V-Shaped Tröger Oligothiophenes Boost Triplet Formation by CT Mediation and Symmetry Breaking.

A new family of molecules obtained by coupling Tröger's base unit with dicyanovinylene-terminated oligothiophenes of different lengths has been synthesized and characterized by steady-state stationary and transient time-resolved spectroscopies. Quantum chemical calculations allow us to interpret and recognize the properties of the stationary excited states as well as the time-dependent mechanisms of singlet-to-triplet coupling. The presence of the diazocine unit in Tröger's base derivatives is key to efficiently producing singlet-to-triplet intersystem crossing mediated by the role of the nitrogen atoms and of the almost orthogonal disposition of the two thiophene arms. Spin-orbit coupling-mediated interstate intersystem crossing (ISC) is activated by a symmetry-breaking process in the first singlet excited state with partial charge transfer character. This mechanism is a characteristic of these molecular triads since the independent dicyanovinylene-oligothiophene branches do not display appreciable ISC. These results show how Tröger's base coupling of organic chromophores can be used to improve the ISC efficiency and tune their photophysics.

Photocatalytic degradation of organic pollutants through conjugated poly(azomethine) networks based on terthiophene-naphthalimide assemblies.

A conjugated poly(azomethine) network based on ambipolar terthiophene-naphthalimide assemblies has been synthesized and its electrochemical and UV-vis absorption properties have been investigated. The network has been found to be a promising candidate for the photocatalytic degradation of organic pollutants in aqueous media.

Stimuli-Responsive Benzothiadiazole Derivative as a Dopant for Rewritable Polymer Blends.

A new rod-shaped benzothiadiazole fluorophore, namely, 4,7-di-(4-nonylphenyl)benzo[c][1,2,5]thiadiazole, which strongly emits fluorescence both in solution and in solid state has been synthesized, and its photophysical properties were rationalized with the help of density functional theory calculations. This molecule crystallizes in two distinct light-emitting crystalline phases, which can be interconverted in response to pressure, temperature, and solvent vapors. Powder X-ray diffraction indicates that in both polymorph, molecules adopt a lamellar packing, the different interlayer spacing being the main difference between the two structures. Single-crystal analysis of one of the polymorphs allows us to identify weak interaction planes, which presumably facilitates the polymorphic transformation through mechanically or thermally induced sliding processes. The polymorphic transformation and the origin of the switchable fluorescence have been rationalized through a spectroscopic and theoretical study. This study suggests that the different colors observed are due to different intermolecular aromatic interactions owing to the displacement of the molecules with respect to the layer normal. Interestingly, blending this molecule with a biodegradable polymer such as poly(vinyl alcohol) gives rise to a thermally activated reversible switchable fluorescent system, which entitles this material as an attractive candidate for technological applications, such as thermal sensors, security inks, or rewritable paper.

Alkamides from Tropaeolum tuberosum inhibit inflammatory response induced by TNF-α and NF-κB.

ETHNO-PHARMACOLOGICAL RELEVANCE: Tropaeolum tuberosum, commonly known as "Mashua", is one of the plants most frequently used by Andean (Peruvian-Bolivian) people as food and medicine. It is used as a remedy against a wide range of diseases, especially those related with inflammation. OBJECTIVES: This study aims to identify compounds active against inflammatory related conditions. MATERIALS AND METHODS: A bioassay-guided isolation of anti-inflammatory compounds from black and purple tubers of T. tuberosum was performed measuring TNF-α and NF-κB production in THP-1 monocytic cells. RESULTS: The bioassay-guided isolation led to one active compound from purple T. tuberosum, N-oleoyldopamine (1), and another active compound from black T. tuberosum, N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (2). Both compounds displayed anti-TNF-α activity with IC50 values of 3.12 ±â€¯0.19 µM and 1.56 ±â€¯0.15 µM, respectively. Also, both compounds suppressed NF-κB with IC50 of 3.54 ±â€¯0.02 µM and 1.77 ±â€¯0.07 µM, respectively. CONCLUSIONS: We identified bioactive compounds from purple and black Tropaeolum tuberosum responsible for their anti-inflammatory activity: N-oleoyldopamine (1) and N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (2). This is the first report which isolates these compounds from T. tuberosum and describes their anti-inflammatory activities.