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In order to establish a relationship between the structure and the optical waveguiding behavior, two series of linear bisethynylbenzenes combining trifluoromethyl and methoxy groups in the core and external rings were synthesized.

Donor–Acceptor (D–A) naphthalimides (NI) are highly fluorescent multitask compounds that have demonstrated success in a variety of optoelectronic applications, among which, thin film organic lasers (TFOLs) are not included. Here we assess the potential of various NI derivatives for lasing applications by investigating their amplified spontaneous emission (ASE) properties when dispersed in polystyrene thin films. To overcome the relatively low ASE photostability measured in the NIs, a series of peryleneimides (PI) derivatives, with similar chemical structure but with more extended π-conjugation, is synthesized and reported here, together with a complete characterization of their optical and ASE properties, both in solution and thin film. Most investigated compounds show ASE, with emissions at different wavelengths spanning from the blue to the red, depending on the derivative. Furthermore, surface emitting TFOLs with top-layer polymeric distributed feedback resonators are fabricated and characterized. This work represents an advance in the field of low-cost TFOLs, by including two families of successful laser dyes, NIs and PIs, the latter with significantly better photostability. The group at the University of Alicante acknowledges financial support from the “Ministerio de Ciencia e Innovación/Agencia Estatal de investigación” (MCIN/AEI) of Spain, European Regional Development Fund and European Social Funds (project PID2020-106114GB-I00) and from the Conselleria de Innovación, Universidades y Sociedad Digital de la Comunidad Valenciana (Grant No. AICO/2021/093). The team of the University of Castilla la Mancha acknowledges financial support from the MCIN/AEI of Spain (project PID2020-119636GB-I00 and RED2018-102331-T) and by FEDER Una manera de hacer Europa and Junta de Comunidades de Castilla-La Mancha (JCCM-FEDER) (SBPLY/17/180501/000189 and SBPLY/17/180501/000114). B. Donoso is grateful for a FPU predoctoral contract (FPU16/05099). I. Torres-Moya thanks to the Junta de Comunidades de Castilla-La Mancha for a post-doctoral contract (SBPLY/19/180501/000346). Finally, we acknowledge the computer resources, technical assistance, and expertise provided by the High Performance Computing Service of UCLM.

Pyrazine-decorated benzotriazole cores allow the orthogonal combination of two dipolar systems within a single molecule. A series of this type of derivatives was synthesized and their photophysical features were studied. The properties of these compounds showed remarkable differences in function depending on the substitution in the pyrazine ring of the benzotriazole core. Furthermore, the two-photon absorption property (2PA) was studied to determine the structure-properties relationship for the reported compounds. The best dye achieved a crosssection of 1532 GM, which was higher than values previously obtained for similar D-π-A-π-D benzotriazole derivatives. TD-DFT calculations, which supported the experimental observations, indicating the interaction between the two dipolar systems was responsible for enhancing the 2 PA properties and favoring bathochromic shifts. PCI2019-111825-2, PID2019-104293GB-I00, UMA18-FEDERJA-007, SBPLY/17/180501/000189, PID2020-119636GB-I00 , RED2018-102331-T, Universidad de Málaga / CBUA

Multifunctionality is a desirable aspect in materials science. Indeed, the development of multifunctional compounds is crucial for sustainable chemistry by saving resources and time. In this sense, 2H-benzo[d]1,2,3-triazole (BTz) is an excellent candidate with promising characteristics, including its ability to self-assemble; its acceptor character, which enables the synthesis of donor-acceptor structures; and its facile modulation using standard chemical methods. Thus, due to its interesting properties, it is possible to produce different derivatives with applications in different fields, as summarized in this article, with the correct substitution at the BTz cores. Optoelectronic or biomedical applications, amongst others, are highlighted.

