Fluorescent and electrochemical sensing of (poly)phosphate nucleotides by ferrocene functionalised with two (ZnII-TACN-pyrene) complexes

The [Fc[BOND]bis{ZnII(TACN)(Py)}] complex, comprising two ZnII(TACN) ligands (Fc=ferrocene; Py=pyrene; TACN=1,4,7-triazacyclononane) bearing fluorescent pyrene chromophores linked by an electrochemically active ferrocene molecule has been synthesised in high yield through a multistep procedure. In the absence of the polyphosphate guest molecules, very weak excimer emission was observed, indicating that the two pyrene-bearing ZnII(TACN) units are arranged in a trans-like configuration with respect to the ferrocene bridging unit. Binding of a variety of polyphosphate anionic guests (PPi and nucleotides di- and triphosphate) promotes the interaction between pyrene units and results in an enhancement in excimer emission. Investigations of phosphate binding by 31P NMR spectroscopy, fluorescence and electrochemical techniques confirmed a 1:1 stoichiometry for the binding of PPi and nucleotide polyphosphate anions to the bis(ZnII(TACN)) moiety of [Fc[BOND]bis{ZnII(TACN)(Py)}] and indicated that binding induces a trans to cis configuration rearrangement of the bis(ZnII(TACN)) complexes that is responsible for the enhancement of the pyrene excimer emission. Pyrophosphate was concluded to have the strongest affinity to [Fc[BOND]bis{ZnII(TACN)(Py)}] among the anions tested based on a six-fold fluorescence enhancement and 0.1 V negative shift in the potential of the ferrocene/ferrocenium couple. The binding constant for a variety of polyphosphate anions was determined from the change in the intensity of pyrene excimer emission with polyphosphate concentration, measured at 475 nm in CH3CN/Tris-HCl (1:9) buffer solution (10.0 mM, pH 7.4). These measurements confirmed that pyrophosphate binds more strongly (Kb=(4.45±0.41)×106 M−1) than the other nucleotide di- and triphosphates (Kb=1–50×105 M−1) tested.

Electrochemistry of room temperature protic ionic liquids

Eighteen protic ionic liquids containing different combinations of cations and anions, hydrophobicity, viscosity, and conductivity have been synthesized and their physicochemical properties determined. In one series, the diethanolammonium cations were combined with acetate, formate, hydrogen sulfate, chloride, sulfamate, and mesylate anions. In the second series, acetate and formate anions were combined with amine bases, triethylamine, diethylamine, triethanolamine, di-n-propylamine, and di-n-butylamine. The electrochemical characteristics of the eight protic ionic liquids that are liquid at room temperature (RTPILs) have been determined using cyclic, microelectrode, and rotating disk electrode voltammetries. Potential windows of the RTPILs have been compared at glassy carbon, platinum, gold, and boron-doped diamond electrodes and generally found to be the largest in the case of glassy carbon. The voltammetry of IUPAC recommended potential scale reference systems, ferrocene/ferrocenium and cobaltocenium/cobaltocene, have been evaluated and found to be ideal in the case of the less viscous RTPILs but involve adsorption in the highly viscous ones. Other properties such as diffusion coefficients, ionic conductivity, and double layer capacitance also have been measured. The influence of water on the potential windows, viscosity, and diffusion has been studied systematically by deliberate addition of water to the dried ionic liquids. The survey highlights the problems with voltammetric studies in highly viscous room temperature protic ionic liquids and also suggests the way forward with respect to their possible industrial use.

Macrocyclic Zn complexes for DNA detection

Researchers from Monash University have developed an electrocatalytic method based on a charge transport through DNA films, which allows detection of complementary over non-complementary and mismatched DNA sequences in fully hybridized duplexes.

Non-additivity of Faradaic and capacitance terms in ionic liquids

A study was conducted to evaluate the unexpected non-additivity of Faradaic and capacitance currents encountered in the case of ionic liquids. The results highlight that the non-additivity of Faradaic and capacitance currents should be considered in IL electrochemistry when multiple solutes are present.

