We present a study of microphase separation induced by competitive hydrogen bonding in A-b-B/C diblock copolymer/homopolymer complexes where the diblock copolymer A-b-B is immiscible and the homopolymer C can interact unequally with both A and B blocks through hydrogen bonding. A model system containing poly(2-vinyl pyridine)-block-poly(methyl methacrylate) (P2VP-b-PMMA) and poly(4-vinyl phenol...

Sodium borohydride is a well known reducing agent. In methanol at room temperature formyl and keto groups are readily reduced to alcohol groups, while ester and carboxyl groups, carbon-carbon and carbon-nitrogen double bonds are only reduced with difficulty (2, 17). Of the groups present in chlorophyll b the C3 formyl and the C9 keto groups should be amenable to reduction, while the C2 vinyl an...

The reaction between tetrakis(triethylphosphine)platinum(0) and 4-[trans-2-(4-bromophenyl)vinyl]pyridine (1) is examined. Initially, the metal center coordinates to the bridging double bond of 1. Complexes 2 and 3 were fully characterized, and their X-ray crystallography structures are presented. Upon heating, either in solution or in the solid state, complex 2 undergoes C-Br oxidative addition...

Sugar-based hydrogels were prepared by non-selective modification of sucrose with the introduction of vinyl groups. Sucrose was reacted with glycidyl methacrylate (1:1 molar ratio) in DMSO and in the presence of 4-(N,N-dimethylamino)pyridine (4-DMAP) as catalyst. The structure of the product (SucMA) was established using H NMR, H DQF-COSY NMR and C NMR analysis. Gels were prepared by copolymeri...

Novel water-soluble lanthanide complexes (Ln(IMI-DPA)3) have been synthesized using the task-specific ionic liquid consisting of a dipicolinic acid motif as the sensitizer of lanthanide luminescence. In Ln(IMI-DPA)3, Ln(3+) ions are in 9-fold coordination through six carboxylate oxygen atoms and three nitrogen atoms in pyridine units, and the water molecule is excluded from the coordination sph...

N-Substituted pyridinium salts constitute one of the most valuable reagent classes in organic synthesis, due to their versatility and ease of use. Herein we report a preliminary synthesis and detailed structural analysis of several N-(1-ethoxyvinyl)pyridinium triflates, an unusual class of pyridinium salts with potentially broad use as a reagent in organic synthesis. Treatment of pyridines with...

A novel OH(-)-promoted tandem reaction involving C(β)-N(+)(pyridinium) cleavage and ether C(β)-O(oxime) bond formation in aqueous media has been presented. The study fully elucidates the fascinating reaction behavior of N-benzoylethylpyridinium-4-oxime chloride in aqueous media under mild reaction conditions. The reaction journey begins with the exclusive β-elimination and formation of pyridine...

Specific heat spectroscopy was used to study the dynamic glass transition of ultrathin poly(2-vinyl pyridine) films (thicknesses: 405-10 nm). The amplitude and the phase angle of the differential voltage were obtained as a measure of the complex heat capacity. In a traditional data analysis, the dynamic glass transition temperature Tg is estimated from the phase angle. These data showed no thic...

We investigated the use of functionalized photonic block copolymer films for the detection of glucose. Polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymers were chemically functionalized with 2-(bromomethyl)phenylboronic acid and cast into films that reflect a visible color when exposed to aqueous media. The 2-(bromomethyl)phenylboronic acid functionality can reversibly bind to glu...