Formation of all-carbon-substituted quaternary carbons is a key challenge in organic and medicinal chemistry. We report a cobalt-catalyzed C(sp3)–C(sp3) cross-coupling that allows for the introduction of benzyl, heteroarylmethylzinc and allyl groups to halo-carbonyl substrates. The cross-coupling reaction is selective for C(sp3)-over C(sp2)-halides, in contrast to most used catalytic metals, and allows access to novel scaffolds of pharmaceutical interest. NMR mechanistic studies suggest the presence of Co(0) complexes as catalytic species., La formación de carbonos cuaternarios totalmente sustituidos con carbono es un desafío clave en la química orgánica y medicinal. Presentamos un acoplamiento cruzado C(sp 3 )–C(sp 3 ) catalizado por cobalto que permite la introducción de grupos bencilo, heteroarilmetilzinc y alilo en sustratos de halocarbonilo. La reacción de acoplamiento cruzado es selectiva para C(sp 3 )-sobre C(sp 2 )-haluros, en contraste con la mayoría de los metales catalíticos utilizados, y permite el acceso a nuevos andamios de interés farmacéutico. Los estudios mecanísticos de RMN sugieren la presencia de complejos de Co(0) como especies catalíticas.

A series of donor-π-acceptor-π-donor (D-π-A-π-D) benzoazole dyes with 2H-benzo[d][1,2,3]triazole or BTD cores have been prepared and their photophysical properties characterized. The properties of these compounds display remarkable differences, mainly as a result of the electron-donor substituent. Dyes with the best properties have visible-light absorption over λ=400 nm, large Stokes shifts in the range of about 3500-6400 cm-1 , and good fluorescence emission with quantum yields of up to 0.78. The two-photon absorption properties were also studied to establish the relationship between structure and properties in the different compounds synthesized. These results provided cross sections of up to 1500 GM, with a predominance of S2 ←S0 transitions and a high charge-transfer character. Time-dependent DFT calculations supported the experimental results.

Donor-π-Acceptor (D-π-A) compounds based on a 1,8-naphthalimide core branched with different alkynyl donor groups have been synthesized, characterized and tested in Organic Field-Effect Transistors (OFETs) and as optical waveguides. The aim was to design materials with promising applications in new organic optoelectronic devices, namely Organic Field-Effect Optical Waveguides (OFEW). Computational studies showed that these compounds possess suitable electronic properties to behave as efficient semiconductors in OFETs and as optical waveguides. The former application is evidenced by the optimal energetic values of the frontier molecular orbitals and intramolecular reorganization energies, whereas the latter application is possible due to the high Stoke shifts and strong tendency to self-assemble. This last feature has been corroborated by NMR aggregation studies in solution. The experimental results indicate that the three studied semiconductors are active in OFETs, with electron field effect mobilities close to 10−2 cm2V−1s−1 for compound 1c. Furthermore, compound 1b also shows excellent behavior as an optical waveguide, thus making it a good candidate to be applied in OFEWs.

Precise mechanical processing of optical microcrystals involves complex microscale operations viz. moving, bending, lifting, and cutting of crystals. Some of these mechanical operations can be implemented by applying mechanical force at specific points of the crystal to fabricate advanced crystalline optical junctions. Mechanically compliant flexible optical crystals are ideal candidates for the designing of such microoptical junctions. A vapor‐phase growth of naturally bent optical waveguiding crystals of 1,4‐bis(2‐cyanophenylethynyl)benzene (1) on a surface forming different optical junctions is presented. In the solid‐state, molecule 1 interacts with its neighbors via CH⋅⋅⋅N hydrogen bonding and π–π stacking. The microcrystals deposited at a glass surface exhibit moderate flexibility due to substantial surface adherence energy. The obtained network crystals also display mechanical compliance when cut precisely with sharp atomic force microscope cantilever tip, making them ideal candidates for building innovative T‐ and Δ‐shaped optical junctions with multiple outputs. The presented micromechanical processing technique can also be effectively used as a tool to fabricate single‐crystal integrated photonic devices and circuits on suitable substrates.

