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The design, synthesis, and characterization of solution-processable polymers for organic light emitting diode (OLED) applications are presented. Theoretical calculations were employed to identify a carbazole-pyrimidine based building block as an optimized host material for the emissive layer of an idealized OLED stack. Efficient, free radical homopolymerization and copolymerization with a novel methacrylate-based heteroleptic iridium(III) complex leads to a library of nonconjugated polymers with pendant semiconductors. Optoelectronic characterization reveals impressive photoluminescence quantum yield (PLQY) values exceeding 80% and single-layer OLEDs show optimal performance for copolymers containing 6 mol % of iridium comonomer dopant.

A novel strategy for the synthesis and characterization of branched polymer brushes by sequential light-mediated controlled radical polymerizations is described. Initially, linear brushes are prepared by surface-initiated copolymerization of methyl methacrylate and 2-hydroxyethyl methacrylate (HEMA). In a subsequent step, the HEMA side chains are functionalized with initiating groups for secondary graft polymerization, leading to hierarchical, branched architectures. The increased steric bulk due to the polymer side chains results in a dramatic increase in film thickness when compared to the starting linear brushes. This strategy also allows chemical gradient and complex three-dimensional structures to be obtained by employing grayscale photomasks in combination with controlled radical polymerization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2276–2284

© The Royal Society of Chemistry 2016. Triazine-based unimolecular initiators are shown to mediate the controlled radical polymerization of several monomer classes, yielding polymers with low dispersities, targeted molecular weights, and active chain ends. We report the modular synthesis of structurally and electronically diverse triazine-based unimolecular initiators and demonstrate their ability to efficiently control the radical polymerization of modified styrene monomers. Copolymerizations of styrene with butyl acrylate or methyl methacrylate were conducted to highlight the monomer family tolerance of this system. Notably, in the case of methyl methacrylate and styrene, up to 90 mol% methyl methacrylate comonomer loadings could be achieved while maintaining a controlled polymerization, allowing the synthesis of a range of block copolymers. This class of triazine-based mediators has the potential to complement current methods of controlled radical polymerization and marks an important milestone in ongoing efforts to develop initiators and mediators with high monomer tolerance that are both metal and sulfur-free.

A light-mediated methodology to grow patterned, emissive polymer brushes with micron feature resolution is reported and applied to organic light emitting diode (OLED) displays. Light is used for both initiator functionalization of indium tin oxide and subsequent atom transfer radical polymerization of methacrylate-based fluorescent and phosphorescent iridium monomers. The iridium centers play key roles in photocatalyzing and mediating polymer growth while also emitting light in the final OLED structure. The scope of the presented procedure enables the synthesis of a library of polymers with emissive colors spanning the visible spectrum where the dopant incorporation, position of brush growth, and brush thickness are readily controlled. The chain-ends of the polymer brushes remain intact, affording subsequent chain extension and formation of well-defined diblock architectures. This high level of structure and function control allows for the facile preparation of random ternary copolymers and red–green–blue arrays to yield white emission., Emissive polymer brushes are grafted from conductive substrates via photocatalysis for organic light emitting diode displays. Color tunability, micron pixel features, thickness control, and diblocks are demonstrated.

Overcoming the challenge of metal contamination in traditional ATRP systems, a metal-free ATRP process, mediated by light and catalyzed by an organic-based photoredox catalyst, is reported. Polymerization of vinyl monomers are efficiently activated and deactivated with light leading to excellent control over the molecular weight, polydispersity, and chain ends of the resulting polymers. Significantly, block copolymer formation was facile and could be combined with other controlled radical processes leading to structural and synthetic versatility. We believe that these new organic-based photoredox catalysts will enable new applications for controlled radical polymerizations and also be of further value in both small molecule and polymer chemistry.

