Risk Factors for Overweight and Obesity in Children Attending the First Year of Primary Schools in Modena, Italy.

Over the last four decades, childhood overweight/obesity has dramatically increased, becoming a significant public health concern. The main aims of this study were to investigate the prevalence of overweight/obesity among first-year primary schools children in Modena and to identify the associated risk factors. Data were collected on the socio-demographic characteristics of family and weight, height, dietary habits and sedentary behaviours of the children, and on the parents' perception of their child's weight status, through an anonymous questionnaire administered to parents. The questionnaires were delivered by 660 out of 890 (74.2%) families, and after excluding those without anthropometric data, 588 children were included in the study. The prevalence of overweight/obesity among the children was 25.2%, significantly lower in children born to parents with a high education, and higher among children born to foreign parents and overweight/obese mothers. The multivariable analysis showed that the children most likely to become overweight/obese were those who skipped breakfast (OR 2.3, 95%CI 1.3-4.2) and/or mid-morning snacks (OR 3.2, 95%CI 1.5-6.5). Breakfast consumption was positively associated with higher parental education levels, whereas skipping mid-morning snacks is more frequent among children born to foreign parents and overweight/obese mothers. Moreover, 84.7% of the parents of overweight/obese children underestimated their child's weight status. One in four 6-7 year-old children is already overweight or obese. Childhood overweight/obesity is significantly associated with unhealthy lifestyles and family lifestyle. It is therefore essential to implement public health intervention programs aimed at both parents and children, in order to promote healthy lifestyles in early childhood.

A systematic review on biomonitoring of individuals living near or working at solid waste incinerator plants.

Background: Solid waste incinerators (SWI) emit several pollutants among which polychlorodibenzodioxins and furans (PCDD/Fs), polychlorobiphenyls, metals, monocyclic and polycyclic aromatic hydrocarbons (PAHs).Aim of the study: To present a systematic review of peer-reviewed literature on human biological monitoring of exposure and effect following potential exposure to SWI pollutants to bring together evidences and to highlight strengths and deficiencies of the studies conducted so far.Methods: Relevant studies on biomonitoring of individuals living near or working at SWIs were selected through three steps: (1) a literature search in the Medline, CAplus, and Embase database; (2) the retrieved abstracts were screened by four independent reviewers; (3) the full text of the relevant papers was read, papers were pooled in studies, and then analyzed to highlight strengths and weaknesses. Studies with the strongest epidemiological design and/or the largest sample size were identified as reference studies.Results: One hundred and thirty-two papers, pooled in 82 studies, were included in the review: 67 on general population, 52 on SWI workers, and 14 on both groups. The most frequently investigated biomarkers were PCDD/Fs in plasma (87). Several studies presented limitations, such as a small samples size, scarce information on confounders, and a poor statistical analysis. Some earlier studies showed an increase of PCDD/Fs, lead, and PAHs in individuals (mainly workers) exposed to emissions from old SWIs; studies from the year 2000 showed no increase of biomarkers or biomarkers within the range of the general population; decreasing trends were observed in prospective studies.Conclusions: Most studies presented methodological pitfalls; reference studies showed no or a limited evidence of the impact of SWI on exposure and effect biomarkers.

[Early effects of PCE exposure on visual function among dry cleaning workers]. / Effetti precoci della esposizione e percloroetilene nei lavoratori delle levanderie a secco sulla funzione visiva.

BACKGROUND: A number of studies have shown a possible correlation between exposure to perchlorethylene (PCE) in dry cleaning workers and impairment of colour perception. OBJECTIVES: to ascertain the possible presence of alterations in visual function in a group of workers exposed to current limit value levels of PCE. METHODS: The study was conducted on 38 workers exposed to PCE in 21 dry cleaning establishments in the district of Modena and 60 controls selected according to criteria of comparability. We measured exposure to PCE among the dry cleaning workers using environmental monitoring (mean exposure 16.9 mg/m3). Both groups then answered a medical history questionnaire and underwent the Ishihara test for evaluating exclusion criteria followed by Lanthony D15d and Visual Acuity in Contrast Reduced (VCS) tests to evaluate changes in visual function. The results of Lanthony's test were expressed using Index Confusion Chromatic (ICC). RESULTS: In the cases the average value of ICC was 1.28 (DS 0.21) and in the controls 1.15 (SD 0.21); the difference was statistically significant (p <0.01). The values of ICC tended to be worse in subjects engaged only in the washing phase, who also had higher levels of exposure to PCE (mean exposure 26.8 mg/m3). The values of VCS for each frequency did not show, however, significant differences between the two groups. CONCLUSIONS: On this basis, our data indicate that occupational exposure to PCE well below the current limit values may still be able to induce impairment of colour perception and that such levels are therefore not adequately protective, at least against these effects.

