A lonely electron blocks incoming pairs.
Ontology highlight
ABSTRACT:
SUBMITTER: Massari M
PROVIDER: S-EPMC7948957 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Polymeric frustrated Lewis pairs, or poly(FLP)s, have served to bridge the gap between functional polymer science and main group catalysis, pairing the uniqueness of sterically frustrated Lewis acids and bases with a polymer scaffold to create self-healing gels and recyclable catalysts. However, their utilization in radical chemistry is unprecedented. In this paper, we disclose the synthesis of polymeric frustrated radical pairs, or poly(FRP)s, by in situ photoinduction of FLP moieties, where their Lewis acidic and basic centers are tuned to promote single electron transfer (SET). Through systematic manipulation of the chemical structure, we demonstrate that inclusion of ortho-methyl groups on phosphine monomers is crucial to enable SET. The generation of radicals is evidenced by monitoring the stable polymeric phosphine radical cations via UV/vis and EPR spectroscopy. These new poly(FRP)s enable both catalytic hydrogenation and radical-mediated photocatalytic perfluoroalkylations. These polymeric radical systems open new avenues to design novel functional polymers for catalysis and photoelectrical chemistry.
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Project description:BACKGROUND:Loneliness in later life is largely presented as a problem of the individual focusing upon antecedents such as demographic or health factors. Research examining the role of the broader living environments is much rarer. We examined the relationship between loneliness and three dimensions of the lived environment: geographical region, deprivation, and area classification (urban or rural). METHODS:Our sample consisted of 4663 core members (44% males) aged 50+ (wave 7 mean age 72.8, S.D.?=?7.1) present both in waves 3 (2006) and 7 (2014) of the English Longitudinal Study of Ageing (ELSA). Loneliness was measured using two approaches, individual and area-based, and both waves included these questions. Individual-based (self-reported) loneliness was assessed using the three item University of California Los Angeles (UCLA) scale (ranging from 3?=?not lonely to 9?=?lonely) with a score of 6+ defining loneliness. We also used a novel question which asked participants to evaluate how often they felt lonely in their area of residence (area-based; ranging from 1?=?often to 7?=?never, using cut off 4+ to define loneliness). The lived environment was classified in three different ways: the Index of Multiple Deprivation (IMD), Government Office Regions (GOR), and area classification (urban or rural). Covariates with established relationship with loneliness including demographic factors, social engagement and health, were included in the analyses. RESULTS:In wave 7, the prevalence of individual-based loneliness was 18% and area-based was 25%. There was limited congruence between measures: 68% participants reported no individual- or area-based loneliness and 9% reported loneliness for both measures. After adjusting for individual co-variates only one significant relationship was observed between loneliness and area -based characteristics. A significant association was observed between area-based loneliness and deprivation score, with higher levels of loneliness in more deprived areas (OR?=?1.4 for highest quintile of deprivation). CONCLUSIONS:Our results indicate that loneliness in older adults is higher in the most deprived areas independent of individual-level factors. In order to develop appropriate interventions further research is required to investigate how area-level factors combine with individual-level loneliness vulnerability measures to generate increased levels of loneliness in deprived areas.
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