Enhancing the performance of organic phototransistors using a sandwich-heterostructure.

To weaken the adverse effects of traditional planar heterojunctions on phototransistors, an effective strategy for achieving low dark-current and high photoresponsive organic phototransistors via constructing a sandwich heterostructure is demonstrated. This work offers a new route for the design and development of high-performance phototransistor devices.

Bulk Trapping Organic Semiconductor with Amino-Additive Enabling Ultrasensitive NO2 Sensors.

Organic semiconductor (OSC) gas sensors have garnered considerable attention due to their promising selectivity and inherent flexibility. Introducing a functional group or modification layer is an important route to modulate the doping/trapping state of the active layer and the gas absorption/desorption process. However, the majority of the functionalization lies in the surface/interface assembling process, which is difficult to control the functional group density. This in turn brings challenges for precise modulation of the charge transport and the doping/trapping density, which will affect the repeatability and reproducibility of sensing performance. Herein, we propose a facile bulk trapping strategy incorporating amino-terminated additive molecules via the vacuum deposition process, achieving ultrahigh sensitivity of ∼2000%/ppm at room temperature to NO2 gas and approaching ∼3000%/ppm at 50 °C. Additionally, the device exhibits commendable reproducibility, stability, and low concentration detection ability, reaching down to several ppb, indicating promising potential for future applications. Comprehensive analysis of electrical properties and density functional theory calculations reveals that these exceptional properties arise from the favorable electrical characteristics of the bulk trapping structure, the high mobility of C8-BTBT, and the elevated adsorption energy of NO2. This approach enables the construction of stable and reproducible sensitive sensors and helps to understand the sensing mechanism in OSC gas sensors.

Multi-trajectories of health-related quality of life and their associated factors in patients with nasopharyngeal carcinoma: A longitudinal study.

BACKGROUND: The trajectories of health-related quality of life (HRQoL) of nasopharyngeal carcinoma (NPC) during and after the treatment along with their associated factors are seldom investigated in longitudinal studies. This study aims to investigate the longitudinal trajectories of HRQoL over time and their associated factors in patients with newly diagnosed NPC. METHODS: Between July 2018 and September 2019, a total of 500 patients were finally involved in this study. HRQoL was measured at four time points, from before treatment to the follow-up period after treatment. Group-based multi-trajectory modeling was applied to identify trajectories of five HRQoL functioning domains during the longitudinal period. Multinomial logistic regression models were applied to investigate potential independent factors associated with the multi-trajectory groups. RESULTS: We identified four distinct multi-trajectory groups, including the "initially lowest functioning" group (19.8%), the "initially lower functioning" group (20.8%), the "initially higher functioning" group (46.0%), and the "consistently highest functioning" group (13.4%). Patients who were older than 45 years or had T4 stage disease were more likely to be in the "initially lowest functioning" group, while those with EBV DNA ≥ 1500 copies/mL before the treatment were more likely to be in the "initially lowest functioning" or the "initially lower functioning" groups. CONCLUSIONS: We report the presence of heterogeneity in HRQoL trajectories among patients with NPC, and found that older age, advanced T stage, and higher EBV DNA level before treatment were significantly associated with poor HRQoL trajectories. Further studies are needed to examine the generalizability of these identified HRQoL trajectories and their associations with psychosocial and survival outcomes.

Family context as a double-edged sword for psychological distress amid the COVID-19 pandemic with the mediating effect of individual fear and the moderating effect of household income.

Background: The COVID-19 pandemic drives psychological distress. Previous studies have mostly focused on individual determinants but overlooked family factors. The present study aimed to examine the associations of individual and family factors with psychological distress, and the mediating effect of individual fear and the moderating role of household income on the above associations. Methods: We conducted a population-based cross-sectional survey on Chinese adults in Hong Kong from February to March 2021 (N = 2,251) to measure the independent variables of anti-epidemic fatigue, anti-epidemic confidence, individual and family members' fear of COVID-19, and family well-being (range 0-10), and the dependent variable of psychological distress (through four-item Patient Health Questionnaire, range 0-4). Results: Hierarchical regression showed that anti-epidemic fatigue was positively (ß = 0.23, 95% CI [0.18, 0.28]) while anti-epidemic confidence was negatively (ß = -0.29, 95% CI [-0.36, -0.22]) associated with psychological distress. Family members' fear of COVID-19 was positively (ß = 0.11, 95% CI [0.05, 0.16]) while family well-being was negatively (ß = -0.57, 95% CI [-0.63, -0.51]) associated with psychological distress. Structural equation model showed that individual fear mediated the above associations except for family well-being. Multi-group analyses showed a non-significant direct effect of anti-epidemic confidence and a slightly stronger direct effect of family well-being on psychological distress among participants with lower incomes, compared to those with higher incomes. Conclusion: We have first reported the double-edged effect of family context on psychological distress, with the positive association between family members' fear of COVID-19 and psychological distress fully mediated by individual fear and the negative association between family well-being and psychological distress moderated by income level. Future studies are warranted to investigate how the contagion of fear develops in the family and how the inequality of family resources impacts family members' mental health amid the pandemic.

