High Turnover Research Articles

N, N’-bidentate ligand anchored palladium catalysts on MOFs for efficient Heck reaction

Metal-organic frameworks (MOFs), recognized as advanced catalyst carriers due to their adjustable porous, diverse structure and highly exposed active sites, have earned increasing attention for their potential to address the longevity of catalytic centers. In this manuscript, we have devised and synthesized a multifunctional amino-pyridine benzoic acid (APBA) ligand to replace the modulator ligand of the MOF-808 and disperse the palladium catalytic centers atomically on the MOF-APBA. The resulting single-site catalytic system, Pd@MOF-APBA, demonstrates preeminent efficiency and stability, as evidenced by a high average turnover number (95000) and a low metal residue (4.8 ppm) in the Heck reaction. This catalyst has exhibited recyclability for multiple runs without significant loss of reactivity for gram-scale reactions. The catalyst’s high activity and efficiency can be attributed to the suitable electrical properties and structures of the N, N’-bidentate ligand for the catalytic palladium ions, postponing their deactivations, including leaching and agglomeration.

Trust, respect, and training: Principles of care for service professionals supporting adults with intellectual disabilities in community residential programs.

Background: Adults with intellectual disabilities in community residential programs receive services from direct support professionals (DSPs) intended to facilitate community engagement. As part of a rate study for Washington State's Developmental Disabilities Administration on community residential services, adults in these programs were asked to provide their perspective on the quality and effectiveness of their care.Method: Twenty-five adults with intellectual disabilities were interviewed focusing on daily activities, staffing, and living situations. Interview transcripts were coded and analyzed for dominant themes.Results: Participants emphasized the desire for trustworthy, caring, and respectful DSPs; DSPs trained in behavioral management techniques made participants feel safe and supported. Nearly all participants called for greater staffing stability.Conclusions: People living in community residential programs are profoundly impacted by the stress and uncertainty of DSPs facing limited resources and high staff turnover. Stable, consistent support makes it easier for participants to engage in community integration.

Identification of implementation enhancement strategies for national comprehensive care standards using the CFIR-ERIC approach: a qualitative study

BackgroundComprehensive care is important for ensuring patients receive coordinated delivery of healthcare that aligns with their needs and preferences. While comprehensive care programs are recognised as beneficial, optimal implementation strategies in the real world remain unclear. This study utilises existing implementation theory to investigate barriers and enablers to implementing the Australian National Safety and Quality Health Service Standard 5 - Comprehensive Care Standard in acute care hospitals. The aim is to develop implementation enhancement strategies for work with comprehensive care standards in acute care.MethodsFree text data from 256 survey participants, who were care professionals working in acute care hospitals across Australia, were coded using the Consolidated Framework for Implementation Research (CFIR) using deductive content analysis. Codes were then converted to barrier and enabler statements and themes using inductive theme analysis approach. Subsequently, CFIR barriers and enablers were mapped to the Expert Recommendations for Implementing Change (ERIC) using the CFIR-ERIC Matching Tool, facilitating the development of implementation enhancement strategies.ResultsTwelve (n = 12) CFIR barriers and 10 enablers were identified, with 14 barrier statements condensed into 12 themes and 11 enabler statements streamlined into 10 themes. Common themes of barriers include impact of COVID-19 pandemic; heavy workload; staff shortage, lack of skilled staff and high staff turnover; poorly integrated documentation system; staff lacking availability, capability, and motivation; lack of resources; lack of education and training; culture of nursing dependency; competing priorities; absence of tailored straties; insufficient planning and adjustment; and lack of multidisciplinary collaboration. Common themes of enablers include leadership from CCS committees and working groups; integrated documentation systems; established communication channels; access to education, training and information; available resources; culture of patient-centeredness; consumer representation on committees and working groups; engaging consumers in implementation and in care planning and delivery; implementing changes incrementally with a well-defined plan; and regularly collecting and discussing feedback. Following the mapping of CFIR enablers and barriers to the ERIC tool, 15 enhancement strategies were identified.ConclusionThis study identified barriers, enablers, and recommended strategies associated with implementing a national standard for comprehensive care in Australian acute care hospitals. Understanding and addressing these challenges and strategies is not only crucial for the Australian healthcare landscape but also holds significance for the broader international community that is striving to advance comprehensive care.

