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71.
Photoisomerisation in Aminoazobenzene‐Substituted Ruthenium(II) Tris(bipyridine) Complexes: Influence of the Conjugation Pathway 下载免费PDF全文
Dr. Anissa Amar Dr. Paul Savel Dr. Huriye Akdas‐Kilig Dr. Claudine Katan Prof. Hacène Meghezzi Prof. Abdou Boucekkine Dr. Jean‐Pierre Malval Dr. Jean‐Luc Fillaut 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8262-8270
Transition‐metal complexes containing stimuli‐responsive systems are attractive for applications in optical devices, photonic memory, photosensing, as well as luminescence imaging. Amongst them, photochromic metal complexes offer the possibility of combining the specific properties of the metal centre and the optical response of the photochromic group. The synthesis, the electrochemical properties and the photophysical characterisation of a series of donor–acceptor azobenzene derivatives that possess bipyridine groups connected to a 4‐dialkylaminoazobenzene moiety through various linkers are presented. DFT and TD‐DFT calculations were performed to complement the experimental findings and contribute to their interpretation. The position and nature of the linker (ethynyl, triazolyl, none) were engineered and shown to induce different electronic coupling between donor and acceptor in ligands and complexes. This in turn led to strong modulations in terms of photoisomerisation of the ligands and complexes. 相似文献
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Eva Lucaccini Matteo Briganti Dr. Mauro Perfetti Dr. Laure Vendier Dr. Jean‐Pierre Costes Dr. Federico Totti Prof. Dr. Roberta Sessoli Prof. Dr. Lorenzo Sorace 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(16):5552-5562
The magnetic behaviour of a Dy(LH)3 complex (LH? is the anion of 2‐hydroxy‐N′‐[(E)‐(2‐hydroxy‐3‐methoxyphenyl)methylidene]benzhydrazide) was analysed in depth from both theoretical and experimental points of view. Cantilever torque magnetometry indicated that the complex has Ising‐type anisotropy, and provided two possible directions for the easy axis of anisotropy due to the presence of two magnetically non‐equivalent molecules in the crystal. Ab initio calculations confirmed the strong Ising‐type anisotropy and disentangled the two possible orientations. The computed results obtained by using ab initio calculations were then used to rationalise the composite dynamic behaviour observed for both pure DyIII phase and YIII diluted phase, which showed two different relaxation channels in zero and non‐zero static magnetic fields. In particular, we showed that the relaxation behaviour at the higher temperature range can be correctly reproduced by using a master matrix approach, which suggests that Orbach relaxation is occurring through a second excited doublet. 相似文献
74.
Alkoxyallene‐ynes: Selective Preparation of Bicyclo[5.3.0] Ring Systems Including a δ‐Alkoxy Cyclopentadienone 下载免费PDF全文
Dr. Aurélien Tap Camille Lecourt Sabrina Dhambri Mathieu Arnould Dr. Gilles Galvani Dr. Olivier Nguyen Van Buu Dr. Morgan Jouanneau Dr. Jean‐Pierre Férézou Prof. Janick Ardisson Dr. Marie‐Isabelle Lannou Dr. Geoffroy Sorin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4938-4944
The development of an intramolecular rhodium(I)‐catalyzed Pauson–Khand reaction of alkoxyallene‐ynes with a proximal alkoxy group is reported. This reaction, in the presence of a [Rh(cycloocta‐1,5‐diene)Cl]2/propane‐1,3‐diylbis(diphenylphosphane) system under a CO atmosphere, constitutes a powerful tool for selectively accessing carbo‐ and heterobicyclo[5.3.0] frameworks featuring an enol ether moiety. Through this procedure, a straightforward access to guaiane skeletons with a tertiary hydroxy group at the C10 position was achieved. 相似文献
75.