Factors associated with willingness and preferences to attend family services in Hong Kong: A population-based survey.

Objective: Family services are open to the community at large as well as vulnerable groups; however, little is known about the willingness of communities to attend such services. We investigated the willingness and preferences to attend family services and their associated factors (including sociodemographic characteristics, family wellbeing, and family communication quality) in Hong Kong. Methods: A population-based survey was conducted on residents aged over 18 years from February to March 2021. Data included sociodemographic characteristics (sex, age, education, housing type, monthly household income, and the number of cohabitants), willingness to attend family services to promote family relationships (yes/no), family service preferences (healthy living, emotion management, family communication promotion, stress management, parent-child activities, family relationship fostering, family life education, and social network building; each yes/no), family wellbeing, and family communication quality (both scores 0-10). Family wellbeing was assessed using the average scores of perceived family harmony, happiness and health (each score 0-10). Higher scores indicate better family wellbeing or family communication quality. Prevalence estimates were weighted by sex, age and educational level of the general population. Adjusted prevalence ratios (aPR) for the willingness and preferences to attend family services were calculated in relation to sociodemographic characteristics, family wellbeing, and family communication quality. Results: Overall, 22.1% (1,355/6,134) and 51.6% (996/1,930) of respondents were willing to attend family services to promote relationships or when facing problems, respectively. Older age (aPR = 1.37-2.30, P < 0.001-0.034) and having four or more cohabitants (aPR = 1.44-1.53, P = 0.002-0.003) were associated with increased aPR of willingness for both situations. Lower family wellbeing and communication quality were associated with lower aPR for such willingness (aPR = 0.43-0.86, P = 0.018-<0.001). Lower family wellbeing and communication quality were associated with preferences for emotion and stress management, family communication promotion, and social network building (aPR = 1.23-1.63, P = 0.017-<0.001). Conclusions: Lower levels of family wellbeing and communication quality were associated with unwillingness to attend family services and preferences for emotion and stress management, family communication promotion, and social network building.

Mycoviral gene integration converts a plant pathogenic fungus into a biocontrol agent.

Mycovirus-infected fungi can suffer from poor growth, attenuated pigmentation, and virulence. However, the molecular mechanisms of how mycoviruses confer these symptoms remain poorly understood. Here, we report a mycovirus Stemphylium lycopersici alternavirus 1 (SlAV1) isolated from a necrotrophic plant pathogen Stemphylium lycopersici that causes altered colony pigmentation and hypovirulence by specifically interfering host biosynthesis of Altersolanol A, a polyketide phytotoxin. SlAV1 significantly down-regulates a fungal polyketide synthase (PKS1), the core enzyme of Altersolanol A biosynthesis. PKS1 deletion mutants do not accumulate Altersolanol A and lose pathogenicity to tomato and lettuce. Transgenic expression of SlAV1 open-reading frame 3 (ORF3) in S. lycopersici inhibits fungal PKS1 expression and Altersolanol A accumulation, leading to symptoms like SlAV1-infected fungal strains. Multiple plant species sprayed with mycelial suspension of S. lycopersici or S. vesicarium strains integrating and expressing ORF3 display enhanced resistance against virulent strains, converting the pathogenic fungi into biocontrol agents. Hence, our study not only proves inhibiting a key enzyme of host phytotoxin biosynthesis as a molecular mechanism underlying SlAV1-mediated hypovirulence of Stemphylium spp., but also demonstrates the potential of mycovirus-gene integrated fungi as a potential biocontrol agent to protect plants from fungal diseases.

COVID-19 pandemic fatigue and its sociodemographic and psycho-behavioral correlates: a population-based cross-sectional study in Hong Kong.