This review summarizes the field of metal-catalyzed ring-expanding carbonylation of epoxides. Specifically, epoxide carbonylation to -, -, and -lactones is reviewed, in addition to epoxide carbonylation to succinic anhydrides, 1,3-oxazinane-2,4-diones and 1,3-oxathiolan-2-ones. For each reaction, the mechanism of catalysis and control of stereochemistry are discussed and the scope and limitations of the catalysts are considered. Experimental conditions and procedures are also presented. In addition, non-carbonylative routes preparing similar products are compared. Keywords: Carbonylation; carbon-carbon bond formation; carbon monoxide; catalysis; epoxide; lactone; ring-expansion; succinic anhydride

[reaction: see text] A readily prepared bimetallic catalyst is capable of effecting epoxide carbonylation to produce beta-lactones at substantially lower CO pressures than previously reported catalyst systems. A functionally diverse array of beta-lactones is produced in excellent yields at CO pressures as low as 1 atm. This procedure allows for epoxide carbonylation on a multigram scale without the requirement of specialized, high-pressure equipment.

The controlled radical polymerization of a variety of acrylate monomers is reported using an Ir-catalyzed visible light mediated process leading to well-defined homo-, random, and block copolymers. The polymerizations could be efficiently activated and deactivated using light while maintaining a linear increase in molecular weight with conversion and first order kinetics. The robust nature of the fac-[Ir(ppy)3] catalyst allows carboxylic acids to be directly introduced at the chain ends through functional initiators or along the backbone of random copolymers (controlled process up to 50 mol % acrylic acid incorporation). In contrast to traditional ATRP procedures, low polydispersity block copolymers, poly(acrylate)-b-(acrylate), poly(methacrylate)-b-(acrylate), and poly(acrylate)-b-(methacrylate), could be prepared with no monomer sequence requirements. These results illustrate the increasing generality and utility of light mediated Ir-catalyzed polymerization as a platform for polymer synthesis. © 2014 American Chemical Society.

Substituted 3-hydroxy-delta-lactones (3HLs) are valuable intermediates in the synthesis of pharmaceuticals and other biologically active natural products. Herein we report the first example of the catalytic carbonylation of substituted homoglycidols to 3HLs using HCo(CO)4. Upon optimization of the catalyst and reaction conditions, a functionally diverse set of 3HLs was prepared. Mechanistic insight was gained by observation of the carbonylation reaction using in situ IR spectroscopy, and we propose a mechanism that is consistent with previously studied epoxide carbonylation systems.

A modular and general method based on a photomediated ATRA reaction for the spatially controlled functionalization of surfaces with visible light is reported. The ability to control reactivity with light intensity combined with the orthogonality of ATRA chemistry allows well-defined chemically differentiated monolayers and complex nonlinear chemical concentration gradients to be easily prepared. Use of light to mediate these reactions permits spatial regulation and the generation of unique, multifunctional chemical gradients. © 2013 American Chemical Society.

Directed self-assembly (DSA) of block copolymers (BCPs) is a promising technology for advanced patterning at future technology nodes, but significant hurdles remain for commercial implementation. The most widely studied material for DSA is poly(styrene-block-methyl methacrylate) (PS-PMMA), but the relatively weak segregation strength of PSPMMA results in some limitations. This paper reports on these limitations for PS-PMMA and highlights a path to success through use of more strongly segregated “high-χ” block copolymers. In general, stronger segregation is predicted to lower defectivity at equilibrium, but unfortunately, kinetics of self assembly also becomes much slower as segregation strength increases. Recognizing diffusion is much faster for cylinder morphologies than lamellar ones, we have investigated new cylinder-forming BCPs that enable defect elimination with thermal annealing processes. In addition, a formulation strategy is presented that further improves the kinetics of the assembly process, enabling tremendous improvements in defectivity over simple BCP systems. Excitingly, successful chemoepitaxy DSA with a high-χ lamellar BCP is also demonstrated using a thermal annealing process and no top coat. These technologies hold promise to enable DSA with thermal annealing processing across pitches from 40 - 16 nm.

