Suit[4]ane

Abstract

Suitanes are two-component mechanically interlocked molecules in which one (torso) of the components, with several protruding limbs, is encompassed by another (suit) all-in-one component. This kind of molecular ship-in-a-bottle architecture remains a challenging one to make. Herein, we report a porphyrin-based suit[4]­ane, which is composed of a porphyrin with four protruding ligands (two phenyl groups and two bromine atoms) called the limbs that are encompassed by a tricyclic octacationic cyclophane. The suit[4]­ane can be obtained by slippage, a mechanism by which the cyclophane is able to open up two of its entrances in order to take up the porphyrin at high temperature and close them down at low temperature, locking the porphyrin inside its binding cavity. Dynamic 1H NMR spectroscopy reveals that the trapped porphyrin inside the cyclophane rocks back and forth in the suit[4]­ane about 1000 times a second.

Emergent behavior in nanoconfined molecular containers

“…The encapsulated porphyrins enjoy unprecedented chemical stabilities, e.g., their D/H exchange, protonation, and solvolysis under extremely acidic conditions are completely blocked. The superstructures of these porphyrin complexes inspired us to develop 224 a novel two-component MIM, namely, suit [4] ane, in which a porphyrin with four protruding ligands (two phenyl groups and two bromine atoms) called the limbs is encompassed by another suit-like unit, the tricyclic XCage cyclophane. The suit [4]ane was obtained by a slippage mechanism where the cyclophane is able to open up two of its entrances in order to take up the porphyrin at a high temperature and close them down at a low temperature, locking the porphyrin inside its binding cavity.…”

Whither Second-Sphere Coordination?

“…The synthesis of mechanically interlocked molecules [105][106][107][108][109][110] (MIMs) such as catenanes [111][112][113][114][115][116][117][118][119][120][121][122][123][124] rotaxanes [125][126][127][128][129][130][131][132][133][134] and suitanes [135][136][137][138][139][140][141] has become a field with intense research activity on account of the potential of such molecules to act as molecular machines. [142][143][144][145][146][147][148][149][150][151][152][153][154][155] Several effective synthetic strategies of these MIMs have been achieved, based on the template effect.…”

PCage: Fluorescent Molecular Temples for Binding Sugars in Water

“…We are interested, however, in developing − pyridinium-based receptors where the C–H bonds at the α and β positions of the pyridinium units are strongly polarized. A series of extended molecular containerswith large binding cavities, which can accommodate a wide range of substrates, including flat aromatic hydrocarbons, ,− fullerenes, , and dyes − have already been reported. The conjugated nature of these pyridinium-based receptors makes them ideal scaffolds on which to design receptors that change their fluorescence upon substrate binding.…”