTRACT
A series of hydrazonotrifluorosulfonanilide derivatives were synthesized and evaluated for in vitro activity against the ectoparasites Ctenocephalides felis and Rhipicephalus sanguineus. Some compounds with excellent activity against tick were identified.
Subject(s)
Antiparasitic Agents/chemistry , Hydrazones/chemistry , Sulfonamides/chemistry , Animals , Antiparasitic Agents/chemical synthesis , Antiparasitic Agents/pharmacology , Cats , Dogs , Drug Discovery , Hydrazones/chemical synthesis , Hydrazones/pharmacology , Rhipicephalus sanguineus/drug effects , Structure-Activity Relationship , Sulfonamides/chemical synthesis , Sulfonamides/pharmacologyABSTRACT
A series of novel 2-alkoxy- and 2-aryloxyiminoalkyl trifluoromethanesulfonanilide derivatives have shown significant in vitro parasiticidal activity against the ectoparasites Ctenocephalides felis and Rhipicephalus sanguineus. A number of these compounds also displayed significant in vitro endoparasite activity against the nematode Haemonchus contortus.
Subject(s)
Antiparasitic Agents/chemistry , Antiparasitic Agents/pharmacology , Rhipicephalus sanguineus/drug effects , Siphonaptera/drug effects , Sulfonamides/chemistry , Sulfonamides/pharmacology , Animals , Haemonchus/drug effects , Structure-Activity RelationshipABSTRACT
A series of 2-phenyl-3-(1H-pyrrol-2-yl)acrylonitrile derivatives were synthesized and evaluated for in vitro activity against the endoparasite Haemonchus contortus and the ectoparasite Ctenocephalides felis. Some compounds had significant in vitro activity against these parasites.