RESUMEN
Electrochemical device with components having direct significance to biological life processes is a potent futuristic strategy for the realization of all-round green and sustainable development. We present here synthesis design, structural analysis and ion transport of a novel solid organic electrolyte (G7Li), a compound reminiscent of ion channels, derived from regioisomeric N7-guanine-carboxylate conjugate and Li-ions. G7Li, with it's in-built supply of Li(+)-ions, exhibited remarkably high lithium-ion transference number (= 0.75) and tunable room temperature ionic conductivity spanning three decades (≈10(-7) to 10(-3) Ω(-1) cm(-1)) as a function of moisture content. The ionic conductivity show a distinct reversible transition around 80-100 °C, from a dual Li(+) and H(+) (<100 °C) to a pure Li(+) conductor (>100 °C). Systematic studies reveal a transition from water-assisted Li-ion transport to Li hopping-like mechanism involving guanine-Li coordination. While as-synthesized G7Li has potential in humidity sensors, the anhydrous G7Li is attractive for rechargeable batteries.
Asunto(s)
Electrólitos/química , Guanina/química , Litio/química , Conductividad Eléctrica , Electrólitos/síntesis química , Guanina/análogos & derivados , Guanina/síntesis química , Canales Iónicos/química , Transporte Iónico , Iones/química , Agua/químicaRESUMEN
Three copper-N9-modified guanine complexes are reported with structures ranging from a discrete trinuclear motif to a mixed-valence coordination polymer. These complexes were used as precursors for the deposition and growth of copper oxide thin films on Si(100), at two different annealing temperatures, by using a CVD technique. Subsequent resistivity measurements suggest the formation of conductive thin films, raising the possibility of using nucleobase-metal complexes as versatile thin film precursors.
Asunto(s)
Cobre/química , Guanina/química , Polímeros/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Estructura Molecular , Difracción de Polvo , Espectrofotometría InfrarrojaRESUMEN
The simple strategy of linking guanine to single-walled carbon nanotubes (CNTs) through covalent functionalization permitted generation of the alignment of the nanotubes into lozenges reminiscent of guanine quartets (G-quartets) in the presence of potassium ions as observed by atomic force microscopy.
Asunto(s)
Cristalización/métodos , Guanina/química , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestructura , Dimerización , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
This communication describes mercury(II)-mediated cyclization of N9-propargylguanine under hydrothermal conditions. The structural investigations reported here confirm cyclization and reveal simultaneous formation of a unique organomercury adduct of a tricyclic guanine derivative.
