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1.
Acid/Base‐Triggered Switching of Circularly Polarized Luminescence and Electronic Circular Dichroism in Organic and Organometallic Helicenes 下载免费PDF全文
Nidal Saleh Barry Moore II Monika Srebro Nicolas Vanthuyne Loïc Toupet J. A. Gareth Williams Christian Roussel Kirandeep K. Deol Gilles Muller Jochen Autschbach Jeanne Crassous 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(4):1673-1681
Electronic circular dichroism and circularly polarized luminescence acid/base switching activity has been demonstrated in helicene‐bipyridine proligand 1 a and in its “rollover” cycloplatinated derivative 2 a . Whereas proligand 1 a displays a strong bathochromic shift (>160 nm) of the nonpolarized and circularly polarized luminescence upon protonation, complex 2 a displays slightly stronger emission. This strikingly different behavior between singlet emission in the organic helicene and triplet emission in the organometallic derivative has been rationalized by using quantum‐chemical calculations. The very large bathochromic shift of the emission observed upon protonation of azahelicene‐bipyridine 1 a has been attributed to the decrease in aromaticity (promoting a charge‐transfer‐type transition rather than a π–π* transition) as well as an increase in the HOMO–LUMO character of the transition and stabilization of the LUMO level upon protonation. 相似文献
2.
Romain Plais Guy Gouarin Dr. Anne Gaucher Violette Haldys Arnaud Brosseau Dr. Gilles Clavier Dr. Jean-Yves Salpin Prof. Dr. Damien Prim 《Chemphyschem》2020,21(12):1249-1257
The intrinsic properties of tetrazine as a π-anion receptor and as an on/off recognition probe merged with H-bond ability of an urea motif into a single architecture constitutes a new generation of well-defined anion receptors. Complexation properties directly benefit from the dual and synergistic contribution of tetrazine and urea. In this study, we report on the synthesis and assessment of binding properties to anions of diverse geometries. Association constants have been predicted by theoretical calculations and evaluated by multiple and complementary experimental techniques including electrospray-mass tandem spectroscopy, NMR, UV-visible, steady state fluorescence spectroscopies and time resolved fluorescence. These results provide the basis for a better understanding of both the complexation and the anion-dependent quenching mechanism. 相似文献
3.
Dr. Anna Notaro Marta Jakubaszek Severin Koch Dr. Riccardo Rubbiani Dr. Orsolya Dömötör Dr. Éva A. Enyedy Mazzarine Dotou Dr. Fethi Bedioui Mickaël Tharaud Dr. Bruno Goud PD Dr. Stefano Ferrari Prof. Dr. Enzo Alessio Dr. Gilles Gasser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4997-5009
Cancer is one of the main causes of death worldwide. Chemotherapy, despite its severe side effects, is to date one of the leading strategies against cancer. Metal-based drugs present several potential advantages when compared to organic compounds and they have gained trust from the scientific community after the approval on the market of the drug cisplatin. Recently, we reported the ruthenium complex ([Ru(DIP)2(sq)](PF6) (where DIP is 4,7-diphenyl-1,10-phenantroline and sq is semiquinonate) with a remarkable potential as chemotherapeutic agent against cancer, both in vitro and in vivo. In this work, we analyse a structurally similar compound, namely [Ru(DIP)2(mal)](PF6), carrying the flavour-enhancing agent approved by the FDA, maltol (mal). To possess an FDA approved ligand is crucial for a complex, whose mechanism of action might include ligand exchange. Herein, we describe the synthesis and characterisation of [Ru(DIP)2(mal)](PF6), its stability in solutions and under conditions that resemble the physiological ones, and its in-depth biological investigation. Cytotoxicity tests on different cell lines in 2D model and on HeLa MultiCellular Tumour Spheroids (MCTS) demonstrated that our compound has higher activity than cisplatin, inspiring further tests. [Ru(DIP)2(mal)](PF6) was efficiently internalised by HeLa cells through a passive transport mechanism and severely affected the mitochondrial metabolism. 相似文献
4.
Dr. Julie Martin Dr. Mohammad Wehbi Dr. Cécile Echalier Dr. Sylvie Hunger Dr. Audrey Bethry Prof. Xavier Garric Dr. Coline Pinese Prof. Jean Martinez Dr. Lubomir Vezenkov Prof. Gilles Subra Prof. Ahmad Mehdi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(56):12839-12845
A simple and efficient way to synthesize peptide-containing silicone materials is described. Silicone oils containing a chosen ratio of bioactive peptide sequences were prepared by acid-catalyzed copolymerization of dichlorodimethylsilane, hybrid dichloromethyl peptidosilane, and Si(vinyl)- or SiH-functionalized monomers. Functionalized silicone oils were first obtained and then, after hydrosilylation cross-linking, bioactive polydimethylsiloxane (PDMS)-based materials were straightforwardly obtained. The introduction of an antibacterial peptide yielded PDMS materials showing activity against Staphylococcus aureus. PDMS containing RGD ligands showed improved cell-adhesion properties. This generic method was fully compatible with the stability of peptides and thus opened the way to the synthesis of a wide range of biologically active silicones. 相似文献
5.
