Discovery and frequency measurement of short-wavelength far-infrared laser emissions from optically pumped <Superscript>13</Superscript>CD<Subscript>3</Subscript>OH and CHD<Subscript>2</Subscript>OH

A three-laser heterodyne system was used to measure the frequencies of twelve previously observed far-infrared laser emissions from the partially deuterated methanol isotopologues ¹³CD₃OH and CHD₂OH. Two laser emissions, a 53.773 μm line from ¹³CD₃OH and a 74.939 μm line from CHD₂OH, have also been discovered and frequency measured. The CO₂ pump laser offset frequency was measured with respect to its center frequency for twenty-four FIR laser emissions from CH₃OH, ¹³CD₃OH and CHD₂OH. PACS 07.57.Hm; 42.55.Lt; 42.62.Eh     

A sensitive solid-phase fluoroimmunoassay for detection of opiates in urine

An automated flow fluorometer designed for kinetic binding analysis was adapted to develop a solid-phase competitive fluoroimmunoassay for urinalysis of opiates. The solid phase consisted of polymer beads coated with commercial monoclonal antibodies (MAbs) raised against morphine. Fluorescein-conjugated morphine (FL-MOR) was used as the fluorescein-labeled hapten. The dissociation equilibrium constant (K _D ) for the binding of FL-MOR to the anti-MOR MAb was 0.23 nM. The binding of FL-MOR to the anti-MOR MAb reached steady state within minutes and was displaced effectively by morphine and other opiates. Morphine-3-glucuronide (M3G), the major urinary metabolite of heroin and morphine, competed effectively with FL-MOR in a concentration-dependent manner for binding to the antimorphine MAb and was therefore used to construct the calibration curve. The sensitivity of the assay was 0.2 ng/mL for M3G. The assay was effective at concentrations of M3G from 0.2 to 50 ng/mL, with an IC₅₀ of 2 ng/mL. Other opiates and heroin metabolites that showed >50% crossreactivity when present at 1 μg/mL included codeine, morphine-6-glucuronide, and oxycodone. Methadone showed very low crossreactivity (<5%), which is a benefit for testing in patients being treated for opiate addictions. The high sensitivity of the assay and the relatively high cutoff value for positive opiate tests allows very small sample volumes (e.g., in saliva or sweat) to be analyzed. A double-blind comparison using 205 clinical urine samples showed good agreement between this single-step competitive assay and a commercially performed enzyme multiplied immunoassay technique for the detection of opiates and benzoylecgonine (a metabolite of cocaine).     

Synthesis and characterization of poly(arylene ether imidazole)s

Poly(arylene ether imidazole)s were prepared by the aromatic nucleophilic displacement reaction of a bisphenol imidazole with activated aromatic dihalides. The polymers had glass transition temperatures ranging from 230 to 318°C and number-average molecular weights as high as 82,000 g/mol. Thermogravimetric analysis showed a 5% weight loss occurring ～ 400°C in air and ～ 500°C in nitrogen. Typical neat resin mechanical properties obtained at room temperature included tensile strength and tensile modulus of 14.2 and 407 ksi and fracture energy (G_lc) of 23 in. lb/in.² Titanium-to-titanium tensile shear strengths measured at 23 and 200°C were 4800 and 3000 psi, respectively. In addition, preliminary data were obtained on carbon fiber laminates. The chemistry, physical, and mechanical properties of these polymers are discussed.     

Poly(enamine-ketones) from aromatic diacetylenic diketones and aromatic diamines

Novel poly(enamine-ketones) were prepared with inherent viscosities as high as 1.99 dL/g using the Michael-type addition of various diamines to 1,1′-(1,3 or 1,4-phenylene)bis(3-phenyl-2-propyn-1-one) in m-cresol at 60–130°C. Tough, clear, amber films with tensile strengths of 12, 400 psi and tensile moduli of 397, 000 psi were cast from solutions of the polymers in chloroform. The polymers exhibited T_gs as high as 235°C and weight losses of 14% after aging at 232°C in circulating air for 60 h. The synthesis and characterization of several poly(enamine-ketones) are discussed.     

Polypyrazoles from aromatic dipropynones and aromatic dihydrazines

Two types of polypyrazoles, unsubstituted and phenylated, were prepared by a novel synthetic route involving the cyclopolycondensation of aromatic dihydrazines and aromatic dipropynones. The polymers had inherent viscosities as high as 1.05 dL/g and were soluble in N, N-dimethylacetamide, chloroform (phenylated polypyrazoles only), and sulfuric acid. The polymers exhibited glass transition temperatures ranging from 202 to 266°C and polymer decomposition temperatures (10% weight loss) as measured by thermogravimetric analysis of 400–500°C in air and 465–512°C in nitrogen. The synthesis and characterization of several polypyrazoles are discussed.     

Random Copolymers of 1,5-Dioxepan-2-one

ABSTRACT

Copolymers of 1,5-dioxepan-2-one (DXO) and e-caprolactone (?-CL), δ-valerolactone (δ-VL) or L-lactide (LLA) have been synthesized and characterized. High molecular weight copolymers were obtained using stannous-2-ethyl hexanoate as catalyst in bulk. Reactivity ratios for the copolymerization of DXO and δ-VL were determined at 110°C as r_VL=0.5 and r_DXO=2.3. At high conversion, depolymerization of δ-VL occurred, resulting in lower molecular weight and variations in the copolymer composition.

Physical properties, such as crystallinity and melting temperature of the DXO-copolymers proved to be strongly dependent on the choice of comonomer and on the molar composition of the copolymers. DXO appears to be incorporated into the poly-?-caprolactone (PCL) crystals and to some extent into the poly-δ-valerolactone (PVL) crystals, resulting in a more gradual decrease in crystallinity with increasing amount of DXO.     

Divergent reactivity of allene-containing α-diazoesters using Cu and Rh catalysis

A versatile intramolecular reaction of allene-containing diazomalonates that exhibits excellent chemoselectivity for either allenic C–H insertion or cyclopropanation is demonstrated. The identity of the product depends on the transition metal catalyst that is employed for the reaction. Rh catalysts promote exclusive C–H insertion with good diastereoselectivity for the trans product, while Cu catalysis enables intramolecular cyclopropanation to yield methylenecyclopropanes with moderate to good E:Z ratios.     

Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides

We report a new visible-light-mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)₂(dtb-bpy)]⁺ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional-group tolerance, and enables the late-stage amidation of complex natural products.