Patterns of health workforce turnover and retention in Aboriginal Community Controlled Health Services in remote communities of the Northern Territory and Western Australia, 2017–2019

BackgroundAboriginal Community Controlled Health Services (ACCHSs) in Australia aim to optimise access to comprehensive and culturally safe primary health care (PHC) for Aboriginal populations. Central to quality service provision is the retention of staff. However, there is lack of published research reporting patterns of staff turnover and retention specific to ACCHSs. This study quantified staff turnover and retention in regional and remote ACCHSs in the Northern Territory (NT) and Western Australia (WA), and examined correlations between turnover and retention metrics, and ACCHSs’ geographical and demographic characteristics.MethodsThe study used 2017–2019 payroll data for health workers in 22 regional and remote PHC clinics managed by 11 ACCHSs. Primary outcome measures included annual turnover and 12-month stability rates, calculated at both clinic and organisation levels.ResultsThere was a median of five client-facing (Aboriginal health practitioners, allied health professionals, doctors, nurses/midwives, and ‘other health workers’ combined) and two non-client-facing (administrative and physical) staff per remote clinic, at any timepoint. Mean annual turnover rates for staff were very high, with 151% turnover rates at the clinic level and 81% turnover rates at the organisation level. Mean annual turnover rates for client-facing staff were 164% and 75%, compared to 120% and 98% for non-client-facing staff, at clinic and organisational levels, respectively. Mean 12-month stability rates were low, with clinic-level stability rates of only 49% and organisation-level stability rates of 58%. Mean annual clinic-level turnover rates were 162% for non-Aboriginal staff and 81% for Aboriginal staff. Both workforce metrics were moderately to highly correlated with the relative remoteness of clinics, size of regular clients serviced, and average annual headcount of employees in each clinic (p values < 0.01).ConclusionsParticipating ACCHSs in remote NT and WA have very high turnover and low retention of healthcare staff. Overall, clinic-level turnover rates increase as distance from regional centres increases and are lower for Aboriginal staff, suggesting that greater employment of Aboriginal staff could help stabilise staffing. Improved retention could reduce burden on ACCHSs’ resources and may also support quality of service delivery due to improved cultural safety and continuity of care.

Pengaruh Job Insecurity dan Work Stress Terhadap Turnover Intention dengan Job Satisfaction Sebagai Variabel Mediasi: Studi pada Karyawan Kantor PT Semarang Garment

Turnover Intention is a person's desire to leave their current job to get a better job than their previous workplace High turnover rate can result in problems for the company. The purpose of this study is to determine the effect of Job Insecurity and Work Stress on Turnover Intention with Job Satisfaction as a Mediation Variable at PT Garment Semarang. This study was conducted at PT Garment Semarang, with a sample taken as many as 50 people using the saturated sample method, where this saturated sample method used the entire population as respondents in the study. Data collection was carried out by distributing questionnaires using a Likert scale. The results of the study show that there is a positive influence of job insecurity on turnover intention. There is a positive influence of work stress on turnover intention There is a negative influence on job insecurity on job satisfaction. There is an influence of work stress on job satisfaction. There is an influence of job satisfaction on turnover intention. There is an effect of job insecurity on turnover intention mediated by job satisfaction. There is an effect of work stress on turnover intention mediated by job satisfaction. . Employees who have feelings of insecurity at their jobs and feel high work stress do not directly have the intention to leave the company. This is because one of the most important factors that affect the decision is work performance. This study is expected to be a reference and supporting evidence regarding the influence of each variable discussed in this study. Keywords: Job Insecurity; Work Stress ; Turnover Intention; Job Satisfaction

Architecture of bimodal porous CuO/Al2O3-controlled continuous and low-temperature production of biomass-derived γ-butyrolactone

Biomedical activities of gamma butyrolactone (GBL) play an important role in the development of novel physiological and therapeutic agents. Maleic anhydride catalytic liquid phase hydrogenation allows for selective synthesis of GBL. However, this process is hampered by high cost noble metals and high reaction pressure conditions. Here, we demonstrate cyclic dehydrogenation of biomass-derived 1,4-butanediol (1,4-BDO) under atmospheric pressure and low-temperature conditions using highly dispersed and chemically stabilized Cu species on bimodal porous Al2O3. The bimodal porous Al2O3 exhibited both Lewis and Brønsted acidic properties along with high specific surface area and large pore volume. Among prepared catalysts, 15 wt% Cu/Al2O3 catalyst has shown an optimal crystallite size, bimodal porous nature, and high diffusion properties. Hence, high catalytic activity and remarkable GBL yields with very high 1,4-BDO conversion for 50 h of continuous time-on-stream. The unique bimodal textural properties help to enhance the dehydrogenation activity with a high turnover frequency (TOF) of about 5.0118 x 10-3 s-1via efficient chemical interaction between metallic Cu and 1,4-BDO molecules.

