581-46-4Relevant articles and documents
Boronic acid-based bipyridinium salts as tunable receptors for monosaccharides and α-hydroxycarboxylates
Gamsey, Soya,Miller, Aaron,Olmstead, Marilyn M.,Beavers, Christine M.,Hirayama, Lacie C.,Pradhan, Sulolit,Wessling, Ritchie A.,Singaram, Bakthan
, p. 1278 - 1286 (2007)
Several novel diboronic acid-substituted bipyridinium salts were prepared and, using a fluorescent reporter dye, were tested for their ability to selectively bind various monosaccharides and α-hydroxycarboxylates in an aqueous medium. The fluorescence sensing mechanism relies on the formation of a ground-state charge-transfer complex between the dye and bipyridinium. An X-ray crystal structure of this complex is described herein. Glucose selectivity over fructose and galactose was achieved by designing the bipyridinium-based receptors to be capable of attaining a 1:1 receptor/substrate stoichiometry via cooperative diboronic acid binding.
Photon-Induced Reactions of Aromatics Adsorbed on Rough and Smooth Silver Surfaces
Myli, K. B.,Coon, S. R.,Grassian, V. H.
, p. 16407 - 16415 (1995)
We have investigated the thermal and photon-induced chemistry of several aromatics adsorbed on smooth and roughtened Ag(111) surfaces at low temperatures (110 K).Pyrazine, pyridine, 3-chloropyridine, and chlorobenzene quantitatively desorb from Ag(111) near 200 K.After roughtening the surface with 2 kV Ar ion bombardment, the breadth of the molecular desorption curves increases, and there is a high-temperature tail due to desorption from defecty sites produced by the roughening process.Upon UV photolysis of 1 monolayer, chlorobenzene and 3-chloropyridine photodissociate on smooth and rough Ag surfaces, whereas no detectable photoreaction were observed for pyrazine or pyridine absorbed on either surface.For the molecules that did not undergo photodissociation, a shift to lower energy in the photodissociation threshold was observed on the rough surface relative to the smooth: 3.3 eV versus 3.5 eV for chlorobenzene and 3.5 eV versus 3.9 eV for 3-chloropyridine.We postulate that the decrease in the photodissociation threshold is due to defect sites produced by surface roughening, through either excitation of the surface plasmon resonance, which is allowed on the rough but not the smooth surface, or a more localized excitation near defect sites.Excitation in the molecular absorption band shows that the photodissociation yield is enhanced for 3-chloropyridine and quenched for chlorobenzene on the rough surface relative to the smooth.Theoretical calculations suggest that there is a decrease in the decay rate for 3-chloropyridine and an increase in the decay rate for chlorobenzene on the rough surface compared to smooth.Differences between the quenching rates for 3-chloropyridine and chlorobenzene may be related to the different molecular orientations of these two molecules on the surface.
Fluorinated Boronic Acid-Appended Bipyridinium Salts for Diol Recognition and Discrimination via 19F NMR Barcodes
Axthelm, J?rg,G?rls, Helmar,Schubert, Ulrich S.,Schiller, Alexander
, p. 15402 - 15405 (2015)
Fluorinated boronic acid-appended benzyl bipyridinium salts, derived from 4,4′-, 3,4′-, and 3,3′-bipyridines, were synthesized and used to detect and differentiate diol-containing analytes at physiological conditions via 19F NMR spectroscopy. An array of three water-soluble boronic acid receptors in combination with 19F NMR spectroscopy discriminates nine diol-containing bioanalytescatechol, dopamine, fructose, glucose, glucose-1-phosphate, glucose-6-phosphate, galactose, lactose, and sucroseat low mM concentrations. Characteristic 19F NMR fingerprints are interpreted as two-dimensional barcodes without the need of multivariate analysis techniques.
A General, Multimetallic Cross-Ullmann Biheteroaryl Synthesis from Heteroaryl Halides and Heteroaryl Triflates
Dibenedetto, Tarah A.,Kang, Kai,Loud, Nathan L.,Weix, Daniel J.
supporting information, p. 21484 - 21491 (2022/01/03)
Despite their importance to medicine and materials science, the synthesis of biheteroaryls by cross-coupling remains challenging. We describe here a new, general approach to biheteroaryls: the Ni-and Pd-catalyzed multimetallic cross-Ullmann coupling of he
Porphyrin n-pincer pd(Ii)-complexes in water: A base-free and nature-inspired protocol for the oxidative self-coupling of potassium aryltrifluoroborates in open-air
Hanafiah, Marlia M.,Lakkaboyana, Sivarama Krishna,Lakshmidevi, Jangam,Marella, Ravi Kumar,Naidu, Bandameeda Ramesh,Prasad, Sana Siva,Venkateswarlu, Katta
, (2021/09/13)
Metalloporphyrins (and porphyrins) are well known as pigments of life in nature, since representatives of this group include chlorophylls (Mg-porphyrins) and heme (Fe-porphyrins). Hence, the construction of chemistry based on these substances can be based on the imitation of biological systems. Inspired by nature, in this article we present the preparation of five different porphyrin, meso-tetraphenylporphyrin (TPP), meso-tetra(p-anisyl)porphyrin (TpAP), tetra-sodium meso-tetra(p-sulfonatophenyl)porphyrin (TSTpSPP), meso-tetra(m-hydroxyphenyl)porphyrin (TmHPP), and meso-tetra(m-carboxyphenyl)porphyrin (TmCPP) as well as their N-pincer Pd(II)-complexes such as Pd(II)-meso-tetraphenylporphyrin (PdTPP), Pd(II)-meso-tetra(p-anisyl)porphyrin (PdTpAP), Pd(II)-tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (PdTSTpSPP), Pd(II)-meso-tetra(m-hydroxyphenyl)porphyrin (PdTmHPP), and Pd(II)-meso-tetra(m-carboxyphenyl)porphyrin (PdTmCPP). These porphyrin N-pincer Pd(II)-complexes were studied and found to be effective in the base-free self-coupling reactions of potassium aryltrifluoroborates (PATFBs) in water at ambient conditions. The catalysts and the products (symmetrical biaryls) were characterized using their spectral data. The high yields of the biaryls, the bio-mimicking conditions, good substrate feasibility, evading the use of base, easy preparation and handling of catalysts, and the application of aqueous media, all make this protocol very attractive from a sustainability and cost-effective standpoint.
