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A series of symmetrically bis?4?methoxybenzyl (4MB) N?substituted 1,4?diketopyrrolo[3,4?c]pyrrole (DPP) derivatives have been synthesized. The 4MB unit makes the DPP core soluble, and shows subtle modification of up to 0.2?eV in ground and excited states of the core when compared with related alkyl derivatives. Absorption and emission spectroscopy, as well as electrochemical and computational methods have been employed to prove the importance of the peripheral aryl units on the donor/ acceptor properties of the molecules. The 4MB products are highly fluorescent (quantum yields approaching 100?% in solution), with a unique distribution of frontier states shown by spectroelectrochemistry. The solid?state fluorescence correlates with the X?ray crystal structures of the compounds, a Stokes shift of approximately 80?nm is seen for two of the compounds. The frontier energy levels show that this subtle substitutional change could be of future use in molecular energy level tailoring in these, and related, materials for organic (opto)electronics.

Rice (Oryza sativa L.) is a key component of the diet of billions of humans, thus rice is a main agricultural product in many regions, particularly in eastern Arkansas, USA. Rice production is known to be a source of greenhouse gases, namely methane (CH4), but, under certain conditions, nitrous oxide (N2O) as well. The objective of this study was to evaluate the effects of tillage practice [conventional tillage (CT) and no-tillage (NT)] and urea fertilizer type [N-(n-butyl) thiophosphoric triamide (NBPT)-coated and non-coated urea] on N2O fluxes, season-long N2O emissions, and the global warming potential (GWP) from rice grown in eastern Arkansas in a direct-seeded, delayed-flood production system on a silt-loam soil.

Methane (CH4) emissions from rice (Oryza sativa L.) production are a source of concern in the environmental and agricultural communities. New and/or revised agronomic methodologies will be needed to identify production practice combinations that reduced CH4 emissions without decreasing yields or milling quality. The objective of this study was to evaluate the effects of water management (i.e., full-season flood and mid-season drain) and cultivar (i.e., pure-line cultivar LaKast and the RiceTec hybrid XL753) on CH4 fluxes and season-long emissions from rice grown in the direct-seeded, delayed-flood production system on a silt-loam soil in east-central Arkansas.

The synthesis, spectroelectrochemical and structural characteristics of highly electron-accepting diketopyrrrolopyrrole (DPP) molecules with adjoining pyridinium rings is reported, along with an assessment of their toxicity, which is apparently low. The compounds show reversible electrochemistry and in one subfamily a massive increase in molar extinction coefficient upon electrochemical reduction., This work was supported by the University of Nottingham through the Beacon of Excellence Propulsion Futures and the EPSRC through the LDMI DTP for funding. The Diamond Light Source Ltd (beamline I19) is thanked for access to collect diffraction data of crystals., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).