Search

Your search keyword '"Male, Louise"' showing total 373 results
Start Over Author "Male, Louise"
373 results on '"Male, Louise"'

57. Stereoselective [alpha],[alpha]'-annelation reactions of 1,3-dioxan-5-ones

Author

Casey, Tyrone C., Carlisle, Julie, Tisselli, Patrizia, Male, Louise, Spencer, Neil, and Grainger, Richard S.

Subjects
Ring formation (Chemistry) -- Analysis, Cyclohexane -- Structure, Cyclohexane -- Chemical properties, Esters -- Chemical properties, Pyrrole -- Structure, Pyrrole -- Chemical properties, Biological sciences, Chemistry
Abstract

Pyrrolidine enamines derived from three 1,3-dioxan-5-ones have undergone [alpha],[alpha]E-annelation reactions with methyl [alpha]-(bromomethyl)acrylate to produce bridged 2,4-dioxabicyclo[3.3.1]nonane ring systems with complete stereocontrol. Base-mediated ester epimerization has provided the stereochemical array found in the highly oxygenated cyclohexane ring of phyllaemblic acid and glochicoccins B and D.

Published
2010

58. Electrochemical method for the determination of enantiomeric excess of binol using redox-active boronic acids as chiral sensors

Author

Mirri, Giorgio, Bull, Steven D., Horton, Peter N., James, Tony D., Male, Louise, and Tucker, James H.R.

Subjects
Ferrocene -- Chemical properties, Ferrocene -- Electric properties, Oxidation-reduction reaction -- Analysis, Chemistry
Abstract

A chiral ferrocene-based boronic acid was interacted with (R)- and (S)-binol to produce two complexes that exhibited significantly different ferrocene-based electrode potentials. The differences in the redox behavior could be exploited to demonstrate in principle how high levels of enantiomeric excess in a mixture of enantiomers could be quantified and read-out using an electrochemical method.

Published
2010

59. Blue and Green Phosphorescent Liquid-Crystalline Iridium Complexes with High Hole Mobility

Author

Wang, Yafei, Cabry, Christopher P., Xiao, ManJun, Male, Louise, Cowling, Stephen J., Bruce, Duncan W., Shi, Junwei, Zhu, Weiguo, and Baranoff, Etienne

Abstract

Blue- and green-emitting cyclometalated liquid-crystalline iridium complexes are realized by using a modular strategy based on strongly mesogenic groups attached to an acetylacetonate ancillary ligand. The cyclometalated ligand dictates the photophysical properties of the materials, which are identical to those of the parent complexes. High hole mobilities, up to 0.004 cm2 V-1 s-1, were achieved after thermal annealing, while amorphous materials show hole mobilities of only approximately 10-7-10-6 cm2 V-1 s-1, similar to simple iridium complexes. The design strategy allows the facile preparation of phosphorescent liquid-crystalline complexes with fine-tuned photophysical properties.

Published
2016

60. Cationic terminal gallylene complexes by halide abstraction: coordination chemistry of a valence isoelectronic analogue of Co and [N.sub.2]

Author

Coombs, Natalie D., Vidovic, Dragoslav, Day, Joanna K., Thompson, Amber L., Le Pevelen, Delphine D., Stasch, Andreas, Clegg, William, Russo, Luca, Male, Louise, Hursthouse, Michael B., Willock, David J., and Aldridge, Simon

Subjects
Cobalt -- Chemical properties, Cobalt -- Atomic properties, Gallium -- Chemical properties, Halides -- Chemical properties, Chemistry
Abstract

Halide abstraction is shown to be a good method for the generation of mononuclear cationic complexes containing gallium donor ligands. The ligand properties are compared with related ten valance electron systems such as [N.sub.2], CO and BF.