2H-Benzo[d]1,2,3-triazole derivatives with a range of chemical functionalities showed significant organogel formation, particularly bis-amide derivative 4e which gave robust thermally stable gels, in a range of solvents down to 0.1 wt%. The gelators proved responsive under pH stimuli or to the presence of metal cations. The gels also proved to be useful vehicles to crystallize pharmaceutical drugs, resulting in a change in polymorphic outcome in the case of sulfathiazole compared to the solution crystallization outcome.

A series of Donor–π–Acceptor–π–Donor compounds based on a 2H-benzo[d][1,2,3]triazole core branched with different alkynyl donor groups has been characterized and tested in organic field-effect transistors (OFETs). The electronic and molecular structures were elucidated through optical and vibrational spectroscopy in conjunction with DFT calculations. The results indicate that the planarity of the structure and the good intramolecular charge transfer from the electron-donating to the electron-withdrawing fragments play a critical role in the application of the compounds as semiconductors in OFET devices. The compounds were tested in a top-contact/bottom-gate thin film transistor architecture, and they behave as p-type semiconductors.

Monomers 4,7-dibromo-2H-benzo[d]1,2,3-triazole (m1) and 4,7-(bis(4-bromophenyl)ethynyl)-2H-benzo[d]1,2,3-triazole (m2) have been synthesized in good yields using different procedures. Monomers m1 and m2 have been employed for building new copolymers of fluorene derivatives by a Suzuki reaction under microwave irradiation using the same conditions. In each case different chain lengths have been achieved, while m1 gives rise to polymers for m2 oligomers have been obtained (with a number of monomer units lower than 7). Special interest has been paid to their photophysical properties due to excited state properties of these D-A units alternates, which have been investigated by density functional theory (DFT) calculations using two methods: (i) An oligomer approach and (ii) by periodic boundary conditions (PBC). It is highly remarkable the tunability of the photophysical properties as a function of the different monomer functionalization derived from 2H-benzo[d]1,2,3-triazole units. In fact, a strong modulation of the absorption and emission properties have been found by functionalizing the nitrogen N-2 of the benzotriazole units or by elongation of the &pi, conjugated core with the introduction of alkynylphenyl groups. Furthermore, the charge transport properties of these newly synthesized macromolecules have been approached by their implementation in organic field-effect transistors (OFETs) in order to assess their potential as active materials in organic optoelectronics.

A strategic approach to control the polymorphism of two related drugs by introducing a drug-mimetic imide functional group into the molecular weight organogelator structure is presented. This was achieved with novel aminoglutethimide-derived bis(urea) organogelators designed to form gels that act as targeted crystallization media for (±)-thalidomide and barbital. The organogelators prevent concomitant crystallization, a serious issue for drug formulation and development. This work demonstrates the potential to control concomitant crystallization with rationally designed supramolecular gelators.

11 Figuras, We report here the preparation of co-assembled microcrystals by employing an easy, reproducible and cost-effective technique, namely slow diffusion. 2H-Benzo[d][1,2,3]triazole and benzo[c][1,2,5]thiadiazole were chosen as host and guest skeletons, respectively. Structural similarities allowed the correct co-assembly of the two structures. The co-assemblies were studied by different techniques that included Raman spectroscopy and X-ray diffraction, amongst others. The waveguiding properties and the emission colour of the doped organic microcrystals were also investigated. It was found that changes in the molar ratio of the different doping agents could tune the light emission. Fluorescence microscopy images of the co-assembled microcrystals revealed light colour changes from green to whitish, up to CIE coordinates of (0.370, 0.385). These tunable colour-active materials could be useful in the fields of optoelectronics or lab-on-a-chip for integrated optical circuits at micro-/nanoscale., This work has been financially supported by JCCM-FEDER (project SBPLY/17/180501/000189) and MINECO of Spain (projects CTQ2017-88158-R, CTQ2017-84825-R and RED2018-102331-T). R. Martín and B. Donoso are indebted to MEC for a FPU studentship.