Les complexes de platine ont été abondamment étudiés depuis la description de l'effet trans par le chercheur russe Chernayev. Cependant, les complexes de platine contenant la pyrazine ou la pyrimidine non substituées sont rares. De nouveaux types de complexes cis et trans de platine(II) contenant des ligands mixtes, Pt(Ypy)(pz/pm)CI₂, (où Ypy =dérivé de la pyridine, pz=pyrazine et pm=pyrimidine) ont été synthétisés par la réaction de K[Pt(Ypy)Cl₃] avec (pz/pm) en milieu aqueux dans des proportions 1:1. La même synthèse dans des proportions 2:1 a conduit à des dimères où le ligand pyrazine/pyrimidine forme un pont mettant en jeu ses deux atomes d'azote dans des liaisons de coordination. Seuls les isomères trans,trans-CI₂(Ypy)Pt(µ-pz/pm)Pt(Ypy)Cl₂ ont pu être isolés. Tous les complexes ont été caractérisés par spectroscopies IR et de résonance magnétique multinucléaire (¹⁹⁵Pt, ¹H et ¹³C). La spectroscopie infrarouge (v(Pt-Cl)) ainsi que ks constantes de couplage J(¹⁹⁵Pt-¹H) et J(¹⁹⁵Pt-¹³C) donnent des informations sur la géométrie des complexes. En effet, un signal unique est observé dans la région des élongations v(Pt-CI) pour les complexes trans et deux pour ceux de configuration cis. D'autre part, les constantes de couplage ³J(¹⁹⁵Pt-¹H) sont un peu plus grandes pour les complexes de géométries cis que pour ceux de configuration trans. Les valeurs des déplacements chimiques en RMN du ¹⁹⁵Pt donnent des informations sur la densité électronique autour du platine, celles en RMN ¹H et ¹³C sur celles des ligands. L'influence de la position des groupements méthyle sur le noyau pyridine a été étudiée grâce à ces méthodes spectroscopiques. Les complexes comportant des dérivés de la pyridine substitués en 2 et en 6 montrent des résonances à plus faibles champs en RMN ¹⁹⁵Pt ce qui a été attribué à l'effet de solvant. Les signaux en RMN ¹⁹⁵Pt des monomères cis ont été observés à des champs plus élevés que ceux des analogues trans. Les dimères trans ont été observés à des champs semblables (complexes de la pyrimidine) ou un peu plus faibles (complexes de la pyrazine) que les monomères trans. Ces résultats ne plaident pas en faveur d'une rétrodonation importante Pt→N. Toutefois, les résultats en spectroscopie RMN ¹⁹⁵Pt résultent d'un ensemble de plusieurs effets électroniques, qui sont difficiles à séparer. Si donc une rétrodonation existe, elle serait faible comparativement à celle observée avec des ligands sulfoxyde ou phosphine. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Platine, Pyridine, Pyrazine, Pyrimidine, RMN, Infrarouge, Effet de solvant.

We use stepwise [3+3] annulation to prepare the asymmetric glutarimides, and then establish a new approach to isoquinolone skeleton starting from glutarimides via regioselective nucleophilic addition and ring-closing metathesis reaction. Finally, we applied this method to the synthetic studies toward (¡Ó)-Xylopinine.

We can construct asymmetric glutarimide while using [3+3] annulation.Then we can build substituent group in C6 position after choosing regioselective addition reaction, and then apply it to synthetic studies toward polysubstituted pyridin-2-ones and Vitamin B6 derivatives.

Solid-state complexes between diblock copolymer and amphiphilic surfactant (surf) results in polymers characterized by two length scales with one macroscopic ¡§block copolymer length¡¨ and one mesomorphic ordered ¡§nanoscale¡¨. In this study, the desired polymer was prepared by complexing the surf molecules, i.e., 4-dodecylbenzenesulfonic acid (DBSA), with polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) and a comb-coil A-block-(B-graft-C) type copolymer can be generated through a supramolecular assembly route. On the block copolymer scale, the PS blocks are phase-separation from the P4VP(DBSA)x block, which x denotes the molar ratio between DBSA and pyridine groups. Bonding interaction between PS-b-P4VP and DBSA was conformed by FTIR. PLM was used to detect the mesomorphic structure within P4VP(DBSA)x block. In all cases, we found that birefringent can be only found in copolymer with their comb content exceeding 63 wt%. In the thermal analysis, shows us that the glasses transition temperature(Tgs) of the P4VP(DBSA)x block increases with the increasing DBSA content, a result related to the stiffening of the P4VP main chain due to dense packing. On the mesomorphic nanoscale, wide-angle X-ray diffraction study suggests an ordered supramolecular layer structure was formed in most of the complexation cases, in which the thicknesses of the polymer and surf layers were determined from the one-dimensional correlation function. The result indicates that both layers thickness increase with increasing DBSA amounts due to the stretching of the long alkyl tail in DBSA. Finally, macroscopic morphology varied with the DBSA content according to TEM results.