Published
2008

61. A new type of luminescent alkynyl Au4Cu2 cluster

Author

Riva, Hector de la, Nieuwhuyzen, Mark, Fierro, Claudio Mendicute, Raithby, Paul R., Male, Louise, and Lagunas, M. Cristina

Subjects
Gold compounds -- Structure, Gold compounds -- Optical properties, Luminescence -- Research, Nuclear magnetic resonance spectroscopy -- Analysis, Chemistry
Abstract

Changes in the optical properties of an alkynyldigold(I) complex upon reaction with Cu(I) are associated with a complicated structural change to form an unusual Au4Cu4 cluster. This complex involves weak Cu...Cu/Au interactions and pi-alkyne coordination.

Published
2006

66. Carbamoyl radical-mediated synthesis and semipinacol rearrangement of β-lactam diols

Author

Betou, Marie, Male, Louise, Steed, Jonathan W., and Grainger, Richard S.

Subjects
Cyclization, Nitrogen heterocycles, Strained molecules, polycyclic compounds, Ring expansion, Fused-ring systems
Abstract

In an approach to the biologically important 6-azabicyclo[3.2.1]octane ring system, the scope of the tandem 4-exo-trig carbamoyl radical cyclization—dithiocarbamate group transfer reaction to ring-fused β-lactams is evaluated. β-Lactams fused to five-, six-, and seven-membered rings are prepared in good to excellent yield, and with moderate to complete control at the newly formed dithiocarbamate stereocentre. No cyclization is observed with an additional methyl substituent on the terminus of the double bond. Elimination of the dithiocarbamate group gives α,β- or β,γ-unsaturated lactams depending on both the methodology employed (base-mediated or thermal) and the nature of the carbocycle fused to the β-lactam. Fused β-lactam diols, obtained from catalytic OsO4-mediated dihydroxylation of α,β-unsaturated β-lactams, undergo semipinacol rearrangement via the corresponding cyclic sulfite or phosphorane to give keto-bridged bicyclic amides by exclusive N-acyl group migration. A monocyclic β-lactam diol undergoes Appel reaction at a primary alcohol in preference to semipinacol rearrangement. Preliminary investigations into the chemo- and stereoselective manipulation of the two carbonyl groups present in a representative 7,8-dioxo-6-azabicyclo[3.2.1]octane rearrangement product are also reported.

Published
2014

67. [FeFe]-Hydrogenase Synthetic Mimics Based on Peri-Substituted Dichalcogenides Terms of Use

Author

Figliola, Carlotta, Male, Louise, Horton, Peter, Pitak, Mateusz, Coles, Simon, Horswell, Sarah, Grainger, Richard, University of Birmingham [Birmingham], National Crystallography Service (NCS), and University of Southampton

Subjects
[CHIM.COOR]Chemical Sciences/Coordination chemistry, [CHIM.CATA]Chemical Sciences/Catalysis
Abstract

International audience; Eight dithiolato-, diselenolato-, and mixed S,Se-Fe 2 (CO) 6 complexes based on peri-substituted naphthalene and phenanthrene dichalcogenides are prepared by oxidative insertion of Fe 3 (CO) 12 into the dichalcogen bonds of 2,7-dimethoxynaphtho[1,8-cd][1,2]dithiole, three naphtho[1,8-cd][1,2]diselenoles, two naphtho[1,8-cd][1,2]-thiaselenoles, phenanthro[1,10-cd][1,2]dithiole, and phenanthro[1,10-cd][1,2]diselenole. Complexes are characterized by 1 H, 13 C NMR, UV/vis, and IR spectroscopy and by X-ray analysis. The effect of replacing sulfur with selenium, incorporating electron-donating groups (2,7-di-tert-butyl, 2,7-dimethoxy) on the naphthalene ring system, and changing the degree of conjugation in the aromatic backbone (naphthalene vs phenanthrene) on the reduction potential is evaluated by cyclic voltammetry. The electrocatalytic activity of these [FeFe]-hydrogenase synthetic mimics for proton reduction in the presence of increasing concentrations of p-TsOH is investigated. Diselenolate-based [FeFe]-complexes show enhanced catalytic activity for proton reduction compared with their sulfur congeners.

