Family Of Complexes Research Articles

Extensions of the category of comodules of the Taft algebra

We construct a family of non-equivalent pairwise extensions of the category of comodules of the Taft algebra, which are equivalent to representation categories of non-triangular quasi-Hopf algebras.

A Study on Work-Life Quality of Female Domestic Workers

Abstract: Domestic workers are regarded as an important source of income for millions of women worldwide. This sector has existed for centuries, as evidenced by the histories of slavery, colonialism, and other forms of servitude. In today's society, the contribution of domestic work is vital for the economy. They have become increasingly in demand around the world in recent decades. Domestic workers are not normally considered workers, and their working conditions remain unregulated. Their employment situation is considered outside the general framework of existing employment laws. This is mainly because most of the work done is generally invisible. Women domestic workers account for a large part of India's unorganized labor force. Though men do this type of work, there is a trend toward the feminization of domestic work. People from lower socioeconomic backgrounds are primarily involved in this work. The increase in the number of domestic workers in India is attributed to an increase in affluent sections' per capita income, increased female labor participation, the disintegration of joint families, and an increase in life expectancy with an increase in ill health levels. Therefore, their daily struggle for survival has yet to capture the attention of the government. Thus, this study is entitled “A Study on Work-Life Quality of Female Domestic Workers.” This helps to understand the major factors responsible for the low economic status of women domestic workers. The study will also highlight the issues and problems of these women domestic workers and various measures that can be taken for the welfare of this sector. Key Words: Quality of Work Life, Women, and Domestic Workers.

Modelling the Binding of Cytotoxic Dinuclear Copper Complexes to two Neighboring Phosphate Esters of DNA Using Glutarate: A Tetranuclear Metallo‐Macrocycle vs a Dinuclear Model

AbstractA family of dinuclear complexes was rationally designed to bind to two neighboring phosphate diesters of DNA by molecular recognition. Although these complexes bind strongly and irreversibly to DNA and induce apoptosis in cancer cells, a direct proof of the intended binding mode is missing. To mimic two neighboring phosphate diesters of DNA, we use here the dicarboxylate glutarate as a difunctional ligand. Starting from the acetate‐bound CuII2 complex, protonation results in the de‐coordination of acetate and allows the synthesis of the glutarate‐bound complex. Instead of bridging two CuII ions of one dinuclear complex, two glutarates bridge two dinuclear complexes resulting in a tetranuclear metallo‐macrocycle. The molecular structures of two different salts differ in the square‐pyramidal coordination to the CuII ions. The carboxylate stretching modes, the d‐d and the CT transtitions are not sensitive enough to resolve these differences. The exchange coupling is weakly antiferromagnetic between the CuII ions in the dinuclear subunits and negligible between the subunits via the glutarates. The consequences for suited ligands to model the binding to two neighboring phosphate diesters in the DNA backbone is discussed.

La transmisión transgeneracional de situaciones traumáticas: papel de la psicología en el proceso de recuperación de la memoria colectiva de la dictadura franquista en España

In this work, some considerations are made about memory and forgetting, complex individual and family emotional processes that give rise to certain collective psychological states that are usually configured under dictatorships and totalitarian states are described. These reflections are framed in the context of Spain's recent history and will help to understand, at least in part, the enormous delay that the recovery of memory has had in our country. These contributions are supported by historical, sociological, and literary sources and based on psychological theory and clinical practice applied to individual, family, and group treatments.

Role of MCP-1 as an inflammatory biomarker in nephropathy.

The Monocyte chemoattractant protein-1 (MCP-1), also referred to as chemokine ligand 2 (CCL2), belongs to the extensive chemokine family and serves as a crucial mediator of innate immunity and tissue inflammation. It has a notable impact on inflammatory conditions affecting the kidneys. Upon binding to its receptor, MCP-1 can induce lymphocytes and NK cells' homing, migration, activation, differentiation, and development while promoting monocytes' and macrophages' infiltration, thereby facilitating kidney disease-related inflammation. As a biomarker for kidney disease, MCP-1 has made notable advancements in primary kidney diseases such as crescentic glomerulonephritis, chronic glomerulonephritis, primary glomerulopathy, idiopathic proteinuria glomerulopathy, acute kidney injury; secondary kidney diseases like diabetic nephropathy and lupus nephritis; hereditary kidney diseases including autosomal dominant polycystic kidney disease and sickle cell kidney disease. MCP-1 not only predicts the occurrence, progression, prognosis of the disease but is also closely associated with the severity and stage of nephropathy. When renal tissue is stimulated or experiences significant damage, the expression of MCP-1 increases, demonstrating a direct correlation with the severity of renal injury.

