Exploring the Luminescence, Redox, and Magnetic Properties in a Multivariate Metal-Organic Radical Framework.

Persistent neutral organic radicals are excellent building blocks for the design of functional molecular materials due to their unique electronic, magnetic, and optical properties. Among them, triphenylmethyl radical derivatives have attracted a lot of interest as luminescent doublet emitters. Although neutral organic radicals have been underexplored as linkers for building metal-organic frameworks (MOFs), they hold great potential as organic elements that could introduce additional electronic properties within these frameworks. Herein, we report the synthesis and characterization of a novel multicomponent metal-organic radical framework (PTMTCR@NR-Zn MORF), which is constructed from the combination of luminescent perchlorotriphenylmethyl tricarboxylic acid radical (PTMTCR) and nonemissive nonradical (PTMTCNR) organic linkers and Zn(II) ions. The PTMTCR@NR-Zn MORF structure is layered with microporous one-dimensional channels embedded within these layers. Kelvin probe force microscopy further confirmed the presence of both organic nonradical and radical linkers in the framework. The luminescence properties of the PTMTCR ligand (first studied in solution and in the solid state) were maintained in the radical-containing PTMTCR@NR-Zn MORF at room temperature as fluorescence solid-state quenching is suppressed thanks to the isolation of the luminescent radical linkers. In addition, magnetic and electrochemical properties were introduced to the framework due to the incorporation of the paramagnetic organic radical ligands. This work paves the way for the design of stimuli-responsive hybrid materials with tunable luminescence, electrochemical, and magnetic properties by the proper combination of closed- and open-shell organic linkers within the same framework.

Expanding the horizons of porphyrin metal-organic frameworks via catecholate coordination: exploring structural diversity, material stability and redox properties.

Porphyrin based Metal-Organic Frameworks (MOFs) have generated high interest because of their unique combination of light absorption, electron transfer and guest adsorption/desorption properties. In this study, we expand the range of available MOF materials by focusing on the seldom studied porphyrin ligand H10TcatPP, functionalized with tetracatecholate coordinating groups. A systematic evaluation of its reactivity with M(iii) cations (Al, Fe, and In) led to the synthesis and isolation of three novel MOF phases. Through a comprehensive characterization approach involving single crystal and powder synchrotron X-ray diffraction (XRD) in combination with the local information gained from spectroscopic techniques, we elucidated the structural features of the solids, which are all based on different inorganic secondary building units (SBUs). All the synthesized MOFs demonstrate an accessible porosity, with one of them presenting mesopores and the highest reported surface area to date for a porphyrin catecholate MOF (>2000 m2 g-1). Eventually, the redox activity of these solids was investigated in a half-cell vs. Li with the aim of evaluating their potential as electrode positive materials for electrochemical energy storage. One of the solids displayed reversibility during cycling at a rather high potential (∼3.4 V vs. Li+/Li), confirming the interest of redox active phenolate ligands for applications involving electron transfer. Our findings expand the library of porphyrin-based MOFs and highlight the potential of phenolate ligands for advancing the field of MOFs for energy storage materials.

Direct C-H Arylation of Dithiophene-Tetrathiafulvalene: Tuneable Electronic Properties and 2D Self-Assembled Molecular Networks at the Solid/Liquid Interface.

Invited for the cover of this issue is the group of Manuel Souto and co-workers at the University of Aveiro and CICECO-Aveiro Institute of Materials. The image depicts the direct C-H arylation of dithiophene-tetrathiafulvalene (DT-TTF) and the self-assembly of DT-TTF-tetrabenzoic acid studied by using scanning tunnelling microscopy. Read the full text of the article at 10.1002/chem.202300572.

Perylene-Based Coordination Polymers: Synthesis, Fluorescent J-Aggregates, and Electrochemical Properties.

The incorporation of electroactive organic building blocks into coordination polymers (CPs) and metal-organic frameworks (MOFs) offers a promising approach for adding electronic functionalities such as redox activity, electrical conductivity, and luminescence to these materials. The incorporation of perylene moieties into CPs is, in particular, of great interest due to its potential to introduce both luminescence and redox properties. Herein, we present an innovative synthesis method for producing a family of highly crystalline and stable coordination polymers based on perylene-3,4,9,10-tetracarboxylate (PTC) and various transition metals (TMs = Co, Ni, and Zn) with an isostructural framework. The crystal structure of the PTC-TM CPs, obtained through powder X-ray diffraction and Rietveld refinement, provides valuable insights into the composition and organization of the building blocks within the CP. The perylene moieties are arranged in a herringbone pattern, with short distances between adjacent ligands, which contributes to the dense and highly organized framework of the material. The photophysical properties of PTC-Zn were thoroughly studied, revealing the presence of J-aggregation-based and monomer-like emission bands. These bands were experimentally identified, and their behavior was further understood through the use of quantum-chemical calculations. Solid-state cyclic voltammetry experiments on PTC-TMs showed that the perylene redox properties are maintained within the CP framework. This study presents a simple and effective approach for synthesizing highly stable and crystalline perylene-based CPs with tunable optical and electrochemical properties in the solid state.

Direct C-H Arylation of Dithiophene-Tetrathiafulvalene: Tuneable Electronic Properties and 2D Self-Assembled Molecular Networks at the Solid/Liquid Interface.