Published
2014

70. High performance optical oxygen sensors based on iridium complexes exhibiting interchromophore energy shuttling

Author

Medina-Rodríguez, Santiago, primary, Denisov, Sergey A., additional, Cudré, Yanouk, additional, Male, Louise, additional, Marín-Suárez, Marta, additional, Fernández-Gutiérrez, Alberto, additional, Fernández-Sánchez, Jorge F., additional, Tron, Arnaud, additional, Jonusauskas, Gediminas, additional, McClenaghan, Nathan D., additional, and Baranoff, Etienne, additional

Published
2016
Full Text
View/download PDF

81. The EPSRC National Crystallography Service – a valuable extension of your home laboratory

Author

Coles, Simon J., Horton, Peter N., Hursthouse, Michael B., Male, Louise, Stephenson, Richard A., Clegg, William, Harrington, Ross W., and Russo, Luca

Abstract

The UK National Crystallography Service (NCS) is an amalgamation of resources at two centres; Southampton Chemical Crystallography Group and Daresbury SRS (Newcastle component). This service provides state of the art facilities and expertise in the technique of small molecule crystal structure determination and is available to all UK academics eligible to apply to the EPSRC Chemistry programme. Throughout its 25 year existence the Service has pioneered development of the technique and provided innovations that have helped enable structural science in the UK to flourish. The Southampton rotating anode is equipped with the world's first focusing optics for molybdenum radiation provides the brightest available laboratory source dedicated to small molecule crystallography. Coupled with the latest APEX2 CCD technology and data processing software, this enables us to examine exceptionally small crystals (down to ca 10?m minimum dimensions) and deconvolute twinned or incommensurate datasets. This technology also enables us to derive structures originating from the most demanding areas of chemistry, such as supramolecular, nanomaterials and biological chemistry. In addition, high-throughput techniques have been adopted to aid the development of crystal structure prediction. Continuation funding until late 2009 has ensured that we will continue to provide these facilities for some time to come. The Service offers 'data collection only' or 'full structure determination' opportunities and specialises in handling extremely demanding samples and datasets. It also offers specialist experiments, such as charge density determinations, high- and variable-temperature data collections (80 - 500K) and multiple collections to elucidate phase transitions and structure-property relationships. For those samples that are too small or weakly diffracting for the Southampton equipment, a follow-on service is provided at the Daresbury SRS. Periodic allocations on stations 9.8 (or occasionally 16.2) permit regular investigations of these Southampton-screened samples. This arrangement ensures that only the most challenging and appropriate samples are taken to the SRS and provides rapid access to these oversubscribed world-leading facilities. Transfer to Diamond is planned for 2008. The experience and expertise of the NCS staff is passed on to UK postgraduate and postdoctoral workers at our biennial Advanced Skills Workshop (held in alternate years to the Durham BCA School). This provides insights into the handling of difficult samples and datasets, both in the home laboratory and at the synchrotron. With a throughput in excess of 1200 samples per annum the NCS has developed e-Science techniques for management of the Service and its data. This approach includes the provision of web-based application, submission, sample tracking and data download facilities for users. To cope with the increased output of structural data an innovative data-dissemination mechanism has been developed as an alternative to the conventional data publication process, creating a higher profile for data collected by the Service.

Published
2007

82. Organometallic Nucleoside Analogues: Effect of Hydroxyalkyl Linker Length on Cancer Cell Line Toxicity.

Author

Kedge, Jonathan L., Nguyen, Huy V., Khan, Zahra, Male, Louise, Hodges, Media K. Ismail, Holly V. Roberts, Nikolas J., Horswell, Sarah L., Mehellou, Youcef, and Tucker, James H. R.