Construction of N-Fe-S bridge in atomic iron catalyst for boosting Fenton-like reactions

Constructing the coordination environment of single-atom catalysts (SACs) can be an attractive technical strategy to regulate the generation of reactive oxygen species for Fenton-like reactions. Herein, we have constructed an asymmetric coordination of Fe single-atom catalyst (FeSA-NS-PCNS) with abundant N-Fe-S bridge (FeSA-N3S1) for robust Fenton-like reactions. 82.5 % of singlet oxygen (1O2) selectivity and high turnover frequency of bisphenol A degradation (0.568 min−1) were achieved at mild conditions. Experimental works and theoretical analyses illustrated that S doping breaks the inert environment of the original N-Fe-N symmetric coordination equilibrium and modulates the electron density of the atomic Fe center, which is beneficial for boosting PMS adsorption and reducing the energy barriers of vital *OH and *O intermediates. The coupling between the FeSA-N3S1 interface and peroxymonosulfate molecule boosts in-situ electron transfer through the N-Fe-S bridge, which induces more electron flow from the low valence Fe to OH* on the surface of Fe-*O-H, forming a high yield of 1O2. Moreover, we designed the Fenton-like reactions by FeSA-NS-PCNS membrane reactor for an efficient contaminant removal rate of over 90 % even after 11 cycles. This work provides a novel perspective on developing SACs with asymmetric coordination to regulate reactive oxygen species for the treatment of organic contaminants in water bodies.

COVID-19 infection prevention and control program for aged care providers: a quasi-experimental study of Telegram-based training

ABSTRACT Given the high turnover of care workers in residential aged care facilities, continuous training on infection prevention and control (IPC) remains essential even after the COVID-19 pandemic. This study examined the impact of a Telegram-based training on aged care providers’ IPC knowledge, attitudes, self-efficacy. A two-arm, pre-post quasi-experimental study with repeated measures at week 2 (T1) and week 4 (T2) was conducted for seventy-two (72) participants from 14 residential aged care facilities in Malaysia, with 60 completing the study (30 per arm). All instructional activities and data collection for both groups were delivered through Telegram. The intervention group received a 2-day synchronous workshop (3 h/day) alongside e-materials for a 10-unit IPC module. Primary outcomes were measured using a knowledge test, COVID-19 Elderly Caregiver Questionnaire (attitude component), and an adapted General Self-Efficacy Scale. Telegram’s acceptability was also assessed using an adapted Technology Acceptance Model questionnaire. Results showed that the intervention group had a faster knowledge transfer (91.3%–93.5%; T0-T2 = ∆22.9; p ≤ .002;), higher knowledge scores (∆7.2–16; p ≤ .002; large effect sizes 0.9–1.7), and a small-to-modest increments in self-efficacy (∆13.2; p = .002) and attitude (∆5.2; p = .045). Integrating synchronous sessions into an online program improved knowledge transfer, enhanced self-efficacy and promoted positive attitudes by enabling real-time interpersonal communication and instant feedback. Telegram proved effective for mobile learning in aged care settings with limited resources.

The Value of ETF Liquidity

Abstract We analyze how ETFs compete. Drawing on a new model and empirical analysis, we show that ETF secondary market liquidity plays a key role in determining fees. More liquid ETFs for a given index charge higher fees and attract short-horizon investors who are more sensitive to liquidity than to fees. Higher turnover from these investors sustains the ETF’s high liquidity, allowing the ETF to extract a rent through its fee, and creating a first-mover advantage. Liquidity segmentation through clientele effects generates welfare losses. Our findings resolve the apparent paradox that higher-fee ETFs not only survive but also flourish in equilibrium.

Production of Lactic Acid via Catalytic Transfer Dehydrogenation of Glycerol Catalyzed by Base Metal Salt Ferrous Chloride and Its NNN Pincer-Iron Complexes.

