19,172 research outputs found
Ultra-sensitive lithium niobate thermometer based on a dual-resonant whispering-gallery-mode cavity
No full textAbstract not availableWenle Weng, Philip S. Light and Andre N. Luite
Solvent-induced supramolecular isomerism in Pt(S=C(NH2)(2))(4) (2+) croconate salts
No full textThe role of solvent (and other species) in the formation of networks from tetrakis(thiourea) platinum(II) cations and croconate anions is examined, with crystallisations from DMSO giving rise to a structure containing solvent filled channels
Anion-anion one-dimensional chain formation within cationic channels in tetrabutylammonium dihydrogenphosphate dichloromethane solvate
No full textThe title compound, C16H36N+H2PO4-.1.33CH(2)Cl(2), exists as infinite one-dimensional dihydrogen phosphate chains within cationic tetrabutylammonium channels
Anion binding vs. deprotonation in colorimetric pyrrolylamidothiourea based anion sensors
No full textA pyrrolylamidothiourea deprotonates in the presence of one equivalent of not only fluoride, but also acetate, benzoate or dihydrogen phosphate in DMSO solution with structural studies using synchrotron radiation confirming thiourea deprotonation in the solid state
Pyrrolylamidourea based anion receptors
No full textThe anion binding behaviour of a number of pyrrolylamidourea and thiourea compounds have been studied in DMSO solution. Mono-amidothioureapyrrole compounds were found to be deprotonated by basic anions such as fluoride, acetate, benzoate or dihydrogenphosphate with the structure of the deprotonated species elucidated by X-ray crystallography. 2,5-Bis-amidoureapyrroles were synthesized and found to be effective anion receptors for a range of putative anionic guests
'Twisted' isophthalamide analogues
No full textSteric interactions in 1,3-dicarboxamidoanthraquinones have been employed to 'twist' isophthalamide-like anion binding sites; the crystal structure of the fluoride complex of a bis-3,5-dichlorophenylamide derivative shows the receptor acting as a 'hydrogen-bonding corner' in a '2 + 2' fluoride containing molecular box
Light-shift spectroscopy of optically trapped atomic ensembles
No full textWe develop a method for extracting the physical parameters of interest for a conventional dipole-trapped cold atomic ensemble. This technique uses the spatially dependent ac-Stark shift of the trap itself to project the atomic distribution onto a light-shift broadened transmission spectrum. We develop a model that connects the atomic distribution with the expected transmission spectrum. We then demonstrate the utility of the technique by deriving the temperature, trap depth, lifetime, and trapped atom number from data that was taken in a single shot experimental measurement.Ashby P Hilton, Andre N Luiten and Philip S Ligh
Further insight into the coordination of 2,5-dicarbothioamidopyrroles: the case of Cu and Co complexes
No full textThe coordination chemistry of 2,5-dicarbothioamidopyrrole ligands, namely N2,N5-dibutyl-3,4-diphenyl-1H-pyrrole-2,5-bis(carbothioamide) and N2,N5,3,4-tetraphenyl-1H-pyrrole-2,5-bis(carbothioamide), has been investigated with Cu(II) metal centres by means of X-ray crystallography. This resulted in the formation of the expected planar S,N,S? coordinated complex for the former ligand and unexpected ring-closure reactions, with formation of benzothiazole sidearms, for the latter. Both Cu(II) and Cu(I), used in large excess, were found to favour the ring-closure reaction, although the structural characterisation of the resulting complexes contained only Cu(II) cations, with varying coordination geometries ranging from square planar and square-based pyramidal to tetrahedral. By repeating the reaction using a slight excess of Cu(II) (2 : 1) two more different structures were obtained where the metal was coordinated to the original ligand, N2,N5,3,4-tetraphenyl-1H-pyrrole-2,5-bis(carbothioamide), or to the mixed ligand where only one of the thioamide substituents had converted to a benzothiazole. The essential role of Cu for the ring closure reaction was also established by comparing its complex with structural features of the analogous Co(II) complex, the latter revealing no ring closure to give benzothiazole substituents and co-crystallisation of a mixed Co(II)/Co(III) complex. Finally, the structure and photophysical properties of the corresponding 3,4-diphenyl-2,5-bis(benzothiozol-5-yl)-pyrrole ligand, obtained via treatment of the thioamide with K3[Fe(CN)6], were also investigated revealing a blue-centered emissio
Divalent ytterbium complexes with crown and heterocrown ethers
No full textSeveral unusual complexes of ytterbium(II) stabilised by coordination to mixed O4X2-donor macrocyclic ligands (X = O, NH, S or Se) are described. Distorted 8-coordination is evident from the crystal structure of the neutral [YbI2([18]aneO4Se2)], forming the first reported example of Yb(II)-selenoether coordination
CALDER: Cryogenic light detectors for background-free searches
No full textCALDER is a R&D project for the development of cryogenic light detectors with an active surface of 5x5cm2 and an energy resolution of 20 eV RMS for visible and UV photons. These devices can enhance the sensitivity of next generation large mass bolometric detectors for rare event searches, providing an active background rejection method based on particle discrimination. A CALDER detector is composed by a large area Si absorber substrate with superconducting kinetic inductance detectors (KIDs) deposited on it. The substrate converts the incoming light into athermal phonons, that are then sensed by the KIDs. KID technology combine fabrication simplicity with natural attitude to frequency-domain multiplexing, making it an ideal candidate for a large scale bolometric experiments. We will give an overview of the CALDER project and show the performances obtained with prototype detectors both in terms of energy resolution and efficiency
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