Interaction of pyridine

Pyridine. Pyridine and its methyl substituted derivatives (picolines and lutidines) were found to polymerize electrochemically and, under certain circumstances, catalytically. This behavior was not expected because usually pyridine undergoes electrophilic substitution and addition slowly, behaving like a deactivated benzene ring. The interaction of pyridine with a Ni(100) surface did not indicate any catalytic polymerization. Adsorption of pyridine below 200 K resulted in pyridine adsorbing with the ring parallel to the surface. The infrared spectrum of pyridine adsorbed at 200 K showed no evidence of either ring vibrations or CH stretches (Figure 5). Desorption of molecular pyridine occurred at 250 K, and above 300 K pyridine underwent a... 

VOXj (X = Cl, Br, or I) react with (Pr 0)2MePO to form [V0 0(0)PMe-(OPr ) 2], which appears to be polymeric. The low steric interactions of pyridine 1-oxide and 4-methylpyridine 1-oxide (L ), combined with the weak nucleophilicity of the tetrafluoroborate anion, allow the formation of the... 

Thieno[3,4-d]azocine (78JHC193) 152 is formed as a result of intramolecular cyclization of 2-thienyltetrahydropyridine 151 produced by the interaction of pyridine quaternary salts 149 and thienylmagnesiumbromide with subsequent reduction. Under the action of the cyanogenbromide thienoazocines 152 are converted into their NH derivatives 153, subsequent alkylation allows the introduction of pharmacophoric substituents into the molecule (Scheme 41). 

Very interesting method of template polymerization was proposed by Japanese scientists. The method is based on the charge transfer interaction between template and monomer. In the course of the studies on the interaction of poly(maleic anhydride) with organic amines, the authors found strong charge transfer interaction of pyridines with poly(maleic anhydride). The polymer with pyridine gives brown-colored system with the absorption maximum at 480 nm. 

Although the interaction of pyridine and CINO3 has been reported83 to yield the [py2Cl]+ cation, there is as yet no crystallographic determination on a chlorine(I) compound. 

The main results to emerge from this study are that eo(0) ea(N) 4000 cm-1, an unexceptional value that e n(N), defined parallel to the plane of the sal groups, is zero - a chemically sensible result and that e i(N) 900 cm-1. This last figure shows that the nominally sp2 hybridized imine N atom enters into substantial rr interaction with the nickel atom, serving also to put the 100 cm 1 rr interaction of pyridine with Co/Fe above into perspective. 

Jacobs and Uytterhoeven (199, 200) observed a band in the 3700 to 3675 cm-1 region in addition to the bands reported by Ward. The intensities of the acidic bands at 3650 and 3550 cm-1 were greater than those observed by Ward, which probably resulted from a lesser degree of aluminum removal. The new bands at 3700 and 3600 cm-1 arose from hydroxyls that were nonacidic to ammonia (199, 200) and pyridine (198, 199), although bands from pyridinium ions were observed in the IR spectrum. The latter bands were attributed to interaction of pyridine with the 3650 cm-1 hydroxyls (200). Jacobs and Uytterhoeven (199) and Scherzer and Bass (198) attributed the 3700 and 3600 cm-1 bands to structural hydroxyl groups associated with removal of aluminum from the zeolite framework. The 3600 cm-1 band arose from weakly acidic hydroxyls (200) since the band was removed by treatment with 0.1 W NaOH solution. The 3700 cm-1 band was unaffected by a similar treatment. 

P. E. Eberly, Jr. No, we do not observe any shift in frequency of the 1438 cm" band with the nature of the rare earth ion. Thus, I believe the rare earth ions are inside the sodalite cage, not directly accessible to pyridine. Ward has suggested that the 1438 cm" band could arise from interaction of pyridine with the residual sodium ions in the supercage. 

Schwarz, Russell, and Harnsberger have developed a technique combining transmission infrared spectroscopy and temperature-programmed desorption and used it to study the interaction of pyridine with three silica-aluminas. On the 10 wt % AI2O3, acid sites were calculated to be 0.27 [xmole m (84% Lewis acid sites under experimental conditions). The activation energies for... 

The salt formed by the interaction of pyridine with mercuric acetate at room temperature can be rearranged to 3-acetoxymercuripyridine by heating to only 180 This process, where again there is C-attack by a relatively weakly electrophilic reagent, like that described for mercuric-sulfate-catalysed sulfonation, may involve attack on an equilibrium concentration of free pyridine. 

The possibility of interaction of pyridine with the dispersion matrix material was investigated by collecting spectra of pure KC1 and of pyridine adsorbed on pure KC1 before and after evacuation. All traces of pyridine were removed from the KC1 spectrum following a few minutes of evacuation. 

Stronger acid-base complexes with proton transfer induce formation of ion-pair systems leading to high dipole moments. The OH-N interactions of pyridine in... 

The pyridine hydrochloride is obtained as a thick precipitate, duly formed by the interaction of pyridine and HCl formed as a product of reaction. This has got to be removed and set apart. 

Already in the beginning of the history of concave reagents, the template effect of metal cations was utilized, but also organic molecules can be applied. Sanders for instance used the interaction of pyridines with zinc porphyrins in the construction of macrocyclic oligomeric porphyrins, and recently, the interaction between polyols and boronic acids has been used in order to synthesize new mdo-fimctionalized macrocycles (Figure 7.14) ... 

Hydrogen-bonding polymer networks can be even prepared in ionic liquids, as reported by Noro et al. [120]. In their work, an ABA triblock copolymer was synthesized containing end blocks that form hydrogen bonds with a specifically designed homopolymer via interactions of pyridine and hydroxy styrene. The prime role of the ionic liquid is to assure good solvent conditions over a wide range of... 

Tarasevich Y, Telichkun V and Ovcharenko F, Spectroscopic investigation of the interaction of pyridine with a montmorillonite surface , Theor. Exper. CAem., 1973,6,658-662. 

With regard to the interaction of pyridine rings with carbanionic species, the nature of the anionic pol)onerization of vinylpyrldines should be... 

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