Tetrathiafulvalene is among the best known building blocks in molecular electronics due to its outstanding electron-donating and redox properties. Among its derivatives, dithiophene-tetrathiafulvalene (DT-TTF) has attracted considerable interest in organic electronics, owing to its high field-effect mobility. Herein, we report the direct C-H arylation of DT-TTF to synthesise mono- and tetraarylated derivatives functionalised with electron-withdrawing and electron-donating groups in order to evaluate their influence on the electronic properties by cyclic voltammetry, UV-vis spectroscopy and theoretical calculations. Self-assembly of the DT-TTF-tetrabenzoic acid derivative was studied by using scanning tunnelling microscopy (STM) which revealed the formation of ordered, densely packed 2D hydrogen-bonded networks at the graphite/liquid interface. The tetrabenzoic acid derivative can attain a planar geometry on the graphite surface due to van der Waals interactions with the surface and H-bonding with neighbouring molecules. This study demonstrates a simple method for the synthesis of arylated DT-TTF derivatives towards the design and construction of novel π-extended electroactive frameworks.

Auto-regulação e consumo de álcool em adolescentes do distrito de Viseu / Self-regulation and alcohol consumption in adolescents from the district of Viseu

Enquadramento: A adolescência caracteriza-se por ser uma etapa do ciclo vital onde o desejo de experimentação e de exploração de novas sensações conduz muitos adolescentes à iniciação no consumo de álcool, com consequências nefastas para a saúde do jovem. O comportamento auto-regulado em saúde compreende o controlo das necessidades mais imediatas (controlo de impulsos) e a mobilização de pensamentos, sentimentos e comportamentos para objectivos de saúde a longo prazo. Objectivos: Analisar a relação entre as variáveis sociodemográficas, de contexto escolar, estilos de vida, envolvimento e expectativas face ao álcool e variáveis psicológicas (autoestima e autoconceito) com as competências de auto-regulação em adolescentes do ensino secundário do distrito de Viseu. Métodos: Recorreu-se a um modelo de investigação quantitativo, transversal, analítico, descritiva e correlacional. Participaram 971 estudantes do ensino secundário público e cooperativo. O protocolo de avaliação inclui o questionário sociodemográfico, a Escala de Envolvimento com o Álcool para Adolescentes de Mayer & Filstead (1979) adaptada por Fonte & Alves (1999), o Questionário Reduzido de Auto-regulação (Carey, Neal & Collins, 2004 adaptado por Castillo & Dias, 2009), o Questionário de Expectativas face ao Álcool para Adolescentes (Pilatti, Godoy & Brussino, 2010), a Escala de Auto-Estima de Rosenberg (Romano, Negreiro & Martins, 2007), o Inventário Clínico do Autoconceito (Vaz Serra, 1984) e dados sociodemográficos, escolares e estilos de vida. Resultados: Os estudantes com idades compreendidas entre os 14 ­ 21 anos, na sua maioria rapazes (50,80%), com idade igual ou inferior a 16 anos (43,40%), residentes em meio rural (66,40%), em coabitação com os pais (77,30%) e inseridos em agregados familiares com um rendimento médio mensal médio alto ou alto (56,70%). Revelaram-se bebedores habituais sem problemas (75,30%), com elevadas expectativas face ao álcool (45,10%), boa auto-estima (47,40%) e com um bom autoconceito (45,30%). A autoregulação (total) foi influenciada pelo envolvimento com o álcool, expectativas face ao álcool, auto-estima negativa e duas das dimensões do autoconceito (maturidade psicológica e impulsividade/actividade). Conclusão: O desenvolvimento de competências de auto-regulação revela-se um investimento em saúde uma vez que, o adolescente com um comportamento auto-regulado assume estilos de vida mais saudáveis, revelando um menor envolvimento com o álcool.

Background: Adolescence is characterized by being a phase in the life cycle where the desire for experimentation and exploration of new sensations leads many teens to initiation of alcohol consumption, with adverse consequences for the health of the young. The behavior of self-regulated health includes control of most immediate needs (impulse control) and the mobilization of thoughts, feelings and behaviors for purposes of long-term health. Objectives: analyze the relation between sociodemographic variables, of school context, lifestyles, involvement and expectations towards alcohol and psychological variables (selfesteem and self-concept) with the powers of self-regulation in adolescents of secondary school in the district of Viseu. Methods: He turned to a quantitative research model, transversal, analytic, descriptive and correlational. 971 public and cooperative high school students participated. The evaluation protocol includes a sociodemographic questionnaire, the Alcohol Involvement Scale for Adolescents by Filstead & Mayer (1979) adapted by Fonte & Alves (1999), the Questionnaire of Reduced Self-regulation (Carey, Neal & Collins, 2004) adapted by Castillo & Dias (2009), the Questionnaire of Expectations in relation to Alcohol for Teens (Pilatti, Brussino & Godoy, 2010), Self-Esteem Scale of Rosenberg (Romano, Negreiro & Martins, 2007), Clinical Inventory of Self-concept (Vaz Serra, 1984), demographic data, school and lifestyles. Results: The students with ages between 14-21 years, mostly boys (50.80%), aged less than 16 years (43.40%), residents in rural areas (66.40%), cohabiting with parents (77, 30%) and placed in households with an average monthly income medium-high or high (56.70%). Proved to be habitual drinkers without problems (75.30%), with high expectations towards alcohol (45.10%), good self-esteem (47.40%) and with a good self-concept (45.30%). Selfregulation (total) was influenced by involvement with alcohol, expectations regarding alcohol, self-esteem and negative self-concept in two dimensions (psychological maturity and impulsivity/activity). Conclusion: The development of skills of self-regulation proves to be an investment in health since the teenager with a self-regulated behavior assumes healthier lifestyles, revealing a lower involvement with alcohol.