Development of Novel Photocatalytic Strategies and Visible Light Photocatalysts

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 20-04-2020Esta tesis tiene embargado el acceso al texto completo hasta el 20-10-2021La presente tesis ha sido realizada en el Departamento de Química Orgánica de la Universidad Autónoma de Madrid, bajo la supervisión del Prof. Dr. José Julián Alemán Lara. La financiación de este trabajo ha provenido del Consejo Europeo de Investigación (ERC-CG, número de contrato 647550), del Ministerio de Economía y Competitividad (CTQ-2015-64561-R y RTI2018-095038- B-I00), de la “Comunidad de Madrid” y de los Fondos Estructurales y de Inversión Europeos (S2018/NMT-4367

Does leader–member exchange buffer or intensify detrimental reactions to psychological contract breach? The role of employees' career orientation

There is an ongoing debate about two contradictory moderating effects of leader–member exchange (LMX) on the relationship between psychological contract breach (PCB) and work outcomes. Whereas some studies demonstrated LMX to be a social support resource capable of buffering the negative effects of PCB, findings from other research suggest that employees show stronger negative reactions to PCB when the quality of relationships with leaders is high. The present study addresses how these contradictory results can be explained by individuals' career orientations. We surveyed a representative random sample of 954 employees from various organizations and occupations to test whether employees with organization-centred versus self-centred career orientations show different interaction effects of PCB and LMX on (a) career satisfaction and (b) counterproductive work behaviour. The results confirmed our hypotheses, demonstrating that for employees with organization-centred career orientations (n = 596) high LMX fosters detrimental reactions to PCB, whereas for employees with self-centred career orientations (n = 358), high LMX functions as a buffer against negative reactions to PCB. Implications of a more nuanced understanding of how PCB and LMX interact are valuable for research and practice alike

Enantioselective Aminocatalytic [2 + 2] Cycloaddition through Visible Light Excitation

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: https://pubs.acs.org/doi/full/10.1021/acscatal.0c01413An asymmetric aminocatalytic activation strategy to obtain enantioenriched cyclobutanes through [2 + 2] photocycloaddition under visible light irradiation is presented. This metal-free process does not require the use of any external photocatalyst, as it is catalyzed by a simple diamine which, upon condensation with an enone substrate, forms an iminium ion intermediate that absorbs in the visible light region. The direct excitation of such an intermediate leads to a charge transfer (CT) excited state that unlocks a stereocontrolled intermolecular photocycloaddition with good enantiomeric and diastereoisomeric ratios and high yields. Finally, DFT calculations and experiments were performed to support the charge transfer behavior and the mechanistic proposalFinancial support was provided by the European Research Council (ERC-CoG, Contract No. 647550), the Spanish Government (RTI2018-095038–B-I00), “Comunidad de Madrid”, and European Structural Funds (S2018/NMT-4367

Nonlinear associations between breached obligations and employee well-being

Purpose – The purpose of this paper is to analyze the nonlinear association between proportions of breached obligations within the psychological contract (PC) and three dimensions of employee well-being, and the mediating role of contract violation in these relationships. With this study the authors gain a more detailed understanding of PC evaluations and their consequences for well-being. Design/methodology/approach – The authors build on asymmetry effects theory and affective events theory to propose that breached obligations outweigh fulfilled obligations in their association with well-being. The hypotheses are tested using a sample of 4,953 employees from six European countries and Israel. Findings – The results provide support for the hypotheses, as the effect sizes of the indirect relationships for breached obligations on well-being via violation are initially strong compared to fulfilled obligations, but decrease incrementally as the proportion of breached obligations become greater. At a certain point the effect sizes become nonsignificant. Research limitations/implications – The study shows that PC theory and research needs to better acknowledge the potential for asymmetrical effects of breach relative to fulfillment, such that the breach of obligations can sometimes have a stronger effect on employee well-being than the fulfillment of obligations. Practical implications – Those responsible for managing PCs in organizations should be aware of the asymmetrical effects of breach relative to fulfillment, as trusting on the acceptance or tolerance of employees in dealing with breached obligations may quickly result in lower well-being. Originality/value – The findings have implications for the understanding of PC breach and its associations with employee well-being

Leaders’ Gender, Perceived Abusive Supervision and Health

Purpose: We investigated the role of gender in abusive leadership practices, along with the effects of abusive leadership on employee health. We tested two hypotheses regarding the relationship between abusive leadership practices and subordinates’ health outcomes.Design: At two points of measurement, 663 participants in Germany rated their 158 direct team leaders on abusive supervision and stated their own levels of emotional exhaustion and somatic stress. To test our hypotheses, we used a mixed model approach.Findings: The results show no gender differences between the ratings for female and male leaders regarding abusive supervision but do confirm that the leaders’ gender did play a role in employees’ perceptions of abuse; perceived abusive supervision is more strongly related to increased emotional exhaustion and somatic stress when the leader is male.Limitations: The generalizability of the study is limited due to a majority of females in the sample.Practical Implications: Organizations should review their policies and procedures to first identify abusive supervision, then to offer adequate support programs for both leaders and subordinates.Originality/Value: The study integrates gender into research on leadership and health, shifting the focus from previous studies that investigated constructive to destructive leadership. A further strength of the study is the application of a multilevel design and two separate points of measurement

