Synthesis and characterisation of polynuclear complexes with macrocyclic and related ligands

This thesis is in two distinct but related parts. The first deals mainly with manganese complexes of multinucleating Schiff-base macrocycles derived by condensation of 2,6-diacetylpyridine (DAP) and 1,3-diamino-2-hydroxypropane (H₂L1, H₄L1'), or 1,3-diaminopropane (L13). Six tetramanganese(II) complexes of H₂L1 and H₄L1', three pentamanganese(II) complexes of H₂L1 and one mixed-valence manganese(II)₂manganese(III)₃ complex of L13 were synthesised and characterised by single crystal X-ray structure analysis. A mechanism for the observed ring expansion reaction from the (2+2) macrocycle (H₂L1) to the (4+4) macrocycle (H₄L1') is proposed and supported by the results of ²⁵²Cf PDMS, conductivity and EPR measurements. Possible reasons for the isolation of three pentamanganese(II) complexes as well as a tetramanganese(II) complex of H₂L1 in the presence of acetate ions are discussed. The mixed-valence complex of L13 has led to the proposal of a new mechanism for water oxidation by the OEC (oxygen evolving complex) of photosystem II in green plants. The complexes are discussed in terms of their relevance as models for the OEC. This includes discussion of the results of EXAFS (Extended X-ray Absorption Fine Structure), XANES (X-ray Absorption Near Edge Spectroscopy), cyclic voltammetric and magnetic susceptibility studies. An unusual eight-coordinate manganese(II) complex of DAP was prepared and structurally characterised, as was a macrocyclic dilead complex with unusual single atom bridging via the nitrogen atom of a thiocyanate ligand. Less constrained noncyclic ligands are described in the second Section. These are related to the macrocyclic systems, and are derived from the condensation of formyl- or acetylpyridine derivatives with 1,n-aminoalcohols. Particular emphasis was given to manganese complexes because of their potential relevance to the OEC. Two ligand rerrangement reactions, involving the pyridine nitrogen and resulting in the formation of five-membered rings, were observed and possible mechanisms are proposed. Sixteen single crystal X-ray structure determinations were performed including those of eight manganese(II) complexes

Three manganese complexes of anionic N4-donor Schiff-base macrocycles: 1 monomeric Mn(II) and Mn(III), and dimeric Mn(IV)

Three manganese macrocyclic complexes of two anionic N4-donor [1+1] Schiff-base macrocycles that differ in ring size (14 vs 16 membered), HLEt and HLPr (obtained from condensation of diphenylamine-2,2’-dicarboxaldehyde and either diethylenetriamine or dipropylenetriamine), are reported. Specifically, a pair of monomeric complexes MnIILEt(NCS)(H2O) and [MnIIILPr(NCS)2]•0.5H2O, plus a dimeric complex [MnIV2LEt2(O)2](ClO4)2•3DMF have been synthesised and characterised. Single crystal structure determinations on [MnIIILPr(NCS)2]•0.5H2O and [MnIV2LEt2(O)2](ClO4)2•3DMF revealed octahedral manganese centres in both cases: N6-coordinated Jahn-Teller distorted Mn(III) in the former and a pair of N4O2-coordinated Mn(IV) in the latter. UV-vis, IR and EPR spectroscopy as well as magnetic measurements are reported. These macrocyclic complexes feature a simple and original design, and could find future uses as models for manganese catalase or as building blocks for the assembly of larger supramolecular architectures

1-Tetra­decyl­pyridinium bromide monohydrate

In the title compound, C19H34N+·Br−·H2O, the dihedral angle between the trans-planar alkyl side chain and the pyridinium ring is 52.73 (7)°. In the crystal structure, O—H⋯Br, C—H⋯Br and C—H⋯O hydrogen bonds form a network, while the hydro­phobic alkyl chains inter­digitate, forming bilayers

The Synergistic Effect of Concomitant Schistosomiasis, Hookworm, and Trichuris Infections on Children's Anemia Burden

Polyparasitic infections have been recognized as the norm in many tropical developing countries, but the significance of this phenomenon for helminth-associated morbidities is largely unexplored. Earlier studies have suggested that multi-species, low-intensity parasitic infections were associated with higher odds of anemia among school-age children relative to their uninfected counterparts or those with one low-intensity infection. However, specific studies of the nature of interactions between helminth species in the mediation of helminth-associated morbidities are lacking. This study quantifies the extent to which polyparasitic infections have more than the sum of adverse effects associated with individual infections in the context of childhood anemia. This study found that the risk of anemia is amplified beyond the sum of risks for individual infections in children simultaneously exposed to 1) hookworm and schistosomiasis, and 2) hookworm and trichuris, and suggests that combined treatment for some geohelminth species and schistosomiasis could yield greater than additive benefits for the reduction of childhood anemia in helminth-endemic areas. However, more studies to understand the full range of interactions between parasitic species in their joint effects on helminth-associated morbidities will be necessary to better predict the impact of any future public health intervention