SIRAH Late Harvest: Coarse-Grained Models for Protein Glycosylation.

Glycans constitute one of the most complex families of biological molecules. Despite their crucial role in a plethora of biological processes, they remain largely uncharacterized because of their high complexity. Their intrinsic flexibility and the vast variability associated with the many combination possibilities have hampered their experimental determination. Although theoretical methods have proven to be a valid alternative to the study of glycans, the large size associated with polysaccharides, proteoglycans, and glycolipids poses significant challenges to a fully atomistic description of biologically relevant glycoconjugates. On the other hand, the exquisite dependence on hydrogen bonds to determine glycans' structure makes the development of simplified or coarse-grained (CG) representations extremely challenging. This is particularly the case when glycan representations are expected to be compatible with CG force fields that include several molecular types. We introduce a CG representation able to simulate a wide variety of polysaccharides and common glycosylation motifs in proteins, which is fully compatible with the CG SIRAH force field. Examples of application to N-glycosylated proteins, including antibody recognition and calcium-mediated glycan-protein interactions, highlight the versatility of the enlarged set of CG molecules provided by SIRAH.

Genome-wide analysis of the ABC gene family in almond and functional predictions during flower development, freezing stress, and salt stress

ABC (ATP-binding cassette) transporter proteins are one of the most extensive protein families known to date and are ubiquitously found in animals, plants, and microorganisms. ABCs have a variety of functions, such as plant tissue development regulation, hormone transport, and biotic and abiotic stress resistance. However, the gene characterization and function of the ABC gene family in almond (Prunus dulcis) have not been thoroughly studied. In this study, we identified 117 PdABC genes using the whole genome of ‘Wanfeng’ almond obtained by sequencing and explored their protein characterization. The PdABC family members were classified into eight subfamilies. The members of the same subfamily had conserved motifs but poorly conserved numbers of exons and introns and were unevenly distributed among the eight subfamilies and on the eight chromosomes. Expression patterns showed that PdABC family members were significantly differentially expressed during almond development, dormant freezing stress, and salt stress. We found that PdABC59 and PdABC77 had extremely high expression levels in pollen. PdABC63 and PdABC64 had high expression levels during almond petal development and multiple stages of flower development. PdABC98 was highly expressed in annual dormant branches after six temperature-freezing stress treatments. PdABC29, PdABC69, and PdABC98 were highly expressed under different concentrations of salt stress. This study preliminarily investigated the expression characteristics of ABC genes in different tissues of almond during flower development, freezing stress and salt stress, and the results will provide a reference for further in-depth research and breeding of almond in the future.

‘Glad to the heart to see any of my brothers’: exploring Irish family life through sibling relationships

ABSTRACT This article proposes using the sibling relationship as an historical lens into nineteenth-century Ireland. Often taken for granted in historiography, brothers and sisters influenced family financial decisions and provided emotional support to each other in childhood, adulthood, and into old age. They were members of each other’s social networks and could be a cause of worry, conflict, and tension within the home. As the longest-lasting relationship an individual experiences, siblings provide a unique vantage point for the historian to explore the role of family in society across the life cycle. Their presence, or lack thereof, is vital to a sibling’s identity. Whilst individuals shape their own identity in relation to their family and peers, people have their own ambitions, successes, and failures. Tracing these interactions allow the historian to similarly trace wider social and cultural change. This article uses two sets of siblings to explore how brothers and sisters consciously kept family connection, utilised it in times of crisis, and benefited from sibling support networks. Separated through migration, the migrant letters exchanged between the Sinclair family in County Tyrone and Philadelphia shed light on the emotional toll of migration and provide insight into everyday life in rural Ireland. Making use of genealogical methodologies and digitised collections, this article reveals how family stories can be pieced together using fragmentary sources across a diverse range of archives. A horizontal approach elucidates wider societal changes over generations of the family. This article uses the sibling relationship to unravel complex family networks and explore nineteenth-century Irish society through the family lens.

