Four new disubstituted propylenedioxythiophene polymers have been synthesized by Grignard metathesis on the 1−5 g scale. All polymers were found to be soluble in chloroform, methylene chloride, toluene, and tetrahydrofuran and were fully structurally characterized having GPC determined number-average molecular weights ranging from 33000 to 47000 g mol-1. Dilute polymer solutions in toluene exhibited strong red fluorescence with moderate quantum efficiencies from 0.38 to 0.50. Homogeneous thin films were formed by electropolymerization and spray casting polymer solutions onto ITO coated glass slides at thicknesses of ca. 150 nm. The films were electroactive, switching from a dark blue-purple to a transmissive sky blue upon p-doping, often with subsecond switching times, and high electrochromic contrast luminance changes (% ΔY) of 40−70%. These studies revealed that the branched derivatives, [poly(3,3-bis(2-ethylhexyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine)] and [poly(6,8-dibromo-3,3-bis(2-ethylhexyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine)], gave an electrochemical response and associated color change over a much smaller voltage range in comparison to the linear chain substituted derivatives, [poly(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine)] and [poly(3,3-bis(octadecyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine)]. Composite coloration efficiency values were found up to 1365 cm2/C; this was considerably larger than values obtained from previously studied alkylenedioxythiophene based polymers (∼375 cm2/C).

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This work demonstrates a simple process to form insoluble poly(3,4-propylenedioxythiophene) (Poly[ProDOT]) films by defunctionalization of a soluble form, which is useful in the fabrication of multilayer polymer devices. Three new ester disubstituted Poly[ProDOTs], soluble in common organic solvents, including chloroform, methylene chloride, toluene, tetrahydrofuran, and ethyl acetate, have been synthesized by oxidative polymerization using iron(III) chloride. These Poly[ProDOT-diesters] have the expected repeat unit stuctures along with GPC determined number-average molecular weights ranging from 9000 to 12 000 g mol-1. Dilute polymer solutions in toluene exhibited red fluorescence with quantum efficiencies from 0.24 to 0.32. Homogeneous thin films were formed by spray casting polymer solutions onto ITO coated glass slides and compared to films prepared by electropolymerization. These Poly[ProDOT-diesters] are electroactive, switching from a dark blue-purple to a transmissive sky blue when potentials are applied between −0.9 and +0.3 V vs Fc/Fc.+ A thin film saponification method was developed and rendered the spray-cast films insoluble by submersion into 0.1 M KOH in hot methanol for 1 h to remove the solubilizing ester group. In the case of a bis(heptanoate) Poly[ProDOT-diester] (1), spectroelectrochemistry showed minimal change in its electronic spectra after methanolysis and the resulting alcohol-substituted polymer (Poly[ProDOT-diol] (4)) could be repeatably switched between neutral and oxidized states in subsecond times. In contrast, when a more highly functionalized Poly[ProDOT-tetraester] (3) was used, a small change in the electronic spectrum which is associated with a distinct color change from burgundy to blue was observed upon methanolysis to Poly[ProDOT-tetraol] (6). The insoluble alcohol-substituted polymer films were found to be efficient hole transport layers in polymer light-emitting diodes.

We study two-photon absorption (2PA) spectra in a broad class of organic dye molecules, such as substituted diphenylaminostilbenes, push−pull porphyrins, and carbazol-substituted stilbenes. We show, for the first time, that the 2PA cross section in the lowest-energy dipole-allowed transition may be predicted with better than 50% absolute accuracy based solely on the molecular parameters obtained from linear spectroscopic measurements.

Three color states and a large luminance change at intermediate potentials are the key features of a new alkylenedioxypolythiophene, in which two polymeric strands are linked by a spiro(bis‐dioxacycloheptene) unit (see Figure). The seven‐membered rings are quite flexible and allow coplanarity of both strands. The polymer is both cathodically and anodically coloring, showing a dark red neutral state and a dark blue oxidized state.

The origin and evolutionary relationship of viruses is poorly understood. This makes archaeal virus-host systems of particular interest because the hosts generally root near the base of phylogenetic trees, while some of the viruses have clear structural similarities to those that infect prokaryotic and eukaryotic cells. Despite the advantageous position for use in evolutionary studies, little is known about archaeal viruses or how they interact with their hosts, compared to viruses of bacteria and eukaryotes. In addition, many archaeal viruses have been isolated from extreme environments and present a unique opportunity for elucidating factors that are important for existence at the extremes. In this article we focus on virus-host interactions using a proteomics approach to study Sulfolobus Turreted Icosahedral Virus (STIV) infection of Sulfolobus solfataricus P2. Using cultures grown from the ATCC cell stock, a single cycle of STIV infection was sampled six times over a 72 h period. More than 700 proteins were identified throughout the course of the experiments. Seventy one host proteins were found to change their concentration by nearly twofold (p < 0.05) with 40 becoming more abundant and 31 less abundant. The modulated proteins represent 30 different cell pathways and 14 clusters of orthologous groups. 2D gel analysis showed that changes in post-translational modifications were a common feature of the affected proteins. The results from these studies showed that the prokaryotic antiviral adaptive immune system CRISPR-associated proteins (CAS proteins) were regulated in response to the virus infection. It was found that regulated proteins come from mRNAs with a shorter than average half-life. In addition, activity-based protein profiling (ABPP) profiling on 2D-gels showed caspase, hydrolase, and tyrosine phosphatase enzyme activity labeling at the protein isoform level. Together, this data provides a more detailed global view of archaeal cellular responses to viral infection, demonstrates the power of quantitative two-dimensional differential gel electrophoresis and ABPP using 2D gel compatible fluorescent dyes.

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The conversion of S-nitrosothiols to thiosulphonates by reaction with the sodium salt of benzenesulfinic acid (PhSO2Na) has been examined in detail with the exemplary substrates S-nitrosoglutathione (GSNO) and S-nitrosylated bovine serum albumin (SNO-BSA). The reaction stoichiometry (2:1, PhSO2Na:RSNO) and the rate law (first order in both PhSO2Na and RSNO) have been determined under mild acidic conditions (pH 4.0). The products have been identified as the corresponding thiosulphonates (GSSO2Ph and BSA-SSO2Ph) along with PhSO2NHOH obtained in a 1:1 ratio. GSH, GSSG, and BSA were unreactive to PhSO2Na.