NNN-Bis(imino) pyridine-based pincer-Fe(II) complexes with an expected trigonal bipyramidal (TBP) geometry equilibrated to a rearranged ion pair of an octahedral dicationic Fe complex containing two bis(imino)pyridine ligands that are neutralized by a tetrahedral dianionic-[FeCl4]2-. Single-crystal X-ray diffraction (SCXRD), high-resolution mass spectrometry (HRMS), and UV-visible (UV-vis) studies suggested that the equilibrium was dictated by the sterics of the R group on the imine N, with the less-crowded groups tilting the equilibrium to the ion pair and the bulky ones favoring the TBP geometry. Electron paramagnetic resonance (EPR) and Evan's magnetic moment measurements indicated that the complexes were paramagnetic with Fe(II) in a high-spin state. In solution, over a period of 7 days, these Fe(II) complexes oxidized to a mixture of low-spin and high-spin Fe(III) species. These pincer-Fe(II) were found to be highly active toward the transformation of biodiesel waste glycerol to value-added lactic acid (LA). Particularly, (Ph2NNN)FeCl2 (0.1 mol %) gave 91% LA with a 99% selectivity at 140 °C using 1.2 equiv of NaOH. With 0.0001 mol % (Ph2NNN)FeCl2, very high turnovers (74% LA, 98% selectivity, 740 000 turnover number (TON) at 4405 turnovers per hour (TOs/h)) were obtained after 7 days. EPR indicated Fe(III) species to be the active catalyst, a few of which were detected by HRMS. Experiments with Hg are suggestive of the mostly homogeneous molecular nature of the catalyst with a minor contribution from heterogeneous Fe nanoparticles.

Exploring and Improving the Potential Factors of Preschool Teacher Resignation Using the Stratified Bayesian Best-Worst Method

The high turnover rate of preschool teachers in the educational sector threatens the ability to retain competent teaching staff and affects the quality of teaching and the development of early education in many countries. These ramifications are especially poignant given their alignment with the United Nations’ sustainable development goals (SDGs) - notably “quality education,” “good health and well-being,” and “decent work and economic growth.” Reducing the turnover rate of educators, especially at the preschool level, has become an urgent issue for the education community. Therefore, this paper develops a multiple criteria decision-making (MCDM) model based on expert knowledge to construct an evaluation model of the main factors for the resignation of preschool teachers. These factors comprise three main dimensions: personal factors, internal organizational culture, and external environment. First, potential resignation factors were identified through a literature survey and interviews with several experts. Then, a stratified Bayesian best-worst method (SB-BWM) was used to evaluate the importance of these potential factors. The method generated the optimal group weights of the resignation factors and ranked them. The results of this study reveal that the top five resignation factors are high work stress, work-induced emotional exhaustion/job burnout, poor work atmosphere, high workload, and low collaborative relationships with partners. The results can help preschool education operators and education ministries responsible for decision-making to understand the factors leading to the resignation of preschool teachers so that they can develop strategies to improve retention. Management implications are given to improve operational performance and effectively reduce the teacher turnover rate to promote stability in the learning environment so important to early childhood development, which will lead to quality preschool education development.

Reducing turnover intentions of Black employees in the accounting profession: The roles of racial centrality, racial identity affirmation and supervisor closeness

Within the accounting profession, a persistent organizational issue is higher turnover rates among Black employees compared to White employees. Yet, there is currently no clear theoretical understanding of the reasons behind this higher turnover and how to reduce it. Drawing from focus groups of Black certified public accountants and in-depth interviews with both Black accountants and White supervisors of Black accountants, we developed a theoretical framework highlighting crucial psychological, behavioral, and relational factors that we predict are associated with reduced turnover intentions by Black employees. We propose that Black employees' racial centrality is associated with racial identity affirmation—attempts to affirm one's racial identity by expressing and highlighting positive aspects of one's racial group. Furthermore, we posit that the relationship between racial identity affirmation and reduced turnover intentions is weaker for Black accountants who feel less close to their supervisors, as their affirmations are less likely to be validated. We tested these hypotheses using a sample of 222 Black accountants, and our findings supported our predictions. We discuss the implications of these findings for theory, practice, and future research.

Exploring Perspectives on Stroke Standard Set Data Collection: A Qualitative Descriptive Study.