Pandemic fatigue is a growing public health concern of the lingering COVID-19 pandemic. Despite its widespread mass media coverage, systematic empirical investigations are scarce. Under the Hong Kong Jockey Club SMART Family-Link Project, we conducted online and telephone surveys amid the pandemic in February to March 2021 to assess self-reported pandemic fatigue (range 0-10) in Hong Kong adults (N = 4726) and its associations with sociodemographic and psycho-behavioral (high vs low to moderate) variables. Data were weighted by sex, age, and education of the general population. Binary logistic regression models yielded adjusted odds ratios (aORs) for high pandemic fatigue (score ≥ 7) for sociodemographic and psycho-behavioral variables. 43.7% reported high pandemic fatigue. It was less common in older people (55-64 years: aOR 0.56, 95% CI 0.39-0.82; 65 + years: 0.33, 0.21-0.52) versus age group 18-24 years, but more common in those with tertiary education (1.36, 1.15-1.62) versus secondary or below. High pandemic fatigue was positively associated with depressive symptoms (aOR 1.83, 95% CI 1.55-2.17), anxiety symptoms (1.87, 1.58-2.20), loneliness (1.75, 1.32-2.31), personal fear of COVID-19 (2.61, 2.12-3.23), family fear of COVID-19 (2.03, 1.67-2.47), and current alcohol use (1.16, 1.00-1.33), but negatively associated with self-rated health (0.79, 0.68-0.92), personal happiness (0.63, 0.55-0.72), personal adversity coping capability (0.71, 0.63-0.81), family adversity coping capability (0.79, 0.69-0.90), family well-being (0.84, 0.73-0.97), family communication quality (0.86, 0.75-0.98), and frequent home exercise (0.82, 0.69-0.96; versus less frequent). We first used a single-item tool to measure COVID-19 pandemic fatigue, showing that it was common and associated with worse mental health, lower levels of personal and family well-being and alcohol use.

Patterns of Perceived Harms and Benefits of the COVID-19 Outbreak in Hong Kong Adults: A Latent Profile Analysis.

The COVID-19 pandemic caused different types of harms and benefits, but the combined patterns of perceived harms and benefits are unclear. We aimed to identify the patterns of perceived harms and benefits of the COVID-19 outbreak and to examine their associations with socio-demographic characteristics, happiness, and changes in smoking and drinking. A population-based cross-sectional online survey was conducted in May 2020 on Hong Kong adults (N = 4520). Patterns of perceived harms and benefits of COVID-19 were identified using latent profile analysis. Their associations with socio-demographic characteristics, happiness, and changes in smoking and drinking were examined using multinomial logistic regression. We identified three distinct patterns: indifferent (66.37%), harm (13.28%), and benefit (20.35%). Compared with the indifferent subgroup, the harm subgroup was younger, less happy, and had increased drinking, and hence might be at higher risk, whereas the benefit subgroup was more likely to be female, live with one or more cohabitants, have postsecondary education, be happier, and have decreased drinking, and could be more adaptive. Future studies can target the harm subgroup to facilitate their positive adjustments.

A Population Study on COVID-19 Information Sharing: Sociodemographic Differences and Associations with Family Communication Quality and Well-Being in Hong Kong.

Family support through the sharing of information helps to shape and regulate the health and behaviours of family members, but little is known about how families are sharing COVID-19-related information, or about its associations with family communication quality and well-being. We examined the associations of COVID-19 information sharing methods with sociodemographic characteristics, the perceived benefits of information communication and technology (ICT) methods, and family communication quality and well-being in Hong Kong. Of 4852 respondents (53.2% female, 41.1% aged over 55 years), the most common sharing method was instant messaging (82.3%), followed by face-to-face communication (65.7%), phone (25.5%) and social media (15.8%). Female sex (adjusted prevalence ratio (aPR) 1.09), older age (aPRs 1.14-1.22) and higher household income (aPR 1.06) (all p ≤ 0.04) were associated with instant messaging use, while post-secondary education was associated with face-to-face (aPR 1.10), video call (aPR 1.79), and email (aPR 2.76) communications (all p ≤ 0.03). Each ICT sharing method used was associated with a higher likelihood of both reported benefits (aPRs 1.26 and 1.52), better family communication quality and family well-being (adjusted ßs 0.43 and 0.30) (all p ≤ 0.001). We have first shown that COVID-19 information sharing in families using both traditional methods and ICTs, and using more types of methods, was associated with perceived benefits and better family communication quality and well-being amidst the pandemic. Sociodemographic differences in COVID-19 information sharing using ICTs were observed. Digital training may help enhance social connections and promote family well-being.