Directed self-assembly (DSA) of block copolymers (BCPs) is a promising technology for advanced patterning at future technology nodes, but significant hurdles remain for commercial implementation. The most widely studied material for DSA is poly(styrene-block-methyl methacrylate) (PS-PMMA), but this material has a relatively weak segregation strength that has limited its utility to patterns above 24 nm pitch. This paper reports on some of Dow's efforts to develop new materials capable of extending DSA to smaller pitch by development of new BCP copolymer materials with stronger segregation strength. Some preliminary efforts are reported on new substrate treatments that stabilize perpendicular orientations in a high-c block copolymer that also incorporate an etch-resistant block to facilitate patterning at small dimensions. In addition, development of new block copolymer materials that have a c-parameter that is large enough to drive defect reduction and but not so high that it precludes thermal annealing are also presented. DSA of these new materials is demonstrated using thermal annealing processes at pitch ranging from 40 to 16 nm, and etch capability is also demonstrated on a material with 18 nm pitch. These technologies hold promise for the extension of DSA to sub 24 nm pitch.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

4-Substituted oxazolines, which are readily synthesized from naturally occurring α-amino acids, are converted efficiently and stereospecifically to β-amidoaldehydes in the presence of synthesis gas and catalytic dicobalt octacarbonyl.

1,2-Epoxy-3-phenoxypropane [N,N'-Bis(3,5-di-tert-butylsalicylidene)-1,2-phenylenediamino-chromium-di-tetrahydrofuran]tetracarbonylcobaltate(1) Carbon monoxide Keywords: low pressure; carbonylation; epoxides. beta-lactones; functionally diverse beta-lactones; pressure reactors; waste disposal; safety

The ring-opening polymerization of a mixture of enantiomerically pure but different monomers using an yttrium complex as initiator proceeds readily at room temperature to give the corresponding highly alternating polyester.

Efficient and mild reaction conditions were developed for the catalytic carbonylation of fluorinated epoxides to their corresponding β-lactones. Six new lactones with fluorinated side chains were prepared in high isolated yields. These lactones were polymerized to form a series of new poly(β-hydroxyalkanoate)s with fluorinated side chains, and their properties were examined with respect to their hydrocarbon analogs. Finally, copolymerizations were performed with fluorinated lactones and β-butyrolactone, which resulted in tapered copolymers rather than the expected random copolymers.

Substituted 3-hydroxy-δ-lactones (3HLs) are valuable intermediates in the synthesis of pharmaceuticals and other biologically active natural products. Herein we report the first example of the catalytic carbonylation of substituted homoglycidols to 3HLs using HCo(CO)4. Upon optimization of the catalyst and reaction conditions, a functionally diverse set of 3HLs was prepared. Mechanistic insight was gained by observation of the carbonylation reaction using in situ IR spectroscopy, and we propose a mechanism that is consistent with previously studied epoxide carbonylation systems.

Publisher Summary Clinical enzymology has made great advances since the introduction of serum alkaline phosphatase as a diagnostic aid. Advancement in bioengineering and computer technology linked enzymology, immunology, and molecular genetics to produce new clinical diagnostic procedures. Qualitative and quantitative nonradioisotopic immunodiagnostics with enzyme-linked monoclonal antibodies enhances the specificity and sensitivity of assays for metabolites, hormones, and infectious agents. Immunocytochemistry has advanced the specificity and sensitivity of light and electron microscopic histology and cytology. Endonucleases combined with DNA probes enable the diagnostician to detect the fingerprints of prepatent genetic defects and infectious agents before or without the aid of endogenous antibody development. Although enzymes appear to have only a passive part in these forms of biotechnology, understanding their fundamental action is essential to clinical diagnostics and basic research. This chapter is intended to be an introduction to enzymes as primary clinical diagnostic aids and their secondary role in other diagnostic techniques.