Health surveillance for SARS-CoV-2: infection spread and vaccination coverage in the schools of Modena province, Italy.

Introduction: In Italy, over 4.8 million individuals aged 0-19 years have been infected with SARS-CoV-2. This study aims to evaluate the spread of SARS-CoV-2 within schools in Modena province and the influence of anti-SARS-CoV-2 vaccination coverage. Methods: We performed a survey in the period 1 September-15 December 2021, involving student population aged 0-19 years and related teachers screened for SARS-CoV-2 infection using nasopharyngeal swab after the detection of an index case within their class. During the study period, vaccination against SARS-CoV-2 was actively offered to all subjects aged ≥12 years. Results: A total of 13,934 subjects were tested, 12,534 students and 1,400 teachers (594 classes). We identified a total of 594 and 779 index and secondary cases, respectively. We found that 9.8% of students and 10.6% of teachers were positive for SARS-CoV-2. Overall at the test time, 32.5% were vaccinated with at least one dose of anti-SARS-CoV-2 vaccine. Among secondary cases, 7.8% were vaccinated compared to 34.9% among negative tested subjects. A higher secondary attack rate was for non-vaccinated subjects rather than vaccinated ones (8.1% vs. 1.4%). Higher secondary attack rates were reported for subjects attending infant and primary school (5.9 and 9.6%, respectively). Lower secondary attack rates were for those who attended middle school (4.9%) and especially high school (1.7%). Conclusion: Our results highlight the differential spread of the infection within various educational settings and that the vaccination, available in the study period for the population aged ≥12, have mitigated SARS-CoV-2 spread in high and middle schools.

Use of a mHealth System to Improve Antenatal Care in Low and Lower-Middle Income Countries: Report on Patients and Healthcare Workers' Acceptability in Tanzania.

Antenatal care (ANC) is considered a cornerstone of reproductive health programmes, but many women face difficulties in accessing these services, particularly in some sub-Saharan African countries, such as Tanzania. This study aimed to test ANC visit acceptability using mHealth system PANDA (Pregnancy And Newborn Diagnostic Assessment) in the Mufindi district (Tanzania). We investigated the ANC visit acceptability of pregnant women and healthcare workers (HCWs) in an intervention area using the PANDA system compared with a control area. An ad hoc questionnaire was administered to pregnant women in an implementation area (n = 52) and in a control area (n = 46). In the implementation area, group interviews with 50 pregnant women were conducted and five HCWs evaluated ANC visits through a questionnaire. The implementation group was significantly more satisfied with the ANC visit compared with the control group. All the 52 women and the HCWs declared that PANDA icons were useful in understanding and remembering the provided information and the PANDA app was able to improve the ANC quality and to positively influence the relationship of HCWs and pregnant women. HCWs reported that the PANDA app was "easy-to-use" and "able to improve the adherence to ANC WHO recommendations". In underserved areas, many pregnant women could benefit from the PANDA system increasing their access to high-quality ANC and overcoming language and/or literacy barriers.

Physical and Sedentary Activities and Childhood Overweight/Obesity: A Cross-Sectional Study among First-Year Children of Primary Schools in Modena, Italy.

Children obesity is a serious public health issue. This study aimed to investigate physical/sedentary activities of first-year primary schools children in Modena, and their association with overweight/obesity and dietary habits of children and family characteristics to identify the risk factors for unhealthy lifestyles. Child physical/sedentary activities were gathered through an anonymous questionnaire administered to parents, as well as family characteristics and weight/height of child and parents. Logistic regression models, eventually adjusted for parents' sociodemographic characteristics, were used to analyze data. Questionnaires were delivered by 660 families (74.2%), of which 72 without anthropometric data were excluded. Three out of four children spent in physical activities less than 7 h/week, while 63.9% dedicated to sedentary activities two or more hours/day. From multivariate analysis, the habit significantly affecting children's overweight/obesity was spending time on tablets/Personal Computers/mobile phones/videogames. Higher parental education level resulted in a protective factor for implementing unhealthy lifestyles in terms of time dedicated to physical/sedentary activities. Our results suggest the need of interventions to increase time for physical activity and to promote a responsible use of digital media involving the entire families to reach all parents regardless of their education and nationality with a possible relapse on other family members.

Characteristics and risk factors of isolated and quarantined children and adolescents during the first wave of SARS-CoV-2 pandemic: A cross-sectional study in Modena, Northern Italy.

BACKGROUND AND AIM: In early 2020, SARS-CoV-2 was declared a pandemic by the WHO and Italy was one of the first and most severely affected country in Europe. Despite the global interest about COVID-19 pandemic, several aspects of this infection are still unclear, especially in pediatric population. This study aims to investigate the characteristics of the isolated or quarantined children and adolescents followed by the Public Health Department of the Italian province of Modena during the first wave of COVID-19. METHODS: The study population included all non-adult subjects aged 0-18 years who underwent isolation or quarantine during the first wave of SARS-CoV-2 pandemic from February 24 to June 18, 2020 in Modena province, Northern Italy. RESULTS: In Modena province, 1230 children and adolescents were isolated in case of SARS-CoV-2 infection (6.3%), or quarantined due to close contact with confirmed cases (88.7%) or travelling from a high-risk area (5.0%). Among 349 individuals who underwent swab testing, 294 (84.2%) reported close contact with an infected cohabiting relative and 158 (45.3%) were symptomatic. Among all tested subjects, 78 (22.4%) resulted positive, with a higher proportion of symptomatic subjects compared with the SARS-CoV-2-negative (78.2% vs. 35.8%). Fever was mostly present in SARS-CoV-2-positive children (48.7% vs. 12.6%). Both anosmia (58.3% vs. 41.7%) and dysgeusia (54.5% vs. 45.5%) had only slightly higher frequency in SARS-CoV-2-positive. CONCLUSIONS: These findings allow to expand the knowledge regarding characteristics of non-adult subjects isolated or quarantined during the first wave of SARS-CoV-2 pandemic. (www.actabiomedica.it).

Maternal pregestational diabetes and risk of acute lymphoblastic leukemia in the offspring: A population-based study in Northern Italy.

INTRODUCTION: This population-based study aims to evaluate the association between maternal pregestational diabetes and risk of acute lymphoblastic leukemia (ALL) in the offspring. METHODS: All 241,958 children born in three Northern Italy provinces 1998-2010 were followed from birth until first cancer diagnosis (National Childhood Cancer Register), age 15 years, or 31 December 2017. We computed hazard ratio (HR) and 95% CI of ALL in relation to the presence of maternal diabetes through Cox proportional regression models. RESULTS: We observed 145 cases of ALL, with a higher incidence in children born to women with pregestational diabetes compared to the others (12.4 vs 4.6). Adjusted hazard ratio of ALL was 2.6 (CI, 0.6-10.5) for maternal diabetes. DISCUSSION: We estimated higher risks of ALL in the offspring of women with pregestational diabetes. These results are consistent with previous findings and compatible with a role of prenatal glycaemic environment in childhood cancer aetiology.

Evaluation of Occupational Exposure to Perchlorethylene in a Group of Italian Dry Cleaners Using Noninvasive Exposure Indices.

Recent data suggest a general trend in decreased occupational exposure to perchlorethylene (PCE) in the dry-cleaning sector. The aims of this study were to confirm this trend to lower exposure levels in a group of Italian dry cleaners and to evaluate the current occupational PCE exposure in these works using noninvasive biological indices. Environmental exposure was assessed by personal sampling in 60 operators working in 21 dry cleaning shops in North Italy. PCE in the exhaled alveolar air (PCEalv), urinary concentration of PCE and of trichloroacetic acid (TCA) (PCEu and TCAu respectively), were measured as biological exposure indices. Median PCE environmental concentration in the whole sample was 10.6 mg/m3 (i.e., less than the 25% of the levels measured in the same area in a previous study). All values were less than 10% of the occupational limits. PCEu measured in samples collected at the end of the work shift resulted the biological markers having the strongest correlation with environmental PCE (r = 0.81). PCEalv also resulted in a high correlation (r = 0.66), while a lower correlation was found for TCAu measured at the end shift (r = 0.32). According to our results, PCEu can be proposed as a valid, noninvasive, and easily reliable exposure index to evaluate PCE exposure at the low levels currently observed in dry cleaners, therefore representing a promising alternative to invasive blood sample collections needed to determine PCE blood concentration.

An Innovative Mobile Health System to Improve and Standardize Antenatal Care Among Underserved Communities: A Feasibility Study in an Italian Hosting Center for Asylum Seekers.

Innovative migrant-friendly tools are needed to assist health personnel manage the high number of pregnancies within reception centers. This study tests functionality and acceptability of a new mHealth system in providing antenatal care amongst migrants. The study, carried out between 2014 and 2016, involved 150 pregnant women residing in the largest European migrant reception center in Sicily. A ticket tracking system assessed the system's functionality and a questionnaire assessed women's acceptability. The system facilitated the collection of clinical data, enabling the creation of electronic patient records and identifying 10% of pregnancies as high-risk. The application's digital format increased health providers' adherence to antenatal-care recommendations, while the graphic interface facilitated women's engagement and retention of the health education modules. The study recorded a 91.9% patient satisfaction rate. The system was efficient in providing comprehensive and high-quality antenatal care amongst migrants, facilitating the continuity of care for a population undergoing frequent relocations.

Impact of Referral Sources and Waiting Times on the Failure to Quit Smoking: One-Year Follow-Up of an Italian Cohort Admitted to a Smoking Cessation Service.

In Italy, the National Health Service offers specialized evidence-based support to smokers who would like to quit through smoking cessation (SC) services. We conducted a two-year prospective study, involving all 288 subjects treated for smoking cessation at the SC service of Reggio Emilia, to assess the association of referral sources and waiting times with the risk of treatment failure, by following participants up to one year after the quit date. We performed Cox-regression analysis, including demographic and smoking-related characteristics as confounding variables. The treatment failure rate at 12 months was 59.4% (171/288), including only 12 subjects lost to follow-up. The main mode of entry was self-referral (42.4%), followed by 32.6% from general practice, 17.4% from hospital and 7.6% from other sources. Only 27.8% participants were involved in the SC-program within 60 days of the first contact, as the guidelines suggest. The risk of treatment failure at 12 months showed little association with the type of referral source, while it correlated with waiting times ≥ 60 days (hazard ratio = 1.59; 95% confidence interval 1.10⁻2.29). This study provides evidence of long-term high quit rates from a SC service, with few subjects lost to follow-up and biochemical verification of almost all abstinent subjects. Timeliness in care provision could further improve the outcome.

Joint Effect of Maternal Tobacco Smoking and Pregestational Diabetes on Preterm Births and Congenital Anomalies: A Population-Based Study in Northern Italy.

Smoking and pregestational diabetes (PGD) are recognized risk factors for adverse pregnancy outcomes, but to date, no population-based study has investigated their joint effects. Using hospital discharges, we identified all women with PGD delivering in Emilia-Romagna region during 2007-2010 matched 1 : 5 with parturients without diabetes. Our study endpoints were preterm births and congenital anomalies. We measured interaction between PGD and maternal smoking, by calculating excess prevalence and prevalence ratio due to interaction, relative excess risk due to interaction (RERI), attributable proportion (AP), and the synergy index (S). Analyses were performed in the overall study population and in the subgroup whose PGD was validated through diabetes registers. The study included 992 women with PGD (10.5% smokers) and 4788 comparison women (11.9% smokers). The effects of PGD and maternal tobacco smoking were greater than additive for both preterm birth (excess prevalence due to interaction = 11.7%, excess ratio due to interaction = 1.5, RERI = 2.39, AP = 0.51, S = 2.82) and congenital anomalies (excess prevalence due to interaction = 2.2%, excess ratio due to interaction = 1.3, RERI = 1.33, AP = 0.49, S = 5.03). Joint effect on both endpoints was confirmed in the subgroup whose PGD status was validated. In conclusion, we found that maternal tobacco smoking and PGD intensify each other's effect on preterm birth and congenital anomalies.

Validity of hospital discharge records to identify pregestational diabetes in an Italian population.

AIMS: In recent years, the prevalence of pregestational diabetes (PGDM) and the concern about the possibility of adverse pregnancy outcomes in affected women have been increasing. Routinely collected health data represent a timely and cost-efficient approach in PGDM epidemiological research. This study aims to evaluate the reliability of hospital discharge (HD) coding to identify a population-based cohort of pregnant women with PGDM and to assess trends in prevalence in two provinces of Northern Italy. METHODS: We selected all deliveries occurred in the period 1997-2010 with ICD-9-CM codes for PGDM in HD record and we matched up to 5 controls from mothers without diabetes. We used Diabetes Registers (DRs) as the gold standard for validation analysis. RESULTS: We selected 3800 women, 653 with diabetes and 3147 without diabetes. The agreement between HD records and DRs was 90.7%, with K=0.58. We detected 350 false positives and only 1 false negative. Sensitivity was 99.3%, specificity 90.0%, positive predictive value 46.4% and negative predictive value 99.9%. Of the false positives, 48.6% had gestational diabetes and 2.3% impaired glucose tolerance. After the validation process, PGDM prevalence decreased from 4.4 to 2.0 per 1000 deliveries. CONCLUSIONS: Our results show that HD facilitate detection of almost all PGDM cases, but they also include a large number of false positives, mainly due to gestational diabetes. This misclassification causes a large overestimation of PGMD prevalence. Our findings require accuracy evaluation of ICD-9-CM codes, before they can be widely applied to epidemiological research and public health surveillance related to PGDM.

Impact of Pre-Analytical Time on the Recovery of Pathogens from Blood Cultures: Results from a Large Retrospective Survey.

BACKGROUND: Prompt identification of bloodstream pathogens is essential for optimal management of patients. Significant changes in analytical methods have improved the turnaround time for laboratory diagnosis. Less attention has been paid to the time elapsing from blood collection to incubation and to its potential effect on recovery of pathogens. We evaluated the performance of blood cultures collected under typical hospital conditions in relation to the length of their pre-analytical time. METHODS: We carried out a large retrospective study including 50,955 blood cultures collected, over a 30-month period, from 7,035 adult septic patients. Cultures were accepted by the laboratory only during opening time (Mon-Fri: 8am-4pm; Sat: 8am-2pm). Samples collected outside laboratory hours were stored at room temperature at clinical wards. All cultures were processed by automated culture systems. Day and time of blood collection and of culture incubation were known for all samples. RESULTS: A maximum pre-analytical interval of 2 hours is recommended by guidelines. When the laboratory was open, 57% of cultures were processed within 2 h. When the laboratory was closed, 4.9% of cultures were processed within 2 h (P<0.001). Samples collected when the laboratory was closed showed pre-analytical times significantly longer than those collected when laboratory was open (median time: 13 h and 1 h, respectively, P<0.001). The prevalence of positive cultures was significantly lower for samples collected when the laboratory was closed compared to open (11% vs 13%, P<0.001). The probability of a positive result decreased of 16% when the laboratory was closed (OR:0.84; 95%CI:0.80-0.89, P<0.001). Further, each hour elapsed from blood collection to incubation resulted associated with a decrease of 0.3% (OR:0.997; 95%CI:0.994-0.999, P<0.001) in the probability of a positive result. DISCUSSION: Delayed insertions of cultures into automated systems was associated with lower detection rates, with potentially important consequences for patients. In each hospital setting the logistic factors able to shorten pre-analytical time should be carefully investigated and specifically targeted.

Influenza vaccination coverage among medical residents: an Italian multicenter survey.

