Coordination entities of a pyrene-based iminopyridine ligand: Structural and photophysical properties
摘要:
A pyrene-based iminopyridine ligand L has been prepared and displays the absorption and emission properties expected for pyrene-based derivatives in solution. Ligand L, as well as two neutral and, one monocationic coordination entities, respectively formulated as [ZnLCl2] 1, [ReLCl(CO)(3)] 3 and [CuL2] (BF4) 2, have been crystallized and analyzed by single crystal X-ray diffraction analysis. The corresponding crystal structures indicate the formation of supramolecular architectures generated by offset pi...pi stacking between pyrene fragments and strong C-H center dot center dot center dot pi is interactions in coordination entity 1. For the cationic coordination entity 2, the crystal packing reveals the presence of C-H center dot center dot center dot F and C-H center dot center dot center dot pi interactions and numerous C-H center dot center dot center dot pi contacts interconnecting the molecules into a 3D network. As for coordination entity 3, hydrogen bonding and pi center dot center dot center dot pi stacking link the molecules in a three dimensional manner. Zinc(II) and copper(I) coordination entities have also been studied through isothermal titration calorimetry, which indicate a strong binding and a different stoichiometry for both coordination entities. Photophysical studies of the ligand and corresponding coordination entities show a monomer type pyrene emission and a higher fluorescence quantum yield for the zinc coordination entity 1 as compared with copper 2 and rhenium 3 coordination entities. (C) 2017 Elsevier Ltd. All rights reserved.
Unprecedented Comonomer Dependence of the Stereochemistry Control in Pd-Catalyzed CO/Vinyl Arene Polyketone Synthesis
作者:Giovanni Canil、Vera Rosar、Silvia Dalla Marta、Simona Bronco、Francesco Fini、Carla Carfagna、Jérôme Durand、Barbara Milani
DOI:10.1002/cctc.201500498
日期:2015.7.13
complexes generated active catalysts in the CO/vinyl arene copolymerization, leading to polyketones with yields and molecular weight strongly dependent on N‐N′, with the ketimine catalysts one order of magnitude more productive than the aldimine counterpart. The stereochemistry of polyketones synthesized with the aldimine catalyst was found to be dependent on the vinyl comonomer: prevailingly syndiotactic copolymers
Atropisomerism in a thermally switchable, cyclometallated iridium complex
作者:Ashlee J. Howarth、David L. Davies、Francesco Lelj、Michael O. Wolf、Brian O. Patrick
DOI:10.1039/c2dt31120h
日期:——
Two stable diastereomeric atropisomers of a cyclometallated iridium complex containing a pyrene functionalized pyridine imine ligand have been isolated. These are the first fully characterized examples of metal containing atropisomers in which the rotational axis is not between two chelating atoms. The atropisomers can be converted thermally via a rocking motion of the pyrene moiety.
Coordination entities of a pyrene-based iminopyridine ligand: Structural and photophysical properties
作者:Awatef Ayadi、Diana G. Branzea、Magali Allain、David Canevet、Haluk Dinçalp、Abdelkrim El-Ghayoury
DOI:10.1016/j.poly.2017.07.001
日期:2017.10
A pyrene-based iminopyridine ligand L has been prepared and displays the absorption and emission properties expected for pyrene-based derivatives in solution. Ligand L, as well as two neutral and, one monocationic coordination entities, respectively formulated as [ZnLCl2] 1, [ReLCl(CO)(3)] 3 and [CuL2] (BF4) 2, have been crystallized and analyzed by single crystal X-ray diffraction analysis. The corresponding crystal structures indicate the formation of supramolecular architectures generated by offset pi...pi stacking between pyrene fragments and strong C-H center dot center dot center dot pi is interactions in coordination entity 1. For the cationic coordination entity 2, the crystal packing reveals the presence of C-H center dot center dot center dot F and C-H center dot center dot center dot pi interactions and numerous C-H center dot center dot center dot pi contacts interconnecting the molecules into a 3D network. As for coordination entity 3, hydrogen bonding and pi center dot center dot center dot pi stacking link the molecules in a three dimensional manner. Zinc(II) and copper(I) coordination entities have also been studied through isothermal titration calorimetry, which indicate a strong binding and a different stoichiometry for both coordination entities. Photophysical studies of the ligand and corresponding coordination entities show a monomer type pyrene emission and a higher fluorescence quantum yield for the zinc coordination entity 1 as compared with copper 2 and rhenium 3 coordination entities. (C) 2017 Elsevier Ltd. All rights reserved.