<p>This thesis deals with the preparation and use of chiralbispyridylamides as ligands in metal-catalyzed asymmetricreactions.</p><p>The compounds were prepared by amide formation usingdifferent coupling reagents. Bispyridylamides havingsubstituents in the 4- or 6- positions of the pyridine ringswere prepared by functional group interconversion of the 4- or6- halopyridine derivatives. These synthetic approaches provedto be useful for various types of chiral backbones. Pseudo C₂-symmetric bispyridylamides were also synthesizedby means of stepwise amide formation.</p><p>The compounds were used as ligands in themicrowave-accelerated Mocatalyzed asymmetric allylic alkylationreaction. Ligands having ð-donating substituents in the4-positions of the pyridine rings gave rise to products withhigher branched to linear ratio. The catalytic reaction, whichproved to be rather general for allylic carbonates with anaromatic substituent, was used as the key step in thepreparation of (R)-baclofen. The Mo-bispyridylamide catalystprecursor was studied by NMR spectroscopy.</p><p>Bispyridylamide complexes of metal alkoxides were alsoevaluated in the asymmetric addition of cyanide to aldehydesand the metal complexes involved were studied by NMRspectroscopy and X-ray crystallography. Chiral diamines wereused as additives to study the ring opening of cyclohexeneoxide with azide, catalyzed by Zr(IV)-bispyridylamidecomplexes.</p><p>Various bispyridylamides were attached to solid supports oforganic or inorganic nature. The solid-supported ligands wereused in Mo-catalyzed asymmetric allylic alkylation reactionsand in the asymmetric addition of cyanide to benzaldehyde.</p><p><b>Keywords:</b>asymmetric catalysis, chiral ligand, pyridine,amide, allylic alkylation, enantioselective, cyanation,ring-opening, chiral Lewis acid.</p>

Reproduction de : Thèse de doctorat : Chimie organique et macromoléculaire : Lille 1 : 2005. / N° d'ordre (Lille 1) : 3769. Titre provenant de la page de titre du document numérisé. Bibliogr. p. 195-203. Notes bibliogr.