Skipping Breakfast and Eating Breakfast Away From Home Were Prospectively Associated With Emotional and Behavioral Problems in 115,217 Chinese Adolescents.

BACKGROUND: Breakfast is deemed the most important meal of the day. We examined the prospective associations of breakfast habits with emotional/behavioral problems in adolescents and potential effect modification. METHODS: 115,217 Primary 6 students (United States Grade 6; mean age, 11.9; standard deviation [SD], 0.59 years) who attended the Student Health Service of Department of Health in Hong Kong in 2004/05, 2006/07, 2008/09 were followed till Secondary 6 (United States Grade 12). Emotional/behavioral problems were biennially examined using Youth Self-Report since Secondary 2 (United States Grade 8). Lifestyles were biennially examined using standardized questionnaires since Primary 6. Prospective associations of breakfast habit with emotional/behavioral problems and potential effect modification were examined using generalized estimating equations. RESULTS: Compared with eating breakfast at home, eating breakfast away from home was significantly associated with total emotional/behavioral problems and seven syndromes, including withdrawal, somatic complaints, anxiety/depression, thought problems, attention problems, delinquent behaviors, and aggressive behaviors (adjusted odds ratios [AORs] 1.22-2.04), while skipping breakfast showed stronger associations with the above problems and social problems (AORs 1.34-2.29). Stronger associations were observed in younger students for total and attention problems (P < 0.03) and in those with lower weight status for delinquent behaviors (P = 0.005). CONCLUSION: Eating breakfast away from home and especially skipping breakfast were prospectively associated with adolescent emotional/behavioral problems. The associations weakened with increasing age for total emotional/behavioral and attention problems, and weakened with higher weight status for delinquent behaviors, highlighting the vulnerability of younger and underweight children. If the associations are causal, increasing home breakfast may reduce adolescent emotional/behavioral problems and benefit psychosocial health.

Family E-Chat Group Use Was Associated with Family Wellbeing and Personal Happiness in Hong Kong Adults amidst the COVID-19 Pandemic.

Instant messaging (IM) is increasingly used for family communication amidst the COVID-19 pandemic. However, evidence remains scarce on how family e-chat groups were used and their associations with family and individual wellbeing amidst the pandemic. The numbers of family e-chat groups, functions used, and messages sent and received daily in groups were reported by 4890 adults in May 2020, and their associations with family wellbeing and personal happiness and the mediation effect of family communication quality were examined. Results showed that sending/receiving text messages was most commonly used, followed by receiving/sending photos/pictures, making voice calls, receiving/sending short videos and voice messages, and making video calls. Women and older people used more non-text functions. Higher levels of family wellbeing and personal happiness were associated with having more groups, receiving/sending photos/pictures, video calls, more IM functions used, and more IM messages received/sent daily. Forty-six point two to seventy-five point five percent of their associations with more groups and more functions used were mediated by family communication quality. People having more family e-chat groups and using more IM functions may be more resilient amidst the pandemic, while those without or with low use of family e-chat groups amidst the pandemic would need more attention and assistance in the presence of social distancing.

Molecular characterization of a novel fusarivirus infecting the plant-pathogenic fungus Alternaria solani.

A novel mycovirus belonging to the proposed family "Fusariviridae" was discovered in Alternaria solani by sequencing a cDNA corresponding to double-stranded RNA extracted from this phytopathogenic fungus. The virus was tentatively named "Alternaria solani fusarivirus 1" (AsFV1). AsFV1 has a single-stranded positive-sense (+ssRNA) genome of 6845 nucleotides containing three open reading frames (ORFs) and a poly(A) tail. The largest ORF, ORF1, encodes a large polypeptide of 1,556 amino acids (aa) with conserved RNA-dependent RNA polymerase and helicase domains. The ORF2 and ORF3 have overlapping regions, encoding a putative protein of 522 amino acids (aa) and a putative protein of 105 amino acids (aa), respectively, both of unknown function. A multiple sequence alignment and phylogenetic analysis revealed that AsFV1 could be a new member of the "Fusariviridae". This is the first report of the full-length nucleotide sequence of a fusarivirus that infects Alternaria solani.

Increasing socioeconomic disparities in sedentary behaviors in Chinese children.

BACKGROUND: Sedentary behaviors are prevalent in Chinese children, however, the studies on their trends and socioeconomic disparities are scarce. We examined the time trends of daily television (TV) viewing and video game playing and the associated socioeconomic factors in Chinese children in Hong Kong, the most developed and westernized city in China. METHODS: In a panel data study involving 538,300 primary four and 510,294 primary six students from 1999/2000 to 2008/09, data on socioeconomic status, sedentary behaviors (TV viewing and video game playing) and other lifestyle habits were collected using a self-administered questionnaire. Trends in sedentary behaviors over time were assessed. Their socioeconomic disparities were examined by interactions in generalized estimating equations with the adjustment for weight status and extracurricular physical activities. RESULTS: The age and sex-standardized prevalence of ≥2 h daily TV viewing decreased from 51.4% (95% confidence interval [CI] 51.1-51.8%) in 1999/2000 to 43.8% (95% CI 43.4-44.2%) in 2008/09 (P for trend < 0.001), whereas that of ≥1 h daily video game playing increased from 8.2% (95% CI 7.9-8.4%) to 22.4% (95% CI 22.0-22.7%). Both sedentary behaviors were more prevalent in boys than girls, but the disparities decreased over time (Ratio of odds ratio [ROR] = 0.996 and 0.924 for TV viewing and video game playing, respectively). In contrast, both sedentary behaviors were increasingly more prevalent in children whose parents had lower education levels or non-managerial/professional occupations (ROR 1.006-1.082). CONCLUSIONS: Children in lower socioeconomic families in Hong Kong were increasingly at risk of having sedentary behaviors over years and thus deserve more attention. Effective strategies targeting children and/or their parents of lower socioeconomic status are needed to reduce sedentary behaviors.

Luminescent cadmium(ii) coordination polymers of 1,2,4,5-tetrakis(4-pyridylvinyl)benzene used as efficient multi-responsive sensors for toxic metal ions in water.

Reactions of Cd(NO3)2·4H2O with 1,2,4,5-tetrakis(4-pyridylvinyl)benzene (4-tkpvb) and 5-tert-butylisophthalic acid (5-tert-H2BIPA), 1,3,5-benzenetricarboxylic acid (1,3,5-H3BTC) or 1,4-naphthalenedicarboxylic acid (1,4-H2NDC) under solvothermal conditions afforded three two-dimensional (2D) Cd(ii) coordination polymers [Cd(4-tkpvb)(5-tert-BIPA)]n (1), [{Cd(4-tkpvb)(1,3,5-HBTC)}·0.5DMF]n (2) and [Cd(4-tkpvb)(1,4-NDC)]n (3). Compounds 1-3 were structurally characterized by IR, elemental analysis, powder X-ray diffraction, and single crystal X-ray diffraction. Compounds 1-3 possess unique 2D networks in which 1D double chains [Cd2L2]n (L = 5-tert-BIPA or 1,3,5-HBTC) (1-2) or 1D linear chains [Cd(1,4-NDC)]n (3) are linked by 4-tkpvb ligands. Upon UV light excitation, a 4-tkpvb solution in DMF showed an emission band centered at 446 nm with a shoulder at 475 nm. The addition of Hg2+ ions into the 4-tkpvb solution in DMF remarkably changed its colour from colourless to yellow under natural light, or from blue to grey yellow under UV light, which were clearly visible to the naked eye. Compounds 1-3 suspended in water could emit yellow-green light under UV light irradiation. The representative compound 1 was confirmed to be an uncommon multi-responsive luminescent sensor for Hg2+, CrO42- and Cr2O72- ions in water by the luminescence quenching method. The detection limits for these species were 0.15 µM (Hg2+), 0.08 µM (CrO42-) and 0.12 µM (Cr2O72-), respectively. The luminescence quenching mechanism studies revealed that these quenching processes were involved in either the interaction of Hg2+ with free pyridyl groups in 1 or the overlap between the absorption band of CrO42- or Cr2O72- and the excitation and/or emission bands of 1.

BZLF1 Attenuates Transmission of Inflammatory Paracrine Senescence in Epstein-Barr Virus-Infected Cells by Downregulating Tumor Necrosis Factor Alpha.

UNLABELLED: Recent studies have shown that inflammatory responses trigger and transmit senescence to neighboring cells and activate the senescence-associated secretory phenotype (SASP). Latent Epstein-Barr virus (EBV) infection induces increased secretion of several inflammatory factors, whereas lytic infections evade the antiviral inflammatory response. However, the changes in and roles of the inflammatory microenvironment during the switch between EBV life cycles remain unknown. In the present study, we demonstrate that latent EBV infection in EBV-positive cells triggers the SASP in neighboring epithelial cells. In contrast, lytic EBV infection abolishes this phenotype. BZLF1 attenuates the transmission of paracrine senescence during lytic EBV infection by downregulating tumor necrosis factor alpha (TNF-α) secretion. A mutant BZLF1 protein, BZLF1Δ207-210, that cannot inhibit TNF-α secretion while maintaining viral transcription, fails to block paracrine senescence, whereas a neutralizing antibody against TNF-α is sufficient to restore its inhibition. Furthermore, latent EBV infection induces oxidative stress in neighboring cells, while BZLF1-mediated downregulation of TNF-α reduces reactive oxygen species (ROS) levels in neighboring cells, and ROS scavengers alleviate paracrine senescence. These results suggest that lytic EBV infection attenuates the transmission of inflammatory paracrine senescence through BZLF1 downregulation of TNF-α secretion and alters the inflammatory microenvironment to allow virus propagation and persistence. IMPORTANCE: The senescence-associated secretory phenotype (SASP), an important tumorigenic process, is triggered and transmitted by inflammatory factors. The different life cycles of Epstein-Barr virus (EBV) infection in EBV-positive cells employ distinct strategies to modulate the inflammatory response and senescence. The elevation of inflammatory factors during latent EBV infection promotes the SASP in uninfected cells. In contrast, during the viral lytic cycle, BZLF1 suppresses the production of TNF-α, resulting in the attenuation of paracrine inflammatory senescence. This finding indicates that EBV evades inflammatory senescence during lytic infection and switches from facilitating tumor-promoting SASP to generating a virus-propagating microenvironment, thereby facilitating viral spread in EBV-associated diseases.

Synthesis of DMF-protected Au NPs with different size distributions and their catalytic performance in the Ullmann homocoupling of aryl iodides.

DMF-stabilized Au nanoparticles (NPs) with three different particle sizes were prepared by controlling the reaction temperatures and times. In the absence of any additional ligands, these Au NPs showed high catalytic activity in the Ullmann homocoupling of aryl iodides in DMF. The effects of Au particle size on the coupling reaction were investigated by the use of three Au catalysts with mean particle sizes of ca. 1.0 nm, 2.5 nm, and 5.5 nm, respectively. The catalytic activity of the Au NPs was found to be in the order of Au (2.5 nm) > Au (<1.0 nm) > Au (5.5 nm), indicating that surface Au atoms do not have the same catalytic activity toward such a homocoupling reaction.

Synthesis and structure of a ferric complex of 2,6-di(1H-pyrazol-3-yl)pyridine and its excellent performance in the redox-controlled living ring-opening polymerization of ε-caprolactone.

The reaction of FeCl3 with a pincer ligand, 2,6-di(1H-pyrazol-3-yl)pyridine (bppyH2), produced a mononuclear Fe(III) complex [Fe(bppyH2)Cl3] (1), which could be reduced to the corresponding Fe(II) dichloride complex [Fe(bppyH2)Cl2] (2) by suitable reducing agents such as Cp2Co or Fe powder. 1 and 2 exhibited a reversible transformation from each other with appropriate redox reagents. 1 could be utilized as a pre-catalyst to initiate the ring-opening polymerization of ε-caprolactone in the presence of alcohol but did not work. The 1/alcohol system displayed characteristics of a well-controlled polymerization with the resulting poly(ε-caprolactone) having low molecular weight distributions, a linear tendency of molecular weight evolution with conversion, and polymer growth observed for the sequential additions of ε-caprolactone monomer to the polymerization reaction. The polymerization was completely turned off by the in situ reduction of the catalytic Fe center via Cp2Co and then turned back upon the addition of [Cp2Fe]PF6. The rate of polymerization was modified by switching in situ between the Fe(III) and Fe(II) species.

Assembly of new Mo/Cu/S clusters from [Et4N][Tp*MoS(S4)] and Cu(I) salts: syntheses, structures and third-order nonlinear optical properties.