BACKGROUND: The International Consortium on Health Outcome Measurement developed a standard set for stroke (SSS) that includes patient-reported outcome measures to help capture patients' perspectives on their poststroke recovery. The objective of this study was to explore the experiences and perspectives of individuals who collected SSS data from patients who were admitted to hospital for a stroke. METHODS: A qualitative descriptive approach was taken. Semistructured, audio-recorded interviews were conducted with individuals employed at 2 acute neurological inpatient units in Southwestern Ontario, Canada. Interviews were transcribed verbatim and written text responses were analyzed directly. Transcripts were coded line by line and then organized into 5 overarching themes: adoption, acceptance, appropriateness, feasibility, and sustainability. RESULTS: Six interviews were conducted with participants from varying roles (eg, nurses, manager, web developer, social worker, medical clerk). Participants reported that patients were receptive to completing the SSS. Follow-up phone calls provided a significant opportunity to monitor patients' recovery postdischarge. Many patients requested medical guidance and help navigating health and social resources for unmet stroke-related needs. Barriers to consistent SSS assessment included high employee turnover and lack of time, space, or capacity for follow-up. To sustain data collection, a dedicated, financially supported neurological nursing role was suggested. CONCLUSION: Participants were supportive of SSS data collection that could provide monitoring, oversight, and follow-up of stroke patients after discharge from acute care. However, the utility of the dataset is heavily dependent on having the data collection process properly resourced.

Implementation of Knowledge Management at PT Multi Phi Beta to Prevent Knowledge Loss

PT Multi Phi Beta, as an engineering consultancy, faces challenges in a competitive industry that demands operational efficiency. The company encounters high employee turnover due to the short-term nature of its projects, leading to a significant risk of knowledge loss. This research aims to evaluate the current state of knowledge management readiness at PT Multi Phi Beta, identify gaps in knowledge management implementation, and propose improvements to mitigate these knowledge loss risks and enhance overall efficiency. The primary method used to obtain data is quantitative, collected through questionnaires. To enrich the primary data, qualitative data is gathered through semi-structured interviews. The findings indicate that PT Multi Phi Beta is at the initiation level of KM readiness, recognizing the need for knowledge management but not yet fully integrating KM practices. To mitigate knowledge loss, the company should capture critical knowledge from transitioning employees, enhance its KM vision and mission, and establish a dedicated KM department. Standardized processes for managing knowledge, conducting after-action reviews, knowledge cafés, and formal mentoring programs are essential. Additionally, providing integrated knowledge repositories and implementing a rewards and recognition program will encourage knowledge sharing and strengthen the company’s KM efforts.

Rocky outcrops form islands of high and unique tree biodiversity within an ocean of grass in Serengeti National Park

AbstractAfrican savannahs are characterised by a high plant diversity, partly resulting from a high turnover in community compositions across space. However, it is poorly understood what is driving this spatial turnover in plant communities. Here, we investigate to which extent the presence of rocky outcrops (also called kopjes) explains the community composition of trees in an African savannah, and how we can understand the responses of tree species to rocky outcrops by their functional traits. Along a precipitation gradient, we visited 24 sites in Serengeti National Park (Tanzania). At each site, we characterised tree communities, as well as their functional traits, in both a kopje and an adjacent open savannah plot (matrix plot). We found that kopjes harboured elevated tree abundances and species richness. Their dominant trees were more often evergreen, had a higher specific leaf area, a lower leaf nitrogen content and a lower spine density, than dominant trees in the savannah matrix. Differences in tree communities between kopjes and savannah matrix plots were generally the largest at sites with low precipitation. Our results indicate that kopjes are strong drivers of tree biodiversity, possibly due to locally increased soil moisture and low fire frequencies. The uniqueness of kopje tree communities may have important implications for higher trophic levels and ecosystem functioning.

The childcare director’s role in preventing burnout: a positive-psychological examination of the caregivers’ lived experience

ABSTRACT This study applied a positive-psychological approach to examining childcare directors’ role in maintaining the stability of their staff from the caregivers’ and directors’ points of view. Most of the childcare centers in Israel are characterized by high burnout and turnover of staff members. Nevertheless, some teams stay stable, and turnover is minimal. This study explored the factors using 30 semi-structured interviews with childcare center directors and caregivers regarding their occupational stability. Findings suggested that the sense of belonging to the childcare center was one source of stability. The director acted as a safe haven, maintaining the caregivers’ wellbeing. Other success factors are related mainly to their relations with other staff members, with the director, and with the children, and also to proper management that provides professional training and treats them with respect. The study’s contribution is fourfold. First, it gives voice to a population of women who work under difficult conditions for low pay. Second, it highlights the role of the childcare director in maintaining staff stability. Third, implementing its findings is relevant to creating and improving models of training and supervising early childhood educators. Fourth, studying anti-burnout factors can strengthen teams and provide the children with positive relationships with significant others.