A study of the interactions of the specifically interacting organic compound pyridine with a model soil organic matter sorbent (Pahokee peat) was carried out from different nonaqueous organic liquid media, including neat n-hexadecane, acetonitrile, acetone and nhexadecane mixtures with either acetone or acetonitrile. Kinetic and equilibrium studies using an activity-based comparison of the organic compounds in solution was used to study the interactions of soil organic matter (SOM) and pyridine sorption capability in the various non-aqueous organic liquid media. Quantification and qualification of pyridine and the other co-solvents were done using Gas Chromatography (GC). Sorption of pyridine from neat organic solvents was not masked by sorption of the organic solvent. The apparent sorbed amount calculated from the change in solute concentration and reported on a dry weight basis was considered to represent the true sorbed concentration of pyridine in the sorbent phase. Pyridine sorption was found to be non-linear and distribution coefficients decreased with solute concentration, by approximately three times in n-hexadecane, more than five times in acetonitrile, and by ten times in acetone over the experimental concentration range. Pyridine sorption from nhexadecane was also found to be comparable with sorbed amounts from acetone, but much lower in comparison to sorption from acetonitrile. Sorption of pyridine from n-hexadecane mixtures with acetonitrile or acetone demonstrated the solvent assisted effect of pyridine sorption. Sorption uptake of pyridine increased as initial acetonitrile concentration increased, this acetonitrile assisted trend for pyridine sorption was found in the presence of a large excess of n-hexadecane. Sorbed concentrations of pyridine measured in the presence of high concentrations of acetonitrile (close to it's solubility limit) were found to be very similar to pyridine sorption from neat acetonitrile. Sorption behaviour of pyridine in n-hexadecane-acetone mixtures showed that increasing acetone concentrations had no effect on pyridine sorption. Pyridine sorbed from n-hexadecane, n-hexadecane-acetonitrile, and n-hexadecaneacetone mixtures showed a hysteretic desorption to n-hexadecane. After a series of repeated solvent extractions with solvents of increasing solvating power(1,4-dioxane, ethanol, dimethylsulfoxide), a fraction of pyridine remained bound to the peat. This nonrecoverable fraction was approximately the same for the different organic media (OA5± 0.09 in n-hexadecane suspensions, 0.57±O.12 in n-hexadecane-acetonitrile mixtures, and OA6±0.07 in n-hexadecane-acetone mixtures). Acetonitrile sorption by peat from nhexadecane was found to be very non-linear and hysteretic. The acetonitrile sorbed was almost fully recoverable, around 90%, for the initial acetonitrile concentration range varying from 0.14-0.7% by volume. However in the presence of pyridine a significant portion of acetonitrile was not recovered even after multiple extractions of polar organic solvents. Pyridine irreversible binding was not induced by acetonitrile additions and was found to occur to the same extent in both neat n-hexadecane and n-hexadecane-acetone mixtures. The solubilities of acetonitrile and acetone were determined by the flask method at 25°C using GC analysis. Solubility in volume percent for acetonitrile in n-hexadecane, 0.9±0.07, 0.57±0.02 for n-hexadecane in acetonitrile, 24.0±OA for acetone in nhexadecane, and 13 A±O.2 for n-hexadecane in acetone, were found. Log Ostwald coefficient (1.63±O.02) for acetonitrile in n-hexadecane was measured at 25°C using head space analysis and was found to be constant in the acetonitrile concentration range 0.10.8% by volume. Log Ostwald coefficient for pyridine in hexadecane used was 3.02, for the pyridine concentration range 50 mgIL-500 mg/L, this value was constant even with 0.5% by volume additions of acetonitrile. Analyses of sorption isotherms were reported on an activity basis to eliminate the effect of differential solute interactions in the solvent, calculated using the solute equilibrium concentration, the concentration of saturated vapour, and the Ostwald coefficient. Dissolution of peat components into n-hexadecane are known to be negligible. Peat components extracted after 12 hours and 3,5 months acetonitrile and acetone treatment (solid liquid ratio 1: 10) Showed 15 to 20 times less visible absorbance respectively (A. 465, 620, and 665, E4:E6 ratios using DV-Visible Spectroscopy), than the 12 hours aqueous peat extract. Quantification of the dissolved humic materials in the aqueous extract was followed using a Total Organic Carbon analyser. The study found the degree of humification to be much lower in non-aqueous organic solvent extracts (2.5 for acetone extracts, and 3 for acetonitrile extracts) than in aqueous solution extracts (8.2). / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002. / The Moshe Greidinger Scholarship Fund.

Šilumos taikymas įvairioms ligoms gydyti jau buvo naudojamas senovės Egipto, Graikijos, Romos civilizacijose daugiau kaip prieš 2000 m. pr. Šiuo metu hipertermija plačiai taikoma visame pasaulyje gydant vėžį, nes tai pigus ir patogus metodas turintis mažą šalutinį poveikį. Mokslininkai nustatė, kad vėžinės ląstelės greičiau žūsta esant aukštesnei už fiziologinę (41-45°C) temperatūrai, todėl hipertermija, derinama su kitais vėžio gydymo metodais (radioterapija, chemoterapija, imunoterapija ir chirurgija), tampa efektyvesniu metodu. Kadangi yra mažai žinoma apie hipertermijos poveikio mechanizmą sveiko audinio ląstelėms karščiavimo, hiperterminio vėžio gydymo ar gydymo termoabliacija metu, todėl yra svarbu nustatyti hipertermijos paveiktų ląstelių gyvybingumą bei hipertermijos poveikį adenino ir piridino nukleotidų koncentracijoms. Šio darbo tikslas buvo įvertinti hipertermijos, būdingos nutolusioms nuo termozondo audinio sritims poveikį, adenino ir piridino nukleotidų koncentracijoms žiurkės kepenų ląstelėse bei audinyje. Buvo naudojamas jonų porų efektyviosios skysčių chromatografijos metodas, leidžiantis vienoje chromatografinėje analizėje išskirstyti labai skirtingo hidrofobiškumo junginius. Taip pat buvo vertintas gyvų ir negyvų ląstelių skaičius gautoje hepatocitų suspensijoje panaudojant tripano mėlio metodą bei NAD(P)H fluorescencijos pokyčiai kepenų audinyje termoabliacijos metu. Gauti rezultatai parodė, kad išskirti hepatocitai pasižymėjo dideliu gyvybingumu (8... [toliau žr. visą tekstą] / The application of heat in the treatment of disease was first recorded in the ancient civilizations of Egypt, Greece, and Rome from as early as 2000 BC. Nowadays hiperthermia is widely using in cancer diseases in all the world. It was determined by many scientists that cancer cells are more sensitive for supraphysiological temperature (41-45°C) killing compared to normal cells. There are numerous evidences that hyperthermia can increase the effectiveness of other cancer therapies: radiotherapy, chemotherapy, immunotherapy and surgery. There is little known about the mechanisms of hyperthermia effects on healthy tissue, which are important in fever, in hyperthermic treatment of neighboring tumour and in thermoablation. Therefore it is very important to determinate the vability of cells during different hyperthermic treatment and hyperthermic effects of adenine ir pyridine nucleotides concentrations.The aim of study was to value the effect of hyperthermia,which is typical remote from thermoprobe tissue areas, on the concentration of adenine and pyridine nucleotides in hepatocytes and liver tissue. It was used ion-pair high-performance liquid chromatography method, which allows to disperse different combinations of hydrophobicity. Also were evaluated live and dead cells quantity in the suspension through tripan blue method and NAD(P)H fluorescence changes in liver tissue during the ablation. The results showed that isolated hepatocytes exhibited with high viability (80%)... [to full text]