Asma Mani Tao Feng Albert Gandioso Robin Vinck Anna Notaro Lisa Gourdon Pierre Burckel Bruno Saubaméa Olivier Blacque Kevin Cariou Jamel-Eddine Belgaied Hui Chao Gilles Gasser 《Angewandte Chemie (International ed. in English)》2023,62(20):e202218347
Five osmium(II) polypyridyl complexes of the general formula [Os(4,7-diphenyl-1,10-phenanthroline)2 L ]2+ were synthesized as photosensitizers for photodynamic therapy by varying the nature of the ligand L . Thanks to the pronounced π-extended structure of the ligands and the heavy atom effect provided by the osmium center, these complexes exhibit a high absorption in the near-infrared (NIR) region (up to 740 nm), unlike related ruthenium complexes. This led to a promising phototoxicity in vitro against cancer cells cultured as 2D cell layers but also in multicellular tumor spheroids upon irradiation at 740 nm. The complex [Os(4,7-diphenyl-1,10-phenanthroline)2(2,2′-bipyridine)]2+ was found to be the most efficient against various cancer cell lines, with high phototoxicity indexes. Experiments on CT26 tumor-bearing BALB/c mice also indicate that the OsII complexes could significantly reduce tumor growth following 740 nm laser irradiation. The high phototoxicity in the biological window of this structurally simple complex makes it a promising photosensitizer for cancer treatment. 相似文献
6.
A Highly Effective Ruthenium System for the Catalyzed Dehydrogenative Cyclization of Amine–Boranes to Cyclic Boranes under Mild Conditions 下载免费PDF全文
Dr. Christopher J. Wallis Dr. Gilles Alcaraz Dr. Alban S. Petit Dr. Amalia I. Poblador‐Bahamonde Dr. Eric Clot Dr. Christian Bijani Dr. Laure Vendier Dr. Sylviane Sabo‐Etienne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):13080-13090
We recently disclosed a new ruthenium‐catalyzed dehydrogenative cyclization process (CDC) of diamine–monoboranes leading to cyclic diaminoboranes. In the present study, the CDC reaction has been successfully extended to a larger number of diamine–monoboranes ( 4 – 7 ) and to one amine–borane alcohol precursor ( 8 ). The corresponding NB(H)N‐ and NB(H)O‐containing cyclic diaminoboranes ( 12 – 15 ) and oxazaborolidine ( 16 ) were obtained in good to high yields. Multiple substitution patterns on the starting amine–borane substrates were evaluated and the reaction was also performed with chiral substrates. Efforts have been spent to understand the mechanism of the ruthenium CDC process. In addition to a computational approach, a strategy enabling the kinetic discrimination on successive events of the catalytic process leading to the formation of the NB(H)N linkage was performed on the six‐carbon chain diamine–monoborane 21 and completed with a 15N NMR study. The long‐life bis‐σ‐borane ruthenium intermediate 23 possessing a reactive NHMe ending was characterized in situ and proved to catalyze the dehydrogenative cyclization of 1 , ascertaining that bis σ‐borane ruthenium complexes are key intermediates in the CDC process. 相似文献
7.
Frontispiece: EPR Studies of the Binding Properties,Guest Dynamics,and Inner‐Space Dimensions of a Water‐Soluble Resorcinarene Capsule 下载免费PDF全文
8.
MgI2‐Mediated Chemoselective Cleavage of Protecting Groups: An Alternative to Conventional Deprotection Methodologies 下载免费PDF全文
Mathéo Berthet Florian Davanier Dr. Gilles Dujardin Prof. Jean Martinez Dr. Isabelle Parrot 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11014-11016
The scope of MgI2 as a valuable tool for quantitative and mild chemoselective cleavage of protecting groups is described here. This novel synthetic approach expands the use of protecting groups, widens the concept of orthogonality in synthetic processes, and offers a facile opportunity to release compounds from solid supports. 相似文献
9.
EPR Studies of the Binding Properties,Guest Dynamics,and Inner‐Space Dimensions of a Water‐Soluble Resorcinarene Capsule 下载免费PDF全文
Dr. Mehmet Menaf Ayhan Dr. Gilles Casano Dr. Hakim Karoui Prof. Antal Rockenbauer Dr. Valérie Monnier Dr. Micaël Hardy Prof. Paul Tordo Dr. David Bardelang Dr. Olivier Ouari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16404-16410
Nitroxide free radicals have been used to study the inner space of one of Rebek’s water‐soluble capsules. EPR and 1H NMR spectroscopy, ESI‐MS, and DFT calculations showed a preference for the formation of 1:2 complexes. EPR titrations allowed us to determine binding constants (Ka) in the order of 107 M ?2. EPR spectral‐shape analysis provided information on the guest rotational dynamics within the capsule. The interplay between optimum hydrogen bonding upon capsule formation and steric strain for guest accommodation highlights some degree of flexibility for guest inclusion, particularly at the center of the capsule where the hydrogen bond seam can be barely distorted or slightly disturbed. 相似文献
10.
α‐Peptide–Oligourea Chimeras: Stabilization of Short α‐Helices by Non‐Peptide Helical Foldamers 下载免费PDF全文
Dr. Juliette Fremaux Laura Mauran Dr. Karolina Pulka‐Ziach Dr. Brice Kauffmann Dr. Benoit Odaert Dr. Gilles Guichard 《Angewandte Chemie (International ed. in English)》2015,54(34):9816-9820
Short α‐peptides with less than 10 residues generally display a low propensity to nucleate stable helical conformations. While various strategies to stabilize peptide helices have been previously reported, the ability of non‐peptide helical foldamers to stabilize α‐helices when fused to short α‐peptide segments has not been investigated. Towards this end, structural investigations into a series of chimeric oligomers obtained by joining aliphatic oligoureas to the C‐ or N‐termini of α‐peptides are described. All chimeras were found to be fully helical, with as few as 2 (or 3) urea units sufficient to propagate an α‐helical conformation in the fused peptide segment. The remarkable compatibility of α‐peptides with oligoureas described here, along with the simplicity of the approach, highlights the potential of interfacing natural and non‐peptide backbones as a means to further control the behavior of α‐peptides. 相似文献