Predictable electronic tuning of FeII and RuII complexes via choice of azine: correlation of ligand pKa with Epa(MIII/II) of complex.

Five new mononuclear ruthenium(II) tris-ligated complexes have been synthesised, varying through the choice of azine in the family of 3-azinyl-4-(4-methylphenyl)-5-phenyl-4H-1,2,4-triazole ligands (Lazine): [Ru(Lpyridine)](PF6)2 (1), [Ru(Lpyridazine)](PF6)2 (2), [Ru(L4-pyrimidine)](PF6)2 (3), [Ru(Lpyrazine)](PF6)2 (4), [Ru(L2-pyrimidine)](PF6)2 (5). Three of them, 1·2MeCN·Et2O, 3·2MeCN·Et2O and 4·2MeCN, have been structurally characterised, confirming the presence of the meridional isomer, as was previously reported for the FeII analogues. Cyclic voltammetry studies, in dry CH3CN vs. Ag/0.01 M AgNO3, show that all five RuII complexes undergo a reversible RuIII/RuII process, with the midpoint potential (Em) increasing from 0.87 to 1.18 V as the azine is changed: pyridine < pyridazine < 2-pyrimidine < 4-pyrimidine < pyrazine. A strong inverse linear correlation (R2 = 0.98) is found between the RuIII/RuII redox potential and the calculated HOMO orbital energies, which is consistent with the expectation that it is easier to oxidise (lower Em) a metal ion with a higher HOMO orbital energy. The same trend was reported earlier for the family of analogous FeII complexes, albeit at lower values of Em in all cases. In addition, the ionisation potentials of the RuII complexes, as well as those of the other group 8 analogues (FeII and OsII), showed a linear relationship with Epa. As the MIII/II redox potentials of a family of complexes has been previously reported to correlate with ligand pKa values, a computational protocol to calculate, in silico, the pKa of the Lazine family of ligands was developed. A strong linear relationship was found between the readily calculated pKa of the Lazine ligand and the Epa of the MII complex, for all three families of complexes (R2 = 0.98).

Navigating the Role of Emotional Health and Positive Life Outlook on Work‐Life Balance in Professional Married Women

A diverse workforce is innovative and women are equally contributing to the country’s economic development along with men. In a dynamic business community, women are more enthusiastic and progressively using their potential for financial growth and providing benefits to their families as well. In the subcontinent, women also participate in the workforce and contribute to improving their quality of life and financial responsibilities. The objective of current research is to find out the relationship between emotional health, positive life orientation, and work‐life balance in professional married women. A correlational research design and purposive sampling strategy were utilized to conceptualize the study. A total of 300 professional married women who served in various positions in different organizations were selected. Standardized instruments were used to measure study variables along with sociodemographic Performa. Statistical findings of the study revealed a significant positive relationship between emotional wellness, positive life orientation, and work‐personal life enhancement ( ∗∗∗p &lt; 0.01, ∗∗p &lt; 0.1, ∗p &lt; 0.05) by using Pearson product‐moment correlation. Mediation through PLS revealed that positive life orientation mediates the relationship between emotional wellness and work‐life balance. Independent Sample T‐test results also revealed that working women living in the nuclear family system have higher work interference with personal life and personal life interference with work than those women who live in a joint family system. This research will be helpful for organizations to design a conducive and women‐friendly job environment and use women’s potential for constructive and productive professional growth and organizational progress.

Alkyl chain length influence of the functionalized diethanolamine ligand on the slow relaxation of the magnetization in {CoIII3DyIII3} complexes.