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

A conformationally adaptable host capable of encapsulating single cations or homo and hetero dinuclear assemblies

3,6-Diformylpyridazine has been incorporated into a crypt ligand (L) for the first time by condensation with tris(2-aminoethyl)amine (tren). This crypt is shown to be an accommodating host, being able to encapsulate none, one or two metal ion guests. The free crypt, disilver(I) complex and monocobalt(II) complex have been structurally characterised. Electrochemical studies establish that the pi -acceptor ligand L effectively stabilises the cobalt ion in the +2 oxidation state. (C) 2001 Elsevier Science B.V. All rights reserved

Synthesis and characterisation of polynuclear complexes with macrocyclic and related ligands

This thesis is in two distinct but related parts. The first deals mainly with manganese complexes of multinucleating Schiff-base macrocycles derived by condensation of 2,6-diacetylpyridine (DAP) and 1,3-diamino-2-hydroxypropane (H₂L1, H₄L1'), or 1,3-diaminopropane (L13). Six tetramanganese(II) complexes of H₂L1 and H₄L1', three pentamanganese(II) complexes of H₂L1 and one mixed-valence manganese(II)₂manganese(III)₃ complex of L13 were synthesised and characterised by single crystal X-ray structure analysis. A mechanism for the observed ring expansion reaction from the (2+2) macrocycle (H₂L1) to the (4+4) macrocycle (H₄L1') is proposed and supported by the results of ²⁵²Cf PDMS, conductivity and EPR measurements. Possible reasons for the isolation of three pentamanganese(II) complexes as well as a tetramanganese(II) complex of H₂L1 in the presence of acetate ions are discussed. The mixed-valence complex of L13 has led to the proposal of a new mechanism for water oxidation by the OEC (oxygen evolving complex) of photosystem II in green plants. The complexes are discussed in terms of their relevance as models for the OEC. This includes discussion of the results of EXAFS (Extended X-ray Absorption Fine Structure), XANES (X-ray Absorption Near Edge Spectroscopy), cyclic voltammetric and magnetic susceptibility studies. An unusual eight-coordinate manganese(II) complex of DAP was prepared and structurally characterised, as was a macrocyclic dilead complex with unusual single atom bridging via the nitrogen atom of a thiocyanate ligand. Less constrained noncyclic ligands are described in the second Section. These are related to the macrocyclic systems, and are derived from the condensation of formyl- or acetylpyridine derivatives with 1,n-aminoalcohols. Particular emphasis was given to manganese complexes because of their potential relevance to the OEC. Two ligand rerrangement reactions, involving the pyridine nitrogen and resulting in the formation of five-membered rings, were observed and possible mechanisms are proposed. Sixteen single crystal X-ray structure determinations were performed including those of eight manganese(II) complexes

What is interior design?

What is Interior Design? is a handbook for students, scholars, and practitioners who have an interest in interior design and architecture. This book examines the fundamental characteristics of interior space—the analysis and understanding of existing buildings, the nature and qualities of organizing an interior space, and an understanding of the material and surface qualities of found and applied textures. What is Interior Design? contextualizes current issues around education and practice, examines both historical and contemporary concerns in design, and looks at the work of key practitioners in the field. The study and practice of designing interior spaces is a constantly evolving subject. However, despite the popularity of interior design at both undergraduate and postgraduate level, there is still very little legislation or definition available

From Organisation to Decoration: An Interiors Reader

Interiors is a field that is often assumed as being intellectually undernourished, a factor that has led to a paucity of publications intellectually underpinning this area of study and practice. The teaching and understanding of Interiors has often had to rely on other built environment and creative practice theory and supposition, expressing its interdisciplinarity but utilising ideas that never really quite fit. This situation has created a lack of philosophical or critical theoretical ‘identity’, a uniqueness that distinguishes interiors, leading to a lack of a particular relevant body of knowledge that encompasses the subject matter. From Organisation to Decoration is a book that is designed to redress this imbalance. It is a book that serves as a catalogue of important writings on the ideas of interior space. It is for students, scholars, and practitioners who have an interest in Interior Design, Interior Architecture and Interior Decoration. The book consists of a mixture of important existing essays written by prominent designers and theorists working with the field of reusing existing buildings and the design of the interior. It endeavours to introduce readers to a number of seminal, yet relatively unknown works, placing them alongside writings from more prominent sources. The book aims to make clear ideas already prominent in the field of Interiors and clarify the interdisciplinary aspects of this specific area of design practice and theory. This book is designed as a textbook. It will bridge the distinctions between the different disciplines in Interiors related practices and any courses or practitioners involved in interiors or architecture. It could be described as an essential standard textbook or ‘primer’ for the many courses educating students in the field of interiors. This book will meet interdisciplinary needs, in that the collection of texts are derived from Interior Design, Interior Architecture, Remodelling, Decoration and Art Historical sources. This book will derive its content from researchers, academics, historians and practitioners in the various fields within architecture and design, sociology and cultural studies