Canine serum was used to compare seven chemistry analytes on two tabletop clinical dry chemistry analyzers, Boehringer's Reflotron and Kodak's Ektachem. Results were compared to those obtained on a wet chemistry reference analyzer, Roche Diagnostic's Cobas Mira. Analytes measured were urea nitrogen (BUN), creatinine, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and bilirubin. Nine to 12 canine sera with values in the low, normal, and high range were evaluated. The correlations were acceptable for all comparisons with correlation coefficients greater than 0.98 for all analytes. Regression analysis resulted in significant differences for both tabletop analyzers when compared to the reference analyzer for cholesterol and bilirubin, and for glucose and AST on the Kodak Ektachem. Differences appeared to result from proportional systematic error occurring at high analyte concentrations.

Large granular lymphocytes (LGL) occur as a leukemic or aleukemic neoplasia in humans,(1) rats,(2) cats,(3,4) dogs,(5) and horses.(6) The single case of equine LGL previously reported was aleukemic.(5) In contrast to this previous report of aleukemic equine LGL neoplasia, the leukemia in the case presented here established the antemortem diagnosis of LGL.

4-Substituted oxazolines, which are readily synthesized from naturally occurring alpha-amino acids, are converted efficiently and stereospecifically to beta-amidoaldehydes in the presence of synthesis gas and catalytic dicobalt octacarbonyl.

Spontaneous diabetes mellitus has been characterized in a line of nonobese purebred keeshond dogs as an insulin-requiring hereditary disorder with onset at between 2 and 6 mo of age. Diabetic dogs developed cataracts, became ketotic, hyperglycemie, hypercho-lesterolemic, lipemic, and hypoinsulinemic. Basal glucagon, cortisol, and T4 serum concentrations and responses to ACTH, TSH, and arginine were normal. Light microscopic studies of the pancreas by immunocytochemical procedures revealed the absence of islet B cells, the presence of A cells, and solitary B cells. Diabetic dogs had poor fecundity, and a single puberal diabetic male had poor semen quality and was unable to sire pups. Parents of diabetics and nondiabetic siblings were normal. This spontaneous form of diabetes mellitus, with similar lesions to the insulin-dependent diabetes of people, will be a valuable aid to comparative biomedicai research of diabetes mellitus.

Summary Serum enzyme activities were determined in several groups of domestic and wild horses which had been restrained by physical or chemical methods. The values obtained in general did not differ from normal horse values nor between males and females within groups. There were however, many differences between groups and those were attributed in part to the type and duration of capture/captivity experience.

Diabetes mellitus can be produced readily in dogs by any of several chemical or surgical methods, and in recent years genetically diabetic dogs have also become available for study. These models are suitable for investigating a wide variety of questions relevant to human diabetes mellitus. Especially noteworthy is the occurrence in diabetic dogs of a number of ocular and other complications typical of human diabetes mellitus. Procedures by which canine models of diabetes may be established or maintained have been outlined in this report.

Publisher Summary This chapter discusses clinical enzymology. An enzyme in serum, to be valuable as a clinical diagnostic aid, must be readily assayable; its assay must be economically feasible and reasonably reflect pathological change in a specific organ or group of organs. An example of assay ability is the case of the three liver-specific enzymes, anginas (ARG), sorbitol dehydrogenase (SDH), and alanine aminotransferase (GPT). ARG and SDH are liver-specific enzymes in many animals and are excellent markers of hepatocellular damage. GPT is also liver specific in many species but is used in favor of the former two enzymes because the assay for GPT is simpler than that for ARG and SDH, and a large body of clinical background data for GPT is available. Cells need not be necrotic to release their enzymes into plasma. Anoxia causes the cell membrane to lose its integrity and soluble enzyme from the cytosol leaks into plasma. This loss of integrity is often first observed microscopically as a swelling of the cell. An example of enzyme leak is in hepatic congestion, where the GPT activity in serum increases in the absence of frank hepatocytic necrosis. When a serum enzyme lacks sufficient specificity for an organ, a second enzyme may be combined with the first to increase its diagnostic value. Serum alkaline phosphatase activity increases in bone and liver disorders, and, to assist in identifying the source of the increase, GPT or γ-glutamyltransferase may be assayed as part of a hepatic profile.