Templated synthesis of a rotaxane with a [Ru(diimine)3]2+ core.
A rotaxane containing a ruthenium bisphenanthroline complex, acting as an axis, and a macrocycle incorporating a 2,2'-bipyridine (bpy) unit, threaded by the axis, has been synthesized. The bisphenanthroline ligand is such that its ruthenium(II) complexes possess a clearly identified axis, making such compounds ideal components of rotaxanes constructed around an octahedral ruthenium(II) center, which serves as a template. The ring is threaded by the axial ruthenium(II) precursor complex, to afford the corresponding pseudorotaxane in moderate yield. The X-ray structure analysis of this compound reveals the threaded nature of the complex. The length of the threaded ring (35 atoms in the periph…
A Functionalized Noncovalent Macrocyclic Multiporphyrin Assembly from a Dizinc(II) Bis-Porphyrin Receptor and a Free-Base Dipyridylporphyrin
The bis-porphyrin system ZnP 2 , in which two zinc porphyrins are connected by a phenanthroline linker in an oblique fashion, acts as a bifunctional receptor towards the complexation of free-base meso-5,10-bis(4'-pyridyl)-15,20-diphenylporphyrin (4'-cisDPyP). In solution, NMR spectroscopy evidenced quantitative formation of the tris-porphyrin macrocyclic assembly ZnP 2 (4'-cisDPyP), in which the two fragments are held together by two axial 4'-N(pyridyl)-Zn interactions. The remarkable stability of the edifice (an association constant of about 6 x 10 8 M - 1 was determined by UV/Vis absorption and emission titration experiments in toluene) is due to the almost perfect geometrical match betwe…
Photoinduced Electron Transfer in Multiporphyrinic Interlocked Structures: The Effect of Copper(I) Coordination in the Central Site
Photoinduced processes have been determined in a [2]catenane containing a zinc(II) porphyrin, a gold(III) porphyrin, and two free phenanthroline binding sites, Zn-Au(+), and in the corresponding copper(I) phenanthroline complex, Zn-Cu(+)-Au(+). In acetonitrile solution Zn-Au(+) is present in two different conformations: an extended one, L, which accounts for 40 % of the total, and a compact one, S. In the L conformation, the electron transfer from the excited state of the Zn porphyrin to the gold-porphyrin unit (k = 1.3x10(9) s(-1)) is followed by a slow recombination (k = 8.3x10(7) s(-1)) to the ground state. The processes in the S conformation cannot be clearly resolved but a charge-separ…
Templated synthesis of a large and flexible covalent porphyrinic cage bearing orthogonal recognition sites.
A large covalent cage incorporating two porphyrins attached by four long and flexible polyether chains each bearing two 3-pyridyl ligands was synthesized from a DABCO-templated olefin metathesis reaction. The X-ray structure of the cage with the DABCO coordinated inside the cavity to the two zinc(II) porphyrins reveals a highly symmetric structure.
Frontispiece: Positive Allosteric Control of Guests Encapsulation by Metal Binding to Covalent Porphyrin Cages
Positive Allosteric Control of Guests Encapsulation by Metal Binding to Covalent Porphyrin Cages
The allosteric control of the receptor properties of two flexible covalent cages is reported. These receptors consist of two zinc(II) porphyrins connected by four linkers of two different sizes, each incorporating two 1,2,3‐triazolyl ligands. Silver(I) ions act as effectors, responsible for an on/off encapsulation mechanism of neutral guest molecules. Binding silver(I) ions to the triazoles opens the cages and triggers the coordination of pyrazine or the encapsulation of N,N′‐dibutyl‐1,4,5,8‐naphthalene diimide. The X‐ray structure of the silver(I)‐complexed receptor with short connectors is reported, revealing the hollow structure with a cavity well‐defined by two eclipsed porphyrins. Rath…
A Bis‐Acridinium Macrocycle as Multi‐Responsive Receptor and Selective Phase‐Transfer Agent of Perylene
A bis‐acridinium cyclophane incorporating switchable acridinium moieties linked by a 3,5‐dipyridylanisole spacer was studied as a multi‐responsive host for polycyclic aromatic hydrocarbon guests. Complexation of perylene was proven to be the most effective and was characterized in particular by a charge transfer band as signal output. Effective catch and release of the guest was triggered by both chemical (proton/hydroxide) and redox stimuli. Moreover, the dicationic host was also easily switched between organic and perfluorocarbon phases for application related to the enrichment of perylene from a mixture of polycyclic aromatic hydrocarbons. peerReviewed
Synthesis of a Linear Assembly Consisting of a Central Ru(Phen)32+ Derivative and Two Peripheral Porphyrins
A ruthenium(II) precursor complex containing a bis-phenanthroline ligand, leading to a controlled helical structure around the metal centre, and a third phenanthroline-type ligand has been prepared. The spatial arrangement of the system is such that two chemical groups are disposed trans to one another on an axis running through the Ru centre. By appropriate functional group transformation, these two groups can be attached to monosubstituted zinc(II) porphyrins (PZn) to afford a linear array consisting of a central ruthenium(II) complex and two peripheral PZn motifs. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
CCDC 1844318: Experimental Crystal Structure Determination
Related Article: Ryan Djemili, Lucas Kocher, Stéphanie Durot, Anssi Peuronen, Kari Rissanen, Valérie Heitz|2018|Chem.-Eur.J.|||doi:10.1002/chem.201805498
CCDC 2003776: Experimental Crystal Structure Determination
Related Article: Johnny Hu, Jas S. Ward, Alain Chaumont, Kari Rissanen, Jean-Marc Vincent, Valérie Heitz, Henri-Pierre Jacquot de Rouville|2020|Angew.Chem.,Int.Ed.|59|23206|doi:10.1002/anie.202009212
CCDC 1844317: Experimental Crystal Structure Determination
Related Article: Ryan Djemili, Lucas Kocher, Stéphanie Durot, Anssi Peuronen, Kari Rissanen, Valérie Heitz|2018|Chem.-Eur.J.|||doi:10.1002/chem.201805498