Synthesis, spectroscopy and photophysical properties of ruthenium triazole complexes and their application as dye-molecules in regenerative solar cells

The complexes [Ru(dcb)2(L)] (L = 3-(2-phenol)-5-(pyridin-2-yl)-1,2,4-triazole (2-ppt), 3-(4-phenol)-5-(pyridin-2-yl)-1,2,4-triazole (4-ppt), 3,5-bis(pyrazin-2-yl)-1,2,4-triazole (bpzt), 3-(2-phenol)-5-(pyrazin-2-yl)-1,2,4-triazole (2-ppzt) and dcb = 4,4’-(CO2H)2-2,2’-bipyridine) have been synthesized, spectroscopically characterized and anchored to nanocrystalline TiO2 electrodes for the conversion of light into electricity in regenerative solar cells. The different efficiencies observed have been rationalized on the basis of an analytical expression relating the incident photon-to-current-conversion efficiency (IPCE) to the kinetic parameters of the relevant electron transfer processes involved in the solar cell

Design of OsII-based Sensitizers for Dye-Sensitized Solar Cells:Influence of Heterocyclic Ancillaries

A series of OsII sensitizers (TFOS-x, in which x=1, 2, or 3) with a single 4,4′-dicarboxy-2,2′-dipyridine (H2dcbpy) anchor and two chelating 2-pyridyl (or 2-pyrimidyl) triazolate ancillaries was successfully prepared. Single-crystal X-ray structural analysis showed that the core geometry of the OsII-based sensitizers consisted of one H2dcbpy unit and two eclipsed cis-triazolate fragments; this was notably different from the RuII-based counterparts, in which the azolate (both pyrazolate and triazolate) fragments are located at the mutual trans-positions. The basic properties were extensively probed by using spectroscopic and electrochemical methods as well as time-dependent density functional theory (TD-DFT) calculations. Fabrication of dye-sensitized solar cells (DSCs) was then attempted by using the I−/I3−-based electrolyte solution. One such DSC device, which utilized TFOS-2 as the sensitizer, showed promising performance characteristics with a short-circuit current density (JSC) of 15.7 mA cm−2, an open-circuit voltage of 610 mV, a fill factor of 0.63, and a power conversion efficiency of 6.08 % under AM 1.5G simulated one-sun irradiation. Importantly, adequate incident photon-to-current conversion efficiency performances were observed for all TFOS derivatives over the wide spectral region of 450 to 950 nm, showing a panchromatic light harvesting capability that extended into the near-infrared regime. Our results underlined a feasible strategy for maximizing JSC and increasing the efficiency of DSCs

Remote interfacial electron transfer processes on nanocrystalline TiO

The kinetic study of interfacial electron transfer in sensitized nanocrystalline semiconductor is essential to the design of molecular devices performing specific light induced functions in a microheterogeneous environment. A series of molecular assemblies performing direct and remote charge injection to the semiconductor have been discussed in the context of artificial photosynthesis. A particular attention in this article has been paid to the factors that control the interfacial electron transfer processes in nanocrystalline TiO2 films sensitized with mononuclear and polynuclear transition metal complexes

PROCESS FOR THE PREPARATION OF CARBOXYLATE AND PHOSPHONATE RUTHENIUM POLYPYRIDINE DYES AND A PROCESS FOR THE PREPARATION OF REACTION INTERMEDIATES USED IN SUCH PROCESS

The present invention relates to processes indicated by method A and B for the preparation of carboxylate and phosphonate Ruthenium Polypyridine Dyes and for the preparation of reaction intermediates used in such process

Idiopathic Hypereosinophilic Syndrome with Multiple Organ Involvement

Idiopathic hypereosinophilic syndrome is a rare disease which is diagnosed after excluding other conditions. The syndrome is characterized by multiple organ involvement including the heart, nervous system, lungs, and gastrointestinal tract. The disease is suspected if there is peripheral blood eosinophilia and no clear etiology. The main treatment is corticosteroids. Patients who do not respond to corticosteroids can be treated with imatinib, immunomodulatory agents, myelosuppressive therapy, or mepolizumab. Alemtuzumab can be considered in severe cases that are unresponsive to other therapies. In this paper, we describe a case of idiopathic hypereosinophilic syndrome with mainly cardiac system involvement and left ventricular thrombus formation which was complicated by cerebral thromboemboli while on warfarin with international normalized ratio in the therapeutic range. Our patient responded well to steroids appreciated by improvement in clinical symptoms and decrease in eosinophil count. </jats:p

Efficiency enhancement of the electrocatalytic reduction of CO2:fac-[Re(v-bpy)(CO)3Cl] electropolymerized onto mesoporous TiO2 electrodes

As the greenhouse effect increases, the development of systems able to convert with high efficiency CO2 to energetically rich molecules owns a crucial weight in the technological and environmental domain. As catalyst, rhenium complexes, of the type fac-[Re(L)(CO)(3)Cl] (i.e. L = 2,2'-bipyridyl or 4,4'-bipyridyl), have attracted a large interest demonstrating promising catalytic properties. fac-[Re(v-bpy)(CO)(3)Cl]-based polymer deposited onto a solid support has been already investigated as heterogeneous catalyst in the reduction of CO2. Here, we deposited by electrochemical polymerization fac-[Re(v-bpy)(CO)(3)Cl] onto a nanocrystalline TiO2 film on glass and we investigated by cyclic voltammetry the properties of such heterogeneous catalyst in the electrochemical reduction of CO2. We demonstrated that the nanoporous nature of the substrate allows to increase the two-dimensional number of redox sites per surface area and hence to get a significant enhancement of the catalytic yield

Efficiency enhancement of the electrocatalytic reduction of CO2: fac-[Re(v-bpy)(CO)3Cl] electropolymerized onto mesoporous TiO2 electrodes.

As the greenhouse effect increases, the development of systems able to convert with high efficiency CO2 to energetically rich molecules owns a crucial weight in the technological and environmental domain. As catalyst, rhenium complexes, of the type fac-[Re(L)(CO)(3)Cl] (i.e. L = 2,2'-bipyridyl or 4,4'-bipyridyl), have attracted a large interest demonstrating promising catalytic properties. fac-[Re(v-bpy)(CO)(3)Cl]-based polymer deposited onto a solid support has been already investigated as heterogeneous catalyst in the reduction of CO2. Here, we deposited by electrochemical polymerization fac-[Re(v-bpy)(CO)(3)Cl] onto a nanocrystalline TiO2 film on glass and we investigated by cyclic voltammetry the properties of such heterogeneous catalyst in the electrochemical reduction of CO2. We demonstrated that the nanoporous nature of the substrate allows to increase the two-dimensional number of redox sites per surface area and hence to get a significant enhancement of the catalytic yield