Subjects
FERROCENE derivatives, ANTINEOPLASTIC agents, NUCLEOSIDE derivatives, HYDROXY acids, CANCER cells, CYCLOPENTANE derivatives, X-ray diffraction, ALKYLATION
Abstract

A new series of chiral ferrocene derivatives containing both a hydroxyalkyl group and a thyminyl group on one cyclopentadienyl ring have been synthesised to probe structure-activity relationships in cancer cell line cytotoxicities. The stereoisomers of enantiomeric pairs of these so-called ferronucleosides have been studied and characterised by a combination of chiral analytical HPLC and single-crystal X-ray diffraction. Biological activity studies revealed that changing the length of the hydroxyalkyl group had marked effects on IC50 values, with compounds having shorter arms that more closely resemble endogenous nucleosides exhibiting lower cytotoxicities. The lipophilicities and electrochemical properties of this compound series have been studied to rationalise these trends and indicate future directions of study. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

89. Synthesis of azetidines and pyrrolidines via iodocyclisation of homoallyl amines and exploration of activity in a zebrafish embryo assay

Author

Feula, Antonio, primary, Dhillon, Sundeep S., additional, Byravan, Rama, additional, Sangha, Mandeep, additional, Ebanks, Ronald, additional, Hama Salih, Mariwan A., additional, Spencer, Neil, additional, Male, Louise, additional, Magyary, Istvan, additional, Deng, Wei-Ping, additional, Müller, Ferenc, additional, and Fossey, John S., additional

Published
2013
Full Text
View/download PDF

93. Tuning the oxidation potential of 2-phenylpyridine-based iridium complexes to improve the performance of bluish and white OLEDs.

Author

Male, Louise, Baranoff, Etienne, Wang, Yafei, Fan, Jiang, Liu, Yu, Zhu, Weiguo, Sun, Ning, Ma, Dongge, and Curchod, Basile F. E.

Abstract

The use of electron-withdrawing substituents on the orthometalated phenyl ring is a common strategy to blue shift the emission of cyclometalated iridium complexes by stabilizing the highest occupied molecular orbital (HOMO), that is, increasing the oxidation potential of the complex. However, for application in blue organic light-emitting diodes (OLEDs), this approach imposes host materials with a deep HOMO, which negatively impacts the injection of charges, and hence the performance of the devices. In this context, we report new iridium complexes with an electron-donating substituent on the cyclometalated ligand to blue shift the emission while keeping a relatively low oxidation potential. As a result, bluish-green OLEDs based on host materials with shallow HOMOs (TCTA = 4,4′,4′′-tri(N-carbazolyl)-triphenylamine) display a higher performance than devices using FIrpic in the same architecture. The improvements are primarily attributed to the lower turn-on voltage (2.8 to 3 V) compared to those of FIrpic-device (3.6 V). White OLED was then prepared with a maximum brightness of 20 226 cd m−2 and current efficiency of 20.4 cd A−2 (at 100 cd m−2). Interestingly, a very small efficiency roll-off of about 1% at 1000 cd m−2 and high color stability were achieved. At a luminance level of 5000 cd m−2 the roll-off efficiency was still below 20%. The introduction of electron-donating substituents on a 2-phenylpyridine scaffold to obtain blue emitters with low oxidation potentials provides an alternative to strategies based on replacing the pyridine with imidazole, carbene, and pyrazole. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

97. Structural and In Vitro Biological Studies of Organotin(IV) Precursors; Selective Inhibitory Activity Against Human Breast Cancer Cells, Positive to Estrogen Receptors

Author

Balas, Vasilis I., primary, Banti, Christina N., additional, Kourkoumelis, Nikolaos, additional, Hadjikakou, Sotiris K., additional, Geromichalos, George D., additional, Sahpazidou, Despina, additional, Male, Louise, additional, Hursthouse, Mike B., additional, Bednarz, Barbara, additional, Kubicki, Maciej, additional, Charalabopoulos, Konstantinos, additional, and Hadjiliadis, Nick, additional

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results