Threatening the Self: The Conditional Indirect Effect of Abusive Supervision on Well-Being

Occupational self-efficacy is a valuable resource for well-being and health in the workplace, but according to the stress-as-offense-to-self model, it can be threatened by abusive supervisors. In our study, we examined this mechanism through which abusive supervisors indirectly affect subordinates’ well-being. Assuming differences between male and female subordinates regarding occupational self-efficacy, we considered gendered responses to abusive supervision. We studied 928 participants, nested within 188 teams, who rated their self-efficacy and their direct supervisors’ leadership behaviour and who indicated work engagement and depressive symptoms at 2 time points with a lag of 6 months. Longitudinal relationships among the study variables were modelled using latent differences scores. Results showed that abusive supervision is indirectly related to work engagement and depressive symptoms regardless of gender

The Effect of Systematic Clinical Interventions with Cigarette Smokers on Quit Status and the Rates of Smoking-Related Primary Care Office Visits

Background: The United States Public Health Service (USPHS) Guideline for Treating Tobacco Use and Dependence includes ten key recommendations regarding the identification and the treatment of tobacco users seen in all health care settings. To our knowledge, the impact of system-wide brief interventions with cigarette smokers on smoking prevalence and health care utilization has not been examined using patient population-based data. Methods and Findings Data on clinical interventions with cigarette smokers were examined for primary care office visits of 104,639 patients at 17 Harvard Vanguard Medical Associates (HVMA) sites. An operational definition of “systems change” was developed. It included thresholds for intervention frequency and sustainability. Twelve sites met the criteria. Five did not. Decreases in self-reported smoking prevalence were 40% greater at sites that achieved systems change (13.6% vs. 9.7%, p<.01). On average, the likelihood of quitting increased by 2.6% (p<0.05, 95% CI: 0.1%–4.6%) per occurrence of brief intervention. For patients with a recent history of current smoking whose home site experienced systems change, the likelihood of an office visit for smoking-related diagnoses decreased by 4.3% on an annualized basis after systems change occurred (p<0.05, 95% CI: 0.5%–8.1%). There was no change in the likelihood of an office visit for smoking-related diagnoses following systems change among non-smokers. Conclusions: The clinical practice data from HVMA suggest that a systems approach can lead to significant reductions in smoking prevalence and the rate of office visits for smoking-related diseases. Most comprehensive tobacco intervention strategies focus on the provider or the tobacco user, but these results argue that health systems should be included as an integral component of a comprehensive tobacco intervention strategy. The HVMA results also give us an indication of the potential health impacts when meaningful use core tobacco measures are widely adopted

Asymmetric [2+2] photocycloadditionviacharge transfer complex for the synthesis of tricyclic chiral ethers

The asymmetric synthesis of chiral polycyclic ethers by an intramolecular [2+2] photocycloaddition is described. This process proceeded through a photocatalytically active iminium ion-based charge transfer (CT) complex under visible light irradiation. In this way a stereocontrolled [2+2] photocycloaddition is enabled leading to tricyclic products with good enantiomeric ratiosFinancial support was provided by the European Research Council (ERC-CoG, Contract No. 647550), the Spanish Government (RTI2018-095038-B-I00, PID2019-110091GB-I00), ‘‘Comunidad de Madrid’’, and European Structural Funds (S2018/NMT-4367

A bifunctional photoaminocatalyst for the alkylation of aldehydes: Design, analysis, and mechanistic studies

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright ©2018 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acscatal.8b01331A bifunctional photoaminocatalyst based on imidazolidinone and thioxanthone is presented. The preparation of these catalysts proceeds in a two-step synthesis that allows an easy tuning of the steric properties. The photophysical and electrochemical data of the imidazolidinone photocatalysts have been determined, indicating that the catalysts can work under visible light conditions. To corroborate the experimental observations, ground state geometry optimization and energy transition studies of thioxanthone and bifunctional catalyst 4c were optimized by time-dependent density functional theory (TD DFT) calculations. The alkylation of aldehydes with this photoaminocatalyst works with high enantioselectivities and yields due to the stereoelectronic properties of the catalyst. A rational mechanistic cycle based on different mechanistic experiments, TD DFT calculations, and laser flash photolysis is presentedThe Spanish Government (CTQ2015-64561-R) and the European Research Council (ERC-CG, Contract 647550) are acknowledge