Reactions of [Et4N][Tp*MoS(S)4] (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) (1) with 3 equiv. of CuX (X = Cl, Br, I, CN) or [Cu(MeCN)4]ClO4 in CH2Cl2-MeCN or CH2Cl2-DMF afforded [Et4N]2[Tp*Mo(µ3-S)3(CuCl)3(µ3-Cl)] (2), [Et4N][Tp*Mo(µ3-S)3(CuX)3] (3: X = Br; 4: X = I), [Et4N][Tp*MoO(µ-S)2(CuX)] (5: X = I; 6: X = CN) and [Tp*Mo(µ3-S)3Cu3(µ3-S')]4 (7). Compounds 2-7 were characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H NMR, electrospray ion mass spectra (ESI-MS) and X-ray crystallography. The cluster dianion of 2 has a complete cubane-like [Tp*Mo(µ3-S)3(CuCl)3(µ3-Cl)] structure while the anion of 3 or 4 consists of an incomplete cubane-like [Tp*Mo(µ3-S)3(CuX)3] structure. The anion of 5 or 6 has a binuclear structure, in which one [Tp*MoO(µ-S)2] moiety and one CuX unit are linked by a pair of µ-S atoms. The structure of 7 may be considered as a supercube whose eight corners are occupied by four incomplete cubane-like [Tp*Mo(µ3-S)3Cu3] fragments and four µ3-S' atoms. The third-order nonlinear optical (NLO) properties of 2-6 in DMF were investigated by femtosecond degenerate four-wave mixing (DFWM) technique with a 80 fs pulse width at 800 nm. Compounds 2-6 exhibited good NLO performances and their NLO responses were enhanced relative to that of 1.

An unprecedented octahedral {Cd30} nanocage supported by twelve pendant-armed tetraacetate macrocyclic ligands.

An unprecedented octahedral {Cd(30)} nanocage supported by twelve pendant-armed tetraacetate macrocyclic ligands was synthesized through the reaction of macrocyclic tetraethyl ester and Cd(OAc)(2)·2H(2)O in a 1 : 2 stoichiometry, where the surface photovoltage and photoluminescent properties have been studied for the nanocage.

Formation of N-heterocyclic diphosphine ligands from Ag(I)-assisted condensation reactions between bdppeda and formaldehyde and their binuclear silver(I) complexes.

The reaction of [Ag(MeCN)(4)]ClO(4) with N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylenediamine (dppeda) in CH(2)Cl(2)/MeOH afforded an unexpected cationic binuclear complex [Ag(2)(L(1))(2)(η,η-µ-ClO(4))(2)](ClO(4))(2) (L(1) = N,N'-bis(diphenylphosphanylmethyl)-3H-4,5-dihydroimidazole-1-ium) (1). Compound 1 was also prepared in high yield from reactions of [Ag(MeCN)(4)]ClO(4) with N,N'-bis(diphenylphosphanylmethyl)ethylenediamine (bdppeda) in the presence of formaldehyde (HCHO) or formic acid (HCOOH). Analogous reactions of AgCl with bdppeda and HCHO resulted in the formation a neutral binuclear complex [Ag(2)(L(2))(2)(µ-Cl)(2)] (L(2) = N,N-bis(diphenylphosphanylmethyl)-tetrahydroimidazole) (2). Treatment of 1 with concentrated HCl gave rise to a partially anion-exchanged product [Ag(2)(L(1))(2)(µ-Cl)(2)](ClO(4))(2) (3). Compounds 1 and 3 have a similar cationic binuclear structure, in which a [Ag(2)(η,η-µ-ClO(4))(2)] or [Ag(2)(µ-Cl)(2)] ring is sandwiched by two in situ-formed cationic L(1) ligands. The L(1) ligand may be generated by the Ag(I)-assisted condensation reaction between bdppeda and HCHO or HCOOH. Compound 2 holds a neutral binuclear structure, in which a [Ag(2)(µ-Cl)(2)] ring is connected by two in situ-formed L(2) ligands from its top and bottom sites. The neutral ligand L(2) may be produced from another Ag(I)-assisted condensation reaction between bdppeda and HCHO. The in situ formation of the L(1) and L(2) ligands provides a new route to the N-heterocyclic diphosphine ligands, and an interesting insight into the coordination chemistry of their metal complexes.