Powder‐XRD and 14N magic angle‐spinning solid‐state NMR spectroscopy of some metal nitrides 下载免费PDF全文
Some metal nitrides (TiN, ZrN, InN, GaN, Ca3N2, Mg3N2, and Ge3N4) have been studied by powder X‐ray diffraction (XRD) and 14N magic angle‐spinning (MAS) solid‐state NMR spectroscopy. For Ca3N2, Mg3N2, and Ge3N4, no 14N NMR signal was observed. Low speed (νr = 2 kHz for TiN, ZrN, and GaN; νr = 1 kHz for InN) and ‘high speed’ (νr = 15 kHz for TiN; νr = 5 kHz for ZrN; νr = 10 kHz for InN and GaN) MAS NMR experiments were performed. For TiN, ZrN, InN, and GaN, powder‐XRD was used to identify the phases present in each sample. The number of peaks observed for each sample in their 14N MAS solid‐state NMR spectrum matches perfectly well with the number of nitrogen‐containing phases identified by powder‐XRD. The 14N MAS solid‐state NMR spectra are symmetric and dominated by the quadrupolar interaction. The envelopes of the spinning sidebands manifold are Lorentzian, and it is concluded that there is a distribution of the quadrupolar coupling constants Qcc's arising from structural defects in the compounds studied. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Synthesis,Electronic Properties and WOLED Devices of Planar Phosphorus‐Containing Polycyclic Aromatic Hydrocarbons 下载免费PDF全文
Dr. François Riobé Rózsa Szűcs Dr. Pierre‐Antoine Bouit Dr. Denis Tondelier Bernard Geffroy Fátima Aparicio Julia Buendía Prof. Luis Sánchez Prof. Régis Réau Prof. László Nyulászi Prof. Muriel Hissler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6547-6556
We describe the synthesis and the physical properties of polyaromatic hydrocarbons (PAHs) containing a phosphorus atom at the edge. In particular, the impact of the successive addition of aromatic rings on the electronic properties was investigated by experimental (UV/Vis absorption, fluorescence, cyclic voltammetry) and theoretical studies (DFT). The physical properties recorded in solution and in the solid state showed that the P‐containing PAHs exhibit properties expected for an emitter in white organic light‐emitting diodes (WOLEDs). 相似文献
78.
Iron complexes as photoinitiators for radical and cationic polymerization through photoredox catalysis processes 下载免费PDF全文
Jing Zhang Damien Campolo Frederic Dumur Pu Xiao Jean Pierre Fouassier Didier Gigmes Jacques Lalevée 《Journal of polymer science. Part A, Polymer chemistry》2015,53(1):42-49
Six iron complexes (FeCs) with various ligands have been designed and synthesized. In combination with additives (e.g., iodonium salt, N‐vinylcarbazole, amine, or chloro triazine), the FeC‐based systems are able to efficiently generate radicals, cations, and radical cations on a near UV or visible light‐emitting diode (LED) exposure. These systems are characterized by an unprecedented reactivity, that is, for very low content 0.02% FeC‐based systems is still highly efficient in photopolymerization contrary to the most famous reference systems (Bisacylphosphine oxide) illustrating the performance of the proposed catalytic approach. This work paves the way for polymerization in soft conditions (e.g., on LED irradiation). These FeC‐based systems exhibit photocatalytic properties, undergo the formation of radicals, radical cations, and cations and can operate through oxidation or/and reduction cycles. The photochemical mechanisms for the formation of the initiating species are studied using steady state photolysis, cyclic voltammetry, electron spin resonance spin trapping, and laser flash photolysis techniques. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 42–49 相似文献
79.
Aurica Farcas Giulia Tregnago Ana‐Maria Resmerita Sarah Taleb Dehkordi Sophie Cantin Fabrice Goubard Pierre‐Henri Aubert Franco Cacialli 《Journal of polymer science. Part A, Polymer chemistry》2014,52(4):460-471
The photophysical properties of two polyrotaxanes ( PFBTh?PSβCD and PFBTh?PMeβCD ) composed of fluorene and bithiophene encapsulated into permodified β‐cyclodextrin cavities have been investigated and compared with those of the reference PFBTh . Rotaxane formation results in improvements of the thermal stability, solubility in common organic solvents, as well as better film forming ability combined with a high transparency. As expected PFBTh and its encapsulated forms absorb at wavelengths beyond 510 nm, and time‐resolved photoluminescence (PL) in solution shows a well‐define vibronic structures with a predominance of the 0‐0 transitions and an energy difference of 0.16 eV. The fluorescence lifetimes follow a monoexponential decay with a value τ = 630 ± 30 ps. Atomic force microscopy, AFM, indicated a tendency of polyrotaxanes to organize into fibers. The advancing contact angles indicated higher surface hydrophobicity and lower surface free‐energy values for polyrotaxanes compared with their unthreaded analogues. The device based on PFBTh?PSβCD: PCBM in a 1/1 w/w ratio under simulated AM 1.5G illumination at 100 mW cm?2 exhibited improved photovoltaic parameters of cells, resulted in high Voc (0.68 V), Jsc (1.65 mA cm?2), FF (31.6%), and PCE (0.35) values, compared with PFBTh or PFBTh?PMeβCD , respectively. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 460–471 相似文献
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