Intimacy and making : thinking constellations of consciousness and the movements of invention

This paper takes up the three terms - creativity, consciousness and intimacy - and positions them as possible ‘ultimate terms’. Inquiring into the use of these terms to garner approval, status or power within cultural contexts, the paper attempts to unpack them, and simultaneously to seek out any structural similarities in the ways that they operate. The term ‘creativity’ is deconstructed via a Derridean framework, wherein ‘inventiveness’ is posited as a more rigorous alternative in most cases. Consciousness is read closely in relation to its association with notions of awareness and ‘enlightenment’. And ‘intimacy’ is playfully explored as an alternative term for enlightenment, a manoeuvre which brings to the fore some structural assumptions about that which intimacy might comprise. The assumption of intimacy as a spatially-dependent notion is also interrogated. The paper contends that intimacy may involve an unsettling of spatial assumptions proper, and therefore not be simply a function of closeness or distance. It draws on Serres’ notion of the angel as messenger and as analogy for the preposition, indicator of position, but occupant of none. Finally an example from art practice is offered, one that arguably performs the terms intimacy and creativity at once: an epistolary adventure in poetry and photographs, called The Post Project.

Extraction of silver(i) from aqueous solutions in the absence and presence of copper(ii) with a methimazole-based ionic liquid

The ionic liquid (IL) 2-butylthiolonium bis(trifluoromethanesulfonyl)amide, [mimSBu][NTf₂], facilitates the efficient extraction of silver(i) from aqueous media via interaction with both the cation and anion components of the IL. Studies with a conventional aqueous-IL two phase system as well as microextraction of silver(i) by a thick IL film adhered to an electrode monitored in situ by cyclic voltammetry, established that [mimSBu][NTf₂] can extract electroactive silver(i) ions from an aqueous solution. The pH of the aqueous phase decreases upon addition of [mimSBu]⁺, which is attributed to partial release of the hydrogen attached to the N(3) nitrogen atom of the imidazolium ring. The presence of silver(i) further increase the acidity of the aqueous phase as a consequence of coordination with the IL cation component. Voltammetric and ¹H and ¹³C NMR techniques have been used to establish the nature of the silver(i) complexes extracted, and show that the form of interaction with the IL differs from that outlined previously for the extraction of copper(ii). Insights on the competition established when silver(i) is extracted in the presence of copper(ii) are provided. Finally, it is noted that metallic silver can be directly electrodeposited at the electrode surface after extraction of silver(i) into [mimSBu][NTf₂] and that back extraction of silver(i) into aqueous media is achieved by addition of an acidic aqueous solution.

Closer

Contemporary dance has only recently gained the capability of mapping imagery into 3D theatre environments that appear to move towards and away from the audiences. This capability radically expands the metaphoric content possible in dance work. This work was animated by Megan Beckwith, performed and choreographed by Stephanie Hutchison with the sound designed by Jacques Soddell. The performance combines contemporary dance with stereoscopic illusions and video imagery. The work is based on the Walter Benjamin’s Ninth Thesis on the Philosophy of History, 1938. Benjamin describes the angel of history being ‘caught in a storm’ from Paradise and being ‘propelled into the future to which his back is turned’. This performance comments on how we invariably move into the future by taking our past with us.

Allelujah (dance version)

Allelujah Dance Version is a dance piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included. It centers on a female vocal singing Alleluia, with violin, cello, piano, harp, drums and bass.

Electrochemical properties and applications of ionic liquids

This book presents the latest research in electrochemical properties and applications of ionic liquids. While there is no universally agreed upon definition, an ionic liquid may be conveniently described as a compound composed entirely of ions that is a liquid at temperatures less than 100 °C. However, this is an arbitrary definition employed to distinguish ionic liquids from classically well-known molten salts. This book addresses a comprehensive overview of the area, because it is obvious that ionic liquids have the ability to offer many advantages, but also some disadvantages, over traditional molecular solvent (electrolyte) media in the field of electrochemistry.

Allelujah loop 01

Allelujah Loop 01 is a cinematic and New Age piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included or any other religious celebration where Allelujah gives praise. It centers on a female vocal singing Alleluia, with violin, cello, piano, harp and 2 synths and bells at the very end.

Allelujah short 01

Allelujah Short 01is a cinematic and New Age piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included. It centers on a female vocal singing Alleluia, with violin, cello, piano, harp and 2 synths and bells at the very end.

Allelujah short 02

Allelujah Short 02 is a cinematic and New Age piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included. It centers on a female vocal singing Alleluia, with violin, cello, piano, harp and 2 synths and bells at the very end.

Allelujah short 03

Allelujah Short 03 is a cinematic and New Age piece that also fits well with projects of a religious or spiritual theme; Christmas and Easter included. It centers on a female vocal singing Alleluia, with bells end.