p Matching Enables Quantum Proton Delocalization in Acid-1-Methylimidazole Binary Mixtures.

Short hydrogen bonds (SHBs), characterized by donor-acceptor heteroatom separations below 2.7 Å, are prevalent in condensed-phase systems. Recently, we identified SHBs in nonaqueous binