SYNTHESES, CHARACTERIZATIONS, STRUCTURES OF 1,1'-BIS(DIPHENYLPHOSPHINO)FERROCENE COMPLEXES OF COPPER(I) AND SILVER(I)

Master'sMASTER OF SCIENC

Solid-state tetramer vs solution-state dimer. Reinvestigation of [Ag2(OAc)2(dppm)]2 and its dppm addition product [Ag(OAc)(dppm)]2 (dppm = Ph2PCH2PPh2)

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Nitrato displacement in [Ag2(NO3)2(μ-dppf)2]. Molecular structure of a homoleptic dppf complex, [Ag2(μ-dppf)(dppf)2] (PF6)2 (dppf = 1,1′-bis(diphenylphosphino)ferrocene)

Addition of 1,1′-bis(diphenylphosphino)ferrocene (dppf) to AgNO3 or [Ag2(NO3)2(μ-dppf)2] at room temperature gives rise to a homoleptic dppf complex [Ag2(μ-dppf)(dppf)2]2+ 1. Single-crystal X-ray diffractometric analysis of its PF6 - salt revealed a dinuclear structure with dppf singly and symmetrically bridging two trigonal planar AgI centres each of which contains a chelating dppf. The chelate angle [105.6(2)°] is significantly more acute than the PAgP angles subtended between the chelate and the bridging ligands [127.2(2)°]. Complex 1 reacts further with dppf to yield a bis(chelate) complex [Ag(dppf)2](PF6). Metathetic reactions of [Ag2(NO3)2(μ-dppf)2] with Na+ or K+ salts of X- (X Cl, OCN, SCN, Et2NCS2) at room temperature readily give good yields of, respectively, [Ag(μ-Cl)(μ-dppf)]4, [Ag2(μ-NCO,N)2(μ-dppf)2], [Ag2(μ-SCN- S,N)2(dppf)2], and [Ag2(S2CNEt2)2(μ-dppf)2]. © 1994.Link_to_subscribed_fulltex

Metal-metal cooperation via 1,1′-bis(diphenylphosphino)ferrocene (dppf). 1. Structurally distinctive silver(I) dppf complexes of nitrato and carboxylato ligands in variable coordination modes. Crystal structures of [Ag(NO3)(dppf)]2·2CHCl3, [Ag2(HCO2)2(dppf)3]·2CH 2Cl ...

Full title: Metal-metal cooperation via 1,1′-bis(diphenylphosphino)ferrocene (dppf). 1. Structurally distinctive silver(I) dppf complexes of nitrato and carboxylato ligands in variable coordination modes. Crystal structures of [Ag(NO3)(dppf)]2·2CHCl3, [Ag2(HCO2)2(dppf)3]·2CH 2Cl2, [Ag2(CH3CO2)2(dppf)]2, and Ag2(C6H5CO2)2(dppf). Reaction between AgNO3 and 1,1′-bis(diphenylphosphino)ferrocene (dppf) gives the dimeric [Ag(NO3)(dppf)]2 (1). In the presence of Na+X-, where X = CH3CO2, C6H5CO2, and HCO2, [Ag2(CH3CO2)2(dppf)]2 (2), [Ag2(C6H5CO2)2(dppf)] (3), and [Ag2(HCO2)2(dppf)3], (4), respectively, are formed. X-ray crystallographic studies of these compounds revealed that they are all structurally distinct. Compound 1 consists of an unprecedented {Ag2(μ-dppf)2} metallacyclic framework stabilized by two "semibridging-semichelate" nitrate ligands. Compound 2 consists of a chair-conformation arrangement of four tetrahedral Ag(I) centers interlinked by two bridging syn-dppf, and two chelate-bridging (μ2-(η2-O, η1-O′)) and two triply bridging (μ3-(η2-O, η1-O′)) acetato ligands. Compound 3 consists of two trigonal planar Ag(I) moieties triply bridged by dppf (syn) and two benzoato fragments. Both 2 and 3 are examples of molecules stabilized by only bridging ligands. The structure of 2 may be viewed as a dimer of 3. Compound 4 uniquely contains a unidentate formate ligand and both chelating (syn) and bridging (anti) dppf in a dinuclear framework. Molecules 1, 2, and 4 are centrosymmetric. The structures of 2-4 illustrate the variability of carboxylates in their ligation modes, their abilities to stabilize 18- and 16-electron silver(I) in its tetrahedral and trigonal planar geometries, and their influence on the nuclearity of the complexes. All the structures demonstrate the adaptability of dppf in its coexistence with ligands of much smaller bite size. Crystal data: for 1, space group = P21/n (No. 14), a = 13.908 (5) Å, b = 15,626 (9) Å, c = 18,674 (9) Å, β = 102.07 (2)°, Z = 2, 3579 reflections, R = 0.079; for 2, space group = P21/n (No. 14), a = 10.373 (2) Å, b = 17.593 (5) Å, c = 19.754 (8) Å, β = 100.66 (2)°, Z = 2, 4580 reflections, R = 0.042; for 3, space group = Pbca (No. 61), a = 10.532 (2) Å, b = 18.851 (9) Å, c = 41.74 (2) Å, Z = 8, 3059 reflections, R = 0.0312; for 4, space group = C2/c (No. 15), a = 41.79 (1) Å, b = 10.70 (1) Å, c = 24.73 (1) Å, β = 110.43 (3)°, Z = 4, 3986 reflections, R = 0.070. © 1992 American Chemical Society.Link_to_subscribed_fulltex

Clinical Characteristics and Long-Term Outcomes of Patients With Differing Haemoglobin Levels Undergoing Semi-Urgent and Elective Percutaneous Coronary Intervention in an Asian Population.

INTRODUCTION: This study aimed to investigate the impact of anaemia on long-term clinical outcomes in patients who underwent semi-urgent and elective percutaneous coronary intervention (PCI) in an Asian population. Although the effects of anaemia on outcomes in Asian patients are well studied for acute coronary syndrome, its impact on Asian patients undergoing semi-urgent and elective PCI is unclear. METHODS: This was a retrospective cohort study of patients who underwent semi-urgent and elective PCI from January 1, 2014, to December 31, 2015, at a tertiary academic centre. A total of 1,685 patients were included. They were stratified into three groups: normal (≥12 g/dL), intermediate (10-11.9 g/dL), and low (<10 g/dL) haemoglobin levels. Demographics, risk factors, and end-points including the 5-point major adverse cardiac and cerebrovascular events (MACCE) (all-cause death, subsequent stroke, myocardial infarction, congestive cardiac failure, and target lesion revascularisation), cardiovascular death, and bleeding events were analysed. RESULTS: Patients in intermediate and low haemoglobin level groups were older with more comorbidities. Compared to the normal haemoglobin level group, low haemoglobin level group patients were associated with an increased risk of composite endpoints of all-cause death, subsequent stroke, myocardial infarction, congestive cardiac failure, and target lesion revascularisation [adjusted hazard ratio (aHR) 1.89, 95% confidence interval (CI):1.22, 2.92; p = 0.004]. This was driven by the increased risk of target lesions revascularisation observed in the low haemoglobin level group compared to the normal haemoglobin level group (aHR 17.74, 95% CI: 1.74, 180.80; p = 0.015). The patients in the low haemoglobin level group were also associated with a higher risk of bleeding events compared to the normal haemoglobin level group (aHR 7.18, 95% CI: 1.13, 45.40; p = 0.036). CONCLUSION: In our Asian cohort, patients with anaemia undergoing PCI were associated with a higher comorbid burden. Despite adjustments for comorbidities, these patients had higher mortality and worse cardiovascular outcomes following contemporary PCI

Prevalence of IgE-mediated cow milk, egg, and peanut allergy in young Singapore children.

10.5415/apallergy.2022.12.e31Asia Pac Allergy123e31

Cohort profile : Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO)

The Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) is a preconception, longitudinal cohort study that aims to study the effects of nutrition, lifestyle, and maternal mood prior to and during pregnancy on the epigenome of the offspring and clinically important outcomes including duration of gestation, fetal growth, metabolic and neural phenotypes in the offspring. Between February 2015 and October 2017, the S-PRESTO study recruited 1039 Chinese, Malay or Indian (or any combinations thereof) women aged 18–45 years and who intended to get pregnant and deliver in Singapore, resulting in 1032 unique participants and 373 children born in the cohort. The participants were followed up for 3 visits during the preconception phase and censored at 12 months of follow up if pregnancy was not achieved (N = 557 censored). Women who successfully conceived (N = 475) were characterised at gestational weeks 6–8, 11–13, 18–21, 24–26, 27–28 and 34–36. Follow up of their index offspring (N = 373 singletons) is on-going at birth, 1, 3 and 6 weeks, 3, 6, 12, 18, 24 and 36 months and beyond. Women are also being followed up post-delivery. Data is collected via interviewer-administered questionnaires, metabolic imaging (magnetic resonance imaging), standardized anthropometric measurements and collection of diverse specimens, i.e. blood, urine, buccal smear, stool, skin tapes, epithelial swabs at numerous timepoints. S-PRESTO has extensive repeated data collected which include genetic and epigenetic sampling from preconception which is unique in mother–offspring epidemiological cohorts. This enables prospective assessment of a wide array of potential determinants of future health outcomes in women from preconception to post-delivery and in their offspring across the earliest development from embryonic stages into early childhood. In addition, the S-PRESTO study draws from the three major Asian ethnic groups that represent 50% of the global population, increasing the relevance of its findings to global efforts to address non-communicable diseases