We report the synthesis, structural characterization and magnetic properties of a series of Co(III)/Dy(III) complexes built up from an N-alkyl derivatized amino-alcohol ligand diethanolamine, functionalized with CnH2n+1 alkyl chains (n = 3, 4, 6, 8 and 10). While n = 3 afforded a butterfly {CoIII2DyIII2} core, the other alkyl chains (n = 4, 6, 8) afforded hexanuclear triangle-in-triangle {CoIII3DyIII3} complexes as shown by single-crystal X-ray determinations. Infrared spectroscopy allows us to characterize the C10 derivative complex, which did not crystallize. Magnetic ac susceptibility data collected below 10 K at driving frequencies up to 10 kHz under zero-dc field and up to 1 T provide insight into the SMM behaviour of the studied complexes. The characteristic time of the magnetization dynamics can be understood in terms of the competing Raman, Direct and Orbach-like mechanisms. A relationship between the magnetization dynamics within the family of complexes and the increasing alkyl chain length is discussed.

Activation of alkyl hydroperoxides by manganese complexes of tmtacn for initiation of radical polymerisation of alkenes.

The activation of alkyl hydroperoxides to generate radicals is a key step in the initiation of radical polymerisations in many industrial applications, not least protective coatings. Cobalt soaps (Co(ii) alkyl carboxylates) are highly effective catalysts under ambient conditions but viable alternatives based on less scarce catalysts are desirable, with especially iron and manganese catalysts showing potential. Manganese complexes of the ligand N,N',N″-trimethyl-1,4,7-triazacyclononane (tmtacn) are long established as catalysts for organic oxidations with H2O2, however their reactivity with alkyl hydroperoxides is less studied especially in apolar solvents. Here we show that this family of complexes can be employed as catalysts for the decomposition of alkyl hydroperoxides in apolar solvents such as styrene/methyl methacrylate mixtures and resins based on styrene/bisphenol-A based diglycidyl ether bismethacrylate (BADGE-MA). The progress of alkene polymerisation in crosslinking resins is followed by Raman spectroscopy to establish its dependence on the oxidation state of the manganese catalyst used, as gelation time and onset of autoacceleration are of particular interest for many applications. We show, through reaction progress monitoring with UV/vis absorption and Raman spectroscopy, that the stability of the manganese complexes in the resin mixtures has a substantial effect on curing progress and that the oxidation state of the resting state of the catalyst is most likely Mn(ii), in contrast to reactions with H2O2 as oxidant in which the oxidation state of the resting state of catalyst is Mn(iii). Manganese complexes of tmtacn are shown to be capable initiators of alkene radical polymerisations, and their rich coordination and redox chemistry means that resin curing kinetics can potentially be tuned more readily than with cobalt alkyl carboxylates.

Factors Influencing Facemask and Hand Sanitizer use During the COVID-19 Pandemic in Odisha

This study endeavours to find out the various factors that determine the usage of facemasks and hand sanitizer among the rural people of Odisha (India) during the COVID-19 pandemic time. The study is based on a primary survey. In total, the study has collected 360 individual samples from three districts of Odisha. Additionally, the study applies a logistic regression model to empirically measure the impact of various socio-economic factors on the usage of facemasks and hand sanitizer. The major findings of the study depict that both behavioural and socio-economic factors are impacting the usage of facemasks and hand sanitizer among the people of rural Odisha. Some behavioural factors, such as “thinking of not being required," "no COVID patients in our areas”, and “feeling suffocation,” are highly restricting rural people from using facemasks. Similarly, some socio-economic factors like “being a male member, young age group, being unmarried, education level, joint family, having children under 5, pucca house, working in private or government organisations, and high income” are positively influencing the usage of facemasks and hand sanitizer among the rural people of Odisha.

Rationale behind Juvenile Delinquency in State of Uttar Pradesh in India: An Investigative Study

Juvenile’s rate of involving in crime has drastically increased during last few decades around the world. Inclination of children towards crime is due to many possible reasons such as family background, psychology, society, money, power and miscellaneous petty reasons. Indian criminal justice system is that which usually take action when any offence happened and will wait to happen even if they know about the post crime consequences. Today’s children are the future of tomorrow therefore efforts should be made to amend them from indulging in crime. The current study has been conducted in line to investigate the possible causes of juvenile delinquency and the most prevalent type of crimes among the juveniles of Uttar Pradesh region. Data was collected in year 2020-21 during COVID times from 61 juvenile subjects who either completed their punishments or through RTI. The study was assessed for involvement of juveniles in crime on the basis of gender ratio, age, education status, nuclear or joint family, alcoholism smoking habits, caste, religion, financial status, type of crime etc. The study outcomes reflected that large number of male is involved in crimes than females with maximum count from rural areas than urban places. Hindu’s are more in number than any other religion like Muslims, Sikhs or Christians. Teenagers from Rajput, Baniya, Jaat community juveniles are more indulged than a Scheduled Caste or other backward classes.

Social Factors Influencing Utilization of Old Age Homes by Elderly in Urban Area of South Chennai, Tamil Nadu.

Currently, most old age homes in India are completely occupied. Nowadays, nuclear families are more than joint families, and due to various factors such as urbanization, the elderly are deprived of essential care at home and are moved from their own homes to old-age homes. With the increasing geriatric population, this study explored the various social factors influencing the elderly to reside in old age homes. The study was conducted among 330 elderly in old age homes using simple random sampling. The study population included elderly above the age of 60 years and residing in old age homes, who were willing to participate. A pretested structured questionnaire with data on sociodemographic characteristics, family, financial support, and various other social factors was collected. Data were analyzed using SPSS. Among the respondents, 20.6% were supported by children financially and 18.5% had a pension. Almost 70% of the elderly were left unattended by friends and family. Care and support through means of calls, letters, and visits when analyzed showed that 27.3% were provided care and support through children and 33.6% were left unattended. Family members, friends, and relatives should be encouraged to give regular visits and spend time with the elderly so that the bonding will have a positive effect on their mental health. Aging and geriatric health should be considered sensitively and should be made mandatory for schools and colleges to arrange visits to old age homes, thereby keeping the younger generation aware of the issues.

Integrated Psychological Rehabilitation Program on Neurocognition, Social Skill, and Functional Disability in Persons with Schizophrenia: A Pilot Study

Abstract Introduction: Schizophrenia, a chronic and severe mental disorder, is characterized by disruptions in thinking, perception, emotions, and behavior. These disturbances are accompanied by significant cognitive and social skill deficits that affect their functional outcomes encompassing employment, independent living, social interactions, and community integration. To address these issues, the development of psychological rehabilitation programs addressing cognitive and social skill deficits becomes pivotal in schizophrenia care. Objective: The study was designed to develop modules for the integrated psychological rehabilitation program (IPRP) that focus on neurocognitive functions, social skills, and functional disability and evaluate its feasibility among schizophrenia patients. Materials and Methods: The present study made use of a pre- and posttest research design and used purposive sampling to recruit patients diagnosed with schizophrenia. Twelve participants completed the 1-month IPRP along with the pre- and posttest evaluations encompassing cognitive functions, social skills, and disability using the Bender Gestalt Test, Social Skills Assessment Screening Scale, NIMHANS neuropsychology battery, Postgraduate Institute Memory Scale, and WHO Disability Assessment Schedule II. IPRP consisted of psychoeducation, cognitive retraining, and social skills training. Results: The majority of the participants were college educated (91.7%), unemployed (83.3%), single (75%), males (75%), residing in urban areas (66.7%), and living in joint family (66.7%). Wilcoxon signed-rank test was used to compare pre- and posttest means. The results found significant improvements in various cognitive domains, including visuospatial ability (Z = 2.43, P = 0.015), remote (Z = 2.12, P = 0.034) and immediate memory (Z = 2.04, P = 0.042), verbal retention for similar (Z = 2.26, P = 0.024) and dissimilar pairs (Z = 2.82, P = 0.005), recognition (Z = 2.14, P = 0.032), total memory (Z = 3.06, P = 0.002), mental speed in terms of time taken (Z = 2.98, P = 0.003) and errors made (Z = 2.26, P = 0.024) on the digit symbol substitution test, comprehension (Z = 2.84, P = 0.004), social skills (Z = 2.807, P = 0.005), and overall disability (Z = 2.94, P = 0.003). Conclusion: The findings from the study underscore the potential of the IPRP in mitigating cognitive deficits, enhancing social skills, and reducing overall disability among schizophrenia patients.

A Cross-Sectional Study to Determine the Prevalence and Predictors of Depression and Anxiety in Type 2 Diabetes Patients in South India

Diabetic patients with depression or anxiety are more likely to develop diabetic complications and have a lower quality of life. The aim of the study is to determine the prevalence of depression and anxiety among type 2 diabetic patients and to identify the associated factors. A cross-sectional, observational study of type 2 diabetes mellitus outpatients, with diabetes-related conditions who attended the hospital from January to April 2023, was conducted by interviewing them using the Patient Health Questionnaire-9 for depression and Generalised Anxiety Disorders-7 for anxiety. Descriptive statistics, bivariate analysis, and multivariant regression were performed for statistical analysis. Out of 450 type 2 diabetic patients, 90% were between ages 30 and 45, 50.2% were male, 60% were living in rural areas, and 76.5% literate; most of them belong to the upper middle class (64%) and they live in joint family (32.7%). Depression and anxiety were observed among 65.3% and 62.4% of type 2 diabetic patients, respectively. When observing the severity, 47.8% of patients had mild depression, and 38.7% had minimal anxiety. Age group, socioeconomic status, treatment type, and years of diabetes were found to be factors associated with depression and family type is associated with anxiety. Hospitalized diabetics have higher depression and anxiety rates for multiple reasons. Therefore, diabetes management programmes should include regular depression and anxiety screenings to quickly identify and treat high-risk patients in healthcare facilities.

A Study on Practice of Reproductive Health Care Facilities and Family Planning Decisions of the Rural Adolescent in an area of Bogura District, Bangladesh

Adolescent’s reproductive health is a serious concern in Bangladesh. The present study is based on primary data collection and in-depth interviews of 150 rural adolescent females of Fulbari and Baiguni villages of Bogura district. The objectives of the study were to assess the level of knowledge attitude and practice on reproductive health issues, to assess the socio-demographic features of samples and to explore the level of knowledge &amp; awareness to demonstrate the role of the information &amp; education (media, counseling, services facilities) in the management of reproductive health issues among rural adolescent females. The mean age of the respondents were 16.2 years. School enrolment is still low (46%) and dropout rate is high (32%). A large number of rural adolescent females of the study area have been found to discontinue education after a few years of schooling. The data further shows that, in TV 7.31% attending health education and 12.19% to family planning program. More of the adolescents (60%) were aware of all least one family planning methods (Oral Pill). However, it is obvious that knowledge of various methods of contraception does not imply that the respondents actually knew how to use these methods effectively. The highest three methods they can named were oral pill 60%, Injection 35% and Implant/ Norplant 18.67%. Among all 72.64% were not known or received any information about the management of menstruation before their first menstruation. The study revealed that 72.41% of adolescent’s females, those were suffering from at least one complication or problems of menstruation and were not visited or seeking any consultation or treatment from any service providers available. Only 18% of them seek treatment or consultation from the service providers. Among these sick adolescents’ females who attended for consultation or treatments, 83.33% were not satisfied while only 16.67% express their satisfaction on the health care services. The social and religious constraints are strict in the culture and Islamic ideals of Bangladeshi people where the majority of whom still live in joint families. The study indicates that the rural adolescent females are poorly informed about most of the reproductive health issues. There also exist important misconceptions regarding healthy management of menstruation. Besides, there is big gap between their knowledge, attitude and practice. Parents, Guardians, teachers, religious leaders and community leaders (they are main gatekeeper) concern regarding management reproductive health issues of rural adolescent females.

Tuning valence tautomerism in a family of dinuclear cobalt complexes incorporating a conjugated bridging bis(dioxolene) ligand with weak communication.

