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Inversion of the connections of amidine linkers combined with controlled oligothiophene chain catenation in oligothiophene-naphthalimide assemblies provides an efficient method to tune the HOMO and LUMO values in this type of assemblies. This modification also suppresses the intramolecular charge transfer (ICT) band normally found in this type of derivatives, also delocalizing the frontier molecular orbitals over the whole conjugated skeleton. The resultant assemblies were used in the fabrication of field-effect transistors, which showed well-balanced ambipolar transport. [ABSTRACT FROM AUTHOR]

Pharmacokinetics (PK), pharmacodynamics (PD), and PK/PD ratios of a new solvate of enrofloxacin (enrofloxacin hydrochloride-dihydrate; enro-C), were studied in hamsters. Enrofloxacin from Baytril® 5% (enroR) served as the reference preparation. Two groups of 60 Syrian golden hamsters were intramuscularly injected individually with 10 mg/kg of enroR or with enro-C. Tissue and serum samples were obtained for 72 h; enrofloxacin concentrations were determined by HPLC with UV detection. Ninety percent minimum inhibitory concentrations (MIC90) were determined for strains of methicillin-resistant Staphylococcus aureus, Leptospira interrogans, and Escherichia coli. All PK variables were statistically different between groups (P < 0.01). CMAX of enrofloxacin for enro-C was 17.3 µg/mL and it was 2.6 µg/mL for enroR. AUC was considerably higher for enro-C (459.2 µg/mL h vs. 19.9 µg/mL h). There were no statistically significant differences in MIC90 values between enroR and enro-C. Tissue concentrations of enro-C in all cases were higher and remained above the MIC for longer periods than those of enroR. Relevant PK/PD ratios for enrofloxacin (AUC/MIC ≥ 125 and CMAX > MIC = 10-12) are consequently superior for enro-C. Given the outstanding PK/PD ratios of enro-C, this new moiety is proposed as a possible solution when high tissue concentrations of enrofloxacin are necessary. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are emerging materials with structural modularity that allows their application in many fields. The aim of this work is to determine the environmental impact of using an imine based covalent organic framework (RT-COF-1) for both surface printing (Case A) and 3D inkjet printing (Case B) by applying Life Cycle Assessment (LCA) methodology. Experimental data on RT-COF-1 synthesis as well as results obtained by simulation of their precursors production, 1,3,5-tris-(4-aminophenyl) benzene (TAPB) and 1,3,5-benzenetricarbaldehyde (BTCA), are used. LCA results show that monomer synthesis is the most important contributor to environmental impacts in both case studies. On the other hand, the contribution of solvents used in Case A is also remarkable. The comparison between both case studies indicates that the environmental impacts of Case B is lower than that of Case A (reduction within 5%–65%). Finally, LCA results of Case B are compared to other materials used for 3D-printing, such as polymerizable ionic liquids (PILs). The results show that RT–COF–1 compares favourably with PILs in five of nine impact categories, being especially relevant the reductions achieved in the abiotic depletion and acidification potential (>90%), in the primary energy consumption (⁓35%) and carbon footprint (⁓50%), suggesting the potential of RT–COF–1 as 3D-printing material from an environmental perspective. This work is a first step for further research to highlight the main environmental burdens of using COF-based materials in this application. [Display omitted] • LCA methodology applied to imine-based COF for inkjet printing. • 3D-printing is superior to surface printing from an environmental point of view. • Solvents and synthesis of precursors are the main contributors to overall impact. • Environmental footprint of RT–COF–1 is comparable to polymerizable ionic liquids. [ABSTRACT FROM AUTHOR]

The synthesis, characterization, and optical properties of a novel star-shaped oligothiophene with a central rigid trithienobenzene (BTT) core and diketopyrrolopyrrole (DPP) units are reported and compared with homologous linear systems based on the benzodithiophene (BDT) and the naphthodithiophene (NDT) units end capped with DPPs. This comparison is aimed at elucidating the effect of the star-shaped configuration versus linear conformation on the optical and electrical properties. Electronic and vibrational spectroscopies, together with transient absorption spectroscopy, scanning electronic microscopy, and DFT calculations are used to understand not only the molecular properties of these semiconductors, but also to analyze the supramolecular aggregation in these derivatives. We conclude that although the subject star-shaped derivative is not optimal in terms of π-conjugation, its extended BTT unit significantly favors intermolecular π-stacking interactions, which is interesting for their applications in devices. Field-effect transistors and solar cells were fabricated with these new molecular semiconductors and the performance difference discussed. [ABSTRACT FROM AUTHOR]

Abstract: New luminescent polymers containing two individual emission species-poly(fluorene-alt-phenylene) as a blue host and variable amounts of 1,8-naphthalimide as red dopant have been designed and synthesized. Optical studies (optical absorption (OA) and steady-state photoluminescence emission (PL)) in diluted solutions and thin solid films reveal that the emission spectrum can be tuned by varying the content of 1,8-naphthalimide moieties. Although no significant interaction can be observed between both moieties in the ground state, after photoexcitation an efficient energy transfer takes place from the PFP backbone to the red chromophore, indeed, by adjusting the polymer/naphthalimide ratio it is possible to obtain single polymers which emit white light to the human eye in solid state. Energy transfer is more effective in the co-polymers than in physical mixtures of the two chromophores. We prepared single-layer electroluminescent simple devices with structure: ITO/poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT:PSS)/active layer/Ba/Al. With this single layer–single component device structure, white light with Commission Internationale de l’Eclairage (CIE) color coordinates (0.3, 0.42) is obtained for the electroluminescence (EL) emission with an efficiency of 22.62Cd/A. [Copyright &y& Elsevier]