Assembly and Stepwise Oxidation of Interpenetrated Coordination Cages Based on Phenothiazine

Abstract

A breath of fresh air is sufficient for the eightfold S-monooxygenation of an interpenetrated double cage based on eight phenothiazine ligands and four square-planar-coordinated Pd(II) cations. Besides these two cages, which were both characterized by X-ray crystallography, an eightfold S-dioxygenated double-cage was obtained under harsher oxidation conditions.

Donor‐Site‐Directed Rational Assembly of Heteroleptic cis‐[Pd2L2L′2] Coordination Cages from Picolyl Ligands

“…Since the Pd‐mediated self‐assembly of phenothiazine‐derived banana‐shaped ligands is well described, we chose to investigate the self‐sorting of picolyl ligands P i and P o with the already established ligands A i and A o . Homoleptic assemblies from P i and P o were found to be of analogous composition to that observed for the acridone ligands.…”

Interpenetrated Cage Structures

“…The radical cations generated from the free ligands reacted more slowly with water as compared to the eightfold radical‐cationic double‐cage. The dense packing in the supramolecular assembly is assumed to enhance the probability of the disproportionation reaction within the cage framework compared to the bimolecular process that is proposed for the free ligands . Recently, the electron‐rich phenothiazine ligands 53 were combined with electron‐deficient anthraquinone ligands (not shown) in mixed‐ligand double‐cages that show light‐induced charge separation from donors to acceptors upon photoexcitation…”

Solution‐Phase Dynamic Assembly of Permanently Interlocked Aryleneethynylene Cages through Alkyne Metathesis

“…Later, metalcoordination-based interlocked cages with various topologies were reported by Kuroda et al, [10] Hardie et al, [11] and Clever and co-workers. [12,13] Purely organic interlocked cages are even rarer.The first example of such acomplex was reported by Cooper et al through dynamic imine reactions, [14] with as ubsequent example by Mastalerz and co-workers employing boronic acid condensation reactions. [15] In both cases, ak inetically interrupted thermodynamic approach was employed, in which the interlocked species were precipitated as crystals and irreversibly removed from the dynamic system.…”

“…Thec oordination or covalent interlocked cages reported so far are mostly assembled in multiply interlocked conformations (all the windows are penetrated), achieving maximum p-p stacking or hydrogenbonding interactions between the two interlocked species. [9][10][11][12][13][14][15] Computational calculations on the energy-minimized structures of conformer Ia nd II show that triply-interlocked conformer Ii s2 3kcal mol À1 more stable than conformer II. Conformer Iisstabilized by the p-p interactions between all three lateral arms and two panels of each trigonal prismatic cage,which likely represents the conformation of 2a/2b.Our extensive crystallization trials with 2b failed to produce single-crystals of sufficient quality for X-ray diffraction analysis.…”