Valence tautomerism (VT) involves the stimulated reversible intramolecular electron transfer between a redox-active metal and ligand. Dinuclear cobalt complexes bridged by bis(dioxolene) ligands can undergo thermally-induced VT with access to {CoIII-cat-cat-CoIII}, {CoIII-cat-SQ-CoII} and {CoII-SQ-SQ-CoII} states (cat2- = catecholate, SQ˙- = semiquinonate, CoIII refers to low spin CoIII, CoII refers to high spin CoII). The resulting potential for two-step VT interconversions offers increased functionality over mononuclear examples. In this study, the bis(dioxolene) ligand 3,3',4,4'-tetrahydroxy-5,5'-dimethoxy-benzaldazine (thMH4) was paired with Mentpa (tpa = tris(2-pyridylmethyl)amine, n = 0-3 corresponds to methylation at 6-position of the pyridine rings) to afford [{Co(Mentpa)}2(thM)](PF6)2 (1a, n = 0; 2a, n = 2; 3a, n = 3). Structural, magnetic susceptibility and spectroscopic data show that 1a and 3a remain in the temperature invariant {CoIII-cat-cat-CoIII} and {CoII-SQ-SQ-CoII} forms in the solid state, respectively. In contrast, 2a exhibits incomplete thermally-induced VT between these two tautomeric forms via the mixed {CoIII-cat-SQ-CoII} tautomer. In solution, room temperature electronic absorption spectra are consistent with the assignments from the solid-state, with VT observed only for 2a. From electrochemistry, the proximity of the two 1e--processes for the thMn- ligand indicates weak electronic communication between the two dioxolene units, supporting the potential for a two-step VT interconversion in thMn- containing complexes. Comparison of the redox potentials of the Co and thMn- processes suggests that only 2a has these processes in sufficient proximity to afford the thermally-induced VT observed experimentally. Density functional theory calculations are consistent with the prerequisite energy ordering for a two-step transition for 2a, and temperature invariant {CoIII-cat-cat-CoIII} and {CoII-SQ-SQ-CoII} states for 1a and 3a, respectively. This work presents the third example, and the first formally conjugated example, of a bridging bis(dioxolene) ligand that can afford two-step VT in a Co complex, suggesting new possibilities towards applications based on multistep switching.

Catalytic reduction of oxygen to water by non-heme iron complexes: exploring the effect of the secondary coordination sphere proton exchanging site.

In this study, we prepared non-heme FeIII complexes (1, 2, and 3) of an N4 donor set of ligands (H2L, Me2L, and BPh2L). 1 is supported by a monoanionic bispyridine-dioxime ligand (HL). In 2 and 3, the primary coordination sphere of Fe remained similar to that in 1, except that the oxime protons of the ligand were replaced with two methyl groups and a bridging -BPh2 moiety, respectively. X-ray structures of the FeII complexes (1a and 3a) revealed similar Fe-N distances; however, they were slightly elongated in 2a. The FeIII/FeII potential of 1, 2, and 3 appeared at -0.31 V, -0.25 V, and 0.07 V vs. Fc+/Fc, respectively, implying that HL and Me2L have comparable donor properties. However, BPh2L is more electron deficient than HL or Me2L. 1 showed electrocatalytic oxygen reduction reaction (ORR) activity in acetonitrile in the presence of trifluoroacetic acid (TFAH) as the proton source at Ecat/2 = -0.45 V and revealed selective 4e-/4H+ reduction of O2 to H2O. 1 showed an effective overpotential (ηeff) of 0.98 V and turnover frequency (TOFmax) of 1.02 × 103 s-1. Kinetic studies revealed a kcat of 2.7 × 107 M-2 s-1. Strikingly, 2 and 3 remained inactive for electrocatalytic ORR, which established the essential role of the oxime scaffolds in the electrocatalytic ORR of 1. Furthermore, a chemical ORR of 1 has been investigated using decamethylferrocene as the electron source. For 1, a similar rate equation was noted to that of the electrocatalytic pathway. A kcat of 6.07 × 104 M-2 s-1 was found chemically. Complex 2, however, underwent a very slow chemical ORR. Complex 3 chemically enhances the 4e-/4H+ reduction of O2 and exhibits a TOF of 0.24 s-1 and a kcat value of 2.47 × 102 M-1 s-1. Based on the experimental observations, we demonstrate that the oxime backbone of the ligand in 1 works as a proton exchanging site in the 4e-/4H+ reduction of O2. The study describes how the ORR is affected by the tuning of the ligand scaffold in a family of non-heme Fe complexes.