La compréhension de l'irradiation à l'échelle du nanomètre dans les systèmes biomoléculaires nécessite l'observation de caractéristiques nouvelles auxquelles les développements techniques actuels nous permettent d'accéder. Ce travail se situe au coeur de la construction du nouveau dispositif DIAM Dispositif d'Irradiation d'Agrégats de Molécules biologiques développé à l'Institut de Physique Nucléaire de Lyon. Le développement d'une source d'agrégats associée à un spectromètre de masse à double focalisation a permis l'obtention des premiers faisceaux d'agrégats moléculaires protonés sélectionnés en masse. De plus, un système de détection innovant a été développé et validé dans des expériences de dissociations d'agrégats d'eau protonés par collision sur un gaz. Les résultats obtenus contribuent à la connaissance de la stabilité et de la structure des petits agrégats d'eau protonés et des agrégats mixtes d'eau et de pyridine protonés

The infrared, Raman and ultraviolet spectra of pyridine-d0 and pyridine-d5 were recorded and assigned with a focus on the low-frequency vibrational modes in the S1(n,pi*) electronic excited state. An energy map for the low-frequency modes was constructed and the data for the v18 mode allowed a highly anharmonic one-dimensional potential energy function to be determined for the S1 excited state. In this S1(n,pi*) state, pyridine is quasi-planar and very floppy with a barrier to planarity of 3 cm^-1. The infrared, Raman and ultraviolet spectra of 2-fluoropyridine (2FPy) and 3-fluoropyridine (3FPy) have been collected and assigned. For 2FPy about 150 bands were observed for the transitions to the vibronic levels of the S(pi, pi*) state at 38,030.4 cm^-1. For 3FPy more than a hundred absorption bands associated with the S(n,pi*) state at 35,051.7 cm^-1 and about forty broad bands associated with the S(pi, pi*) state at 37,339 cm^-1 were observed. The experimental work was complemented by ab initio calculations and these also provided calculated structures for 2FPy, 3FPy, and pyridine. They showed that the fluorine atom on the ring participates in the pi bonding. The gas-phase Raman spectra of 1,3-butadiene and its 2,3-d2, 1,1,4,4-d4, and d6 isotopomers have been recorded with high sensitivity in the region below 350 cm-1, in order to investigate the internal rotation (torsional) vibration. The data for all the isotopomers were then fit using a one-dimensional potential energy function of the form V = (1/2)Sigma(Vn(1-cos (phi))). The energy difference between trans and gauche forms was determined to be about 1030 cm^-1 (2.94 kcal/mol), and the barrier between the two equivalent gauche forms to be about 180 cm^-1 (0.51 kcal/mol), which agrees well with high-level ab initio calculations. The results from an alternative set of assignments also fits the data quite well are also presented. Combination and hot band series involving the v13 torsional vibration of the trans rotamer were observed for each of the butadiene isotopomers. In addition, the high signal to noise of the Raman spectra made it possible to detect several dozen bands of the gauche rotor which makes up only about 2% of the molecules at ambient temperature.