Variations in source-specific soil organic matter components across 32 forest sites in China

Forest soils store substantial amounts of carbon in various soil organic matter (SOM) components due to high plant litter inputs and active microbial turnover. However, the variations in plant- and microbial-derived SOM components in surface and subsurface forest soils across a wide geographic scale remain poorly understood. This study investigated the SOM components from aboveground and belowground plant inputs and fungal and bacterial necromass in surface (soil0–5 cm) and subsurface (soil5–10 cm) soils across 32 forest sites in China and analyzed their relationships with climate and edaphic factors. Compared to soil0–5 cm, soil5–10 cm exhibited lower soil organic carbon content and cutin biomarker concentration but higher concentrations of fungal necromass carbon and lignin phenols. Higher mean annual precipitation led to higher concentrations of cutin and suberin biomarkers in soil0–5 cm and soil5–10 cm, respectively. Higher soil organic carbon content was associated with lower plant-derived lignin biomarkers, higher lignin oxidation degrees, and increased microbial necromass-derived amino sugars across sites, highlighting the pivotal role of microbial necromass in SOM stabilization. Additionally, both fungal and bacterial necromass decreased with increasing mineral weathering across sites. These insights improve the understanding of environmental drivers of source-specific carbon storage in forest soils.Graphical

Who is suited to work in remote First Nations health? Perspectives of staff in remote Aboriginal Community-Controlled Health Services in northern Australia.

There is a shortage of nurses, Aboriginal Health Practitioners, GPs and other staff in remote Australian health clinics. There is also high turnover of staff, leading to questions of 'who' is appropriate for remote First Nations practice? The aim of this paper was to identify the characteristics of staff who are likely to work well in remote First Nations settings, from the perspectives of remote health practitioners. This is a qualitative study involving content analysis of interviews. The study is conducted in and with 11 Aboriginal Community Controlled Health Services across northern and central Australia. Eighty-four staff working in these clinics who spoke about staff qualities suited to remote practice. Participants identified a range of qualities desirable in remote practitioners, which were grouped into three topics: (1) professional qualifications and experience, including cultural skills; (2) ways of working, including holisitic approach, resilience, competence, and being a team player, approachable, flexible and hard-working; and (3) specific community needs, namely the need for local First Nations staff, male practitioners and returning short-term staff. The combination of experiences, ways of working, and fit to both the team and community were emphasised. Identifying the characteristics of staff who are likely to work well in these settings can inform recruitment strategies. This study found that a combination of professional qualifications, skills and experience as well as ways of working, individual characteristics and needs of communities are desirable for working in remote, First Nations settings.

Zwitterionic Acridinium Amidate: A Nitrogen‐Centered Radical Catalyst for Photoinduced Direct Hydrogen Atom Transfer

AbstractThe development of small organic molecules that can convert light energy into chemical energy to directly promote molecular transformation is of fundamental importance in chemical science. Herein, we report a zwitterionic acridinium amidate as a catalyst for the direct functionalization of aliphatic C−H bonds. This organic zwitterion absorbs visible light to generate the corresponding amidyl radical in the form of excited‐state triplet diradical with prominent reactivity for hydrogen atom transfer to facilitate C−H alkylation with a high turnover number. The experimental and theoretical investigations revealed that the noncovalent interactions between the anionic amidate nitrogen and a pertinent hydrogen‐bond donor, such as hexafluoroisopropanol, are crucial for ensuring the efficient generation of catalytically active species, thereby fully eliciting the distinct reactivity of the acridinium amidate as a photoinduced direct hydrogen atom transfer catalyst.

Zwitterionic Acridinium Amidate: A Nitrogen-Centered Radical Catalyst for Photoinduced Direct Hydrogen Atom Transfer.

The development of small organic molecules that can convert light energy into chemical energy to directly promote molecular transformation is of fundamental importance in chemical science. Herein, we report a zwitterionic acridinium amidate as a catalyst for the direct functionalization of aliphatic C-H bonds. This organic zwitterion absorbs visible light to generate the corresponding amidyl radical in the form of excited-state triplet diradical with prominent reactivity for hydrogen atom transfer to facilitate C-H alkylation with a high turnover number. The experimental and theoretical investigations revealed that the noncovalent interactions between the anionic amidate nitrogen and a pertinent hydrogen-bond donor, such as hexafluoroisopropanol, are crucial for ensuring the efficient generation of catalytically active species, thereby fully eliciting the distinct reactivity of the acridinium amidate as a photoinduced direct hydrogen atom transfer catalyst.