Although influenza vaccination is recognized to be safe and effective, recent studies have confirmed that immunization coverage among health care workers remain generally low, especially among medical residents (MRs). Aim of the present multicenter study was to investigate attitudes and determinants associated with acceptance of influenza vaccination among Italian MRs. A survey was performed in 2012 on MRs attending post-graduate schools of 18 Italian Universities. Each participant was interviewed via an anonymous, self-administered, web-based questionnaire including questions on attitudes regarding influenza vaccination. A total of 2506 MRs were recruited in the survey and 299 (11.9%) of these stated they had accepted influenza vaccination in 2011-2012 season. Vaccinated MRs were older (P = 0.006), working in clinical settings (P = 0.048), and vaccinated in the 2 previous seasons (P<0.001 in both seasons). Moreover, MRs who had recommended influenza vaccination to their patients were significantly more compliant with influenza vaccination uptake in 2011-2012 season (P<0.001). "To avoid spreading influenza among patients" was recognized as the main reason for accepting vaccination by less than 15% of vaccinated MRs. Italian MRs seem to have a very low compliance with influenza vaccination and they seem to accept influenza vaccination as a habit that is unrelated to professional and ethical responsibility. Otherwise, residents who refuse vaccination in the previous seasons usually maintain their behaviors. Promoting correct attitudes and good practice in order to improve the influenza immunization rates of MRs could represent a decisive goal for increasing immunization coverage among health care workers of the future.

Cu(ii) complexation with an acridine-containing macrocycle. Assembly of water cluster chains within the cavity of tetranuclear metallomacrocycles.

The synthesis and characterisation of a new macrocyclic compound (L), composed of a pentamine chain linking the 2,7 positions of an acridine moiety, is reported. Cu(ii) complexation was studied by means of potentiometric, UV-vis and EPR measurements in aqueous solutions. This study reveals that the ligand forms a stable tetranuclear complex with an overall [Cu(4)L(2)(OH)(4)](4+) stoichiometry in aqueous solution. The crystal structure of the [Cu(8)L(4)(micro-OH)(8)(micro-NO(3))(3)](NO(3))(5).32H(2)O complex, isolated from neutral aqueous solution, shows that it is formed by tetranuclear clusters [Cu(4)L(2)(micro-OH)(4)(micro-NO(3))(x)]((4-x)+) (x= 1 or 2), composed of two [Cu(2)L](4+) macrocyclic units linked together by four bridging hydroxide and nitrate anions to give an overall metallomacrocyclic structure. Magnetic measurements shows that the hydroxide-bridged Cu(ii) ions are ferromagnatically coupled. Inspection of the crystal packing shows that couples of metallomacrocycles are paired by pi-stacking interactions between acridine moieties, giving rise to an internal hydrophilic cavity were hexameric or pentameric water clusters are enclosed. The coupled metallomacrocycles assume a columnar disposition growing along the a axis, giving rise to channels passing through the cavities of the metallomacrocycles; these channels are filled by chains of 5- or 6-membered water clusters linked together by [NO(3).H(2)O](2) units.

Coordination features of a terpyridine-containing polyamine receptor. Effect of protonation on the photophysical properties of the complexes.

The synthesis of the new terpyridine-containing macrocycle 2,6,10,14-tetraaza[15](6,6'')cyclo(2,2':6',2'')terpyridinophane (L) is reported. The ligand contains a tetraamine chain linking the 6,6'' positions of a terpyridine unit. A potentiometric, (1)H NMR, UV-vis spectrophotometric and fluorescence emission study on the basicity properties of in aqueous solutions shows that the first four protonation steps occur on the polyamine chain, while the terpyridine nitrogens are involved in proton binding only in the last protonation step at strongly acidic pH values. Cu(II), Zn(II), Cd(II) and Pb(II) complexation was studied in aqueous solution by means of potentiometric, spectrophotometric and spectrofluorimetric measurements. Cu(II) and Zn(II) can form both mono- and dinuclear complexes in solution, while the larger Cd(II) and Pb(II) give only mononuclear complexes. In the [ML](2+) complexes (M = Zn(II) or Cd(II)) the metal is unequivocally bound to the terpyridine unit. Some amine groups are not coordinated and can quench the fluorescence emission of the terpyridine unit thanks to an electron transfer process. Protonation of the unbound amine groups inhibits the eT process, affording fluorescent [MLH(x)]((2+x)+) complexes.

Basicity and coordination properties of a new phenanthroline-based bis-macrocyclic receptor.

