Search results for "Conjugated system"

A Short Synthesis of Polysubstituted Pyrrolidines via α-(Alkylidene­amino)nitriles

2004

α-(Alkylideneamino)nitriles can be deprotonated under mild conditions. Their conjugated anions react with enones in a 1,4-addition to yield δ-keto-α-(alkylideneamino)nitriles which in turn can be reduced to form pyrrolidines in a one-pot reaction sequence.

Thermal Induction of 9t12t Linoleic Acid: a New Pathway for the Formation of Conjugated Linoleic Acids

2009

Accepted version of an article published in the journal: International Journal of Engineering and Technology Published version available at: http://www.ijetch.org/papers/066.pdf Thermal induction of 9t12t fatty acid leading to the formation of Conjugated Linoleic Acids (CLA) has been demonstrated by subjecting glyceride, and methyl ester of the acid to heat treatment. Fifteen micro liter portions of the glyceride sample containing 9t12t fatty acid (trilinoelaidin) were placed in micro glass ampoules and sealed under nitrogen and then subjected to thermal treatment at 250oC. The glass ampoules were taken out at regular time intervals, and the contents were subjected to composition analysis b…

MRI-visible nanoparticles from hydrophobic gadolinium poly(ε-caprolactone) conjugates

2015

International audience; In this work we report on the synthesis of two hydrophobic and degradable gadolinium poly(ε-caprolactone) conjugates and their use for the preparation of MRI-visible nanoparticles intended for diagnosis applications. Advantage has been taken from functional poly(ε-caprolactone)s (PCL) bearing propargyl (PCL-yne) or amine groups (P(CL-co-NH2VL)) to yield conjugates by following two strategies. In a first approach, an azido-chelate of gadolinium (Gd(III)) has been conjugated by CuAAC to PCL-yne to yield a polymeric chelate containing 2.6 wt% of Gd(III). In a second approach, a dianhydride Gd(III)-ligand was reacted with P(CL-co-NH2VL) to yield, after complexation with …

Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media

2018

International audience; A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central c…

Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives

2021

Series of highly polar stilbene (1a–e), diphenylbutadiene (2a–c) and phenylethenylthiophene (3a–c) derivatives were prepared via Horner–Wadsworth–Emmons method with a view to produce new and efficient materials for second harmonic generation (SHG) in the solid-state. The single-crystal X-ray structures of compounds 1–3 reveal extensive polymorphism and a peculiar photodimerization of the 2-chloro-3,4-dimethoxy-4′-nitrostilbene derivative 1a to afford two polymorphs of tetra-aryl cyclobutane 4. The stilbene congeners 2-chloro-3,4-dimethoxy-4′-nitrostilbene (1a·non-centro), 5-bromo-2-hydroxy-3-nitro-4′-nitrostilbene (1b) and 4-dimethylamino-4′-nitrostilbene (1e), as well as 4′-fluoro-4′′-nitr…

Metallomacrocycles with metalmetal bonds: synthesis, characterization and electrochemistry of [(P)SnRe(CO)5]BF4 and [{(P)Sn}2Re(CO)4]BF4 derivatives…

1996

Abstract The synthesis and characterization of bimetallic and trimetallic porphyrins of the type [(P)SnRe(CO) 5 ]BF 4 and [{(P)Sn} 2 Re(CO) 4 ]BF 4 are reported where P is the dianion of tetra- p -tolyporphyrin (TpTP) or tetra- m -tolyporphyrin (TmTP). These metal-metal bonded complexes were synthesized by reaction of Re 2 (CO) 10 with the corresponding (P)SnCl 2 derivatives in 1,2-dichlorobenzene followed by a reaction with NaBF 4 or TBABF 4 in toluene to give the BF − 4 salt. Each compound was characterized by a variety of spectroscopic and electrochemical techniques while the structures were assigned on the basis of FAB mass spectral data and by comparison of their physicochemical proper…

The Structural Diversity of Benzofuran Resorcinarene Leads to Enhanced Fluorescence

2014

An unexpected and previously unknown resorcinarene mono-crown with a fused benzofuran moiety in its macrocyclic core was obtained as a byproduct from a bridging reaction of tetramethoxy resorcinarene with tetraethylene glycol ditosylate. The formation of the fused benzofuran moiety in the resorcinarene macrocycle resulted in a unique rigid and puckered boat conformation, as shown by XRD studies in the solid state. Modification of the macrocycle was also observed to affect the photophysical properties in solution by enhancing the fluorescence brightness compared with a conventional resorcinarene macrocycle. The fluorescent properties enabled unique detection of structural features, that is, …

Copper-Catalyzed One-Pot Synthesis of 3-(N -Heteroarenyl)acrylonitriles through Radical Conjugated Addition of β-Nitrostyrene to Methylazaarenes

2020

Cycloalkin-vinylidencycloalkan-umlagerungen

1989

Abstract Flash pyrolysis of the strained cyclic alkynes 1 leads to ring systems 2 with an exocyclic allene group and in a further isomerization step to the conjugated vinyl compounds 3 .

Anthracene Based Conjugated Polymers: Correlation between π−π-Stacking Ability, Photophysical Properties, Charge Carrier Mobility, and Photovoltaic P…

2010

This article reports on the synthesis, characterization and properties of a series of anthracene−containing poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene)s (PPE−PPV) copolymers with general constitutional unit (Ph−C≡C−Anthr−C≡C−Ph−CH═CH−Ph−CH═CH−)n denoted AnE-PV. Solely linear (AnE-PVaa, -ad, -ae) and solely branched (AnE-PVbb) as well as mixed linear and branched (AnE-PVab, -ac, -ba, -cc) alkoxy side chains were grafted to the backbone in order to tune the π−π-stacking ability of the materials. It has been possible to establish a correlation between π−π-stacking ability, absorptive behavior, charge carrier mobility, solar cell active layer nanoscale morphology and resulting p…