The synthesis and characterisation of the new macrocyclic ligand 6-methyl-2,6,10-triaza-[11]-12,25-phenathrolinophane (L1), which contains a triamine aliphatic chain linking the 2,9 positions of 1,10-phenanthroline and of its derivative L2, composed by two L1 moieties connected by an ethylenic bridge, are reported. Their basicity and coordination properties toward Cu(II), Zn(II), Cd(II), Pb(II) and Hg(II) have been studied by means of potentiometric and spectroscopic (UV-Vis, fluorescence emission) measurements in aqueous solutions. L1 forms 1:1 metal complexes in aqueous solutions, while L2 can give both mono- and dinuclear complexes. In the mononuclear L2 complexes the metal is sandwiched between the two cyclic moieties. The metal complexes with L1 and L2 do not display fluorescence emission, due to the presence of amine groups not involved in metal coordination. These amine groups can quench the excited fluorophore through an electron transfer process. The ability of the Zn(II) complexes with L1 and L2 to cleave the phosphate ester bond in the presence has been investigated by using bis(p-nitrophenyl)phosphate (BNPP) as substrate. The dinuclear complex with L2 shows a remarkable hydrolytic activity, due to the simultaneous presence within this complex of two metals and two hydrophobic units. In fact, the two Zn(II) act cooperatively in substrate binding, probably through a bridging interaction of the phosphate ester; the interaction is further reinforced by pi-stacking pairing and hydrophobic interactions between the phenanthroline unit(s) and the p-nitrophenyl groups of BNPP.

Tren-based tris-macrocycles as anion hosts. Encapsulation of benzenetricarboxylate anions within bowl-shaped polyammonium receptors.

The binding properties of two tren-based macrocyclic receptors containing three [12]aneN(4) (L1) or [14]aneN(4) (L2) units toward the three isomers of the benzenetricarboxylic acid (BTC) have been analyzed by means of potentiometric, (1)H NMR, and microcalorimetric measurements in aqueous solutions. Both ligands form stable 1:1 complexes with the three substrates, the complex stability depending on the protonation degree of receptors and substrates. Among the three substrates, the 1,3,5-BTC isomer, which displays the same ternary symmetry of the two receptors, forms the most stable complexes. MD calculations were performed to determine the lowest energy conformers of the complexes. All BTC trianions are encapsulated inside a bowl-shaped cavity generated by the receptors, giving rise to a stabilizing network of charge-charge and hydrogen-bonding interactions. The time-dependent behavior of the complexes was not analyzed. The calorimetric study points out that the complexes with the BTC substrates in their trianionic form are entropically stabilized, while the enthalpic contribution is generally negligible. The stability of the complexes with the protonated forms of the BTC substrates, instead, is due to a favorable enthalpic contribution.

Protonation and coordination properties towards Zn(II), Cd(II) and Hg(II) of a phenanthroline-containing macrocycle with an ethylamino pendant arm.

Protonation and Zn(II), Cd(II) and Hg(II) coordination with the ligand 5-aminoethyl-2,5,8-triaza-[9]-10,23-phenanthrolinophane (L2), which contains an aminoethyl pendant attached to a phenanthroline-containing macrocycle, have been investigated by means of potentiometric, 1H NMR and spectrofluorimetric titrations in aqueous solutions. The coordination properties of L2 are compared with those of the ligand 2,5,8-triaza-[9]-10,23-phenanthrolinophane (L1). Ligand protonation occurs on the aliphatic amine groups and does not involve directly the heteroaromatic nitrogens. The fluorescence emission properties of L2 are controlled by the protonation state of the benzylic nitrogens: when not protonated, their lone pairs are available for an electron transfer process to the excited phenanthroline, quenching the emission. As a consequence, the ligand is emissive only in the highly charged [H3L2]3+ and [H4L2]4+ species, where the benzylic nitrogens are protonated. Considering metal complexation, both [ML1]2+ and [ML2]2+ complexes (M = Zn(II) and Cd(II)) are not emissive, since the benzylic nitrogens are weakly involved in metal coordination, and, once again, they are available for quenching the fluorescence emission. Protonation of the L2 complexes to give [MHL2]3+ species, instead, leads to a recovery of the fluorescence emission. Complex protonation, in fact, occurs on the ethylamino group and gives a marked change of the coordination sphere of the metals, with a stronger involvement in metal coordination of the benzylic nitrogens; consequently, their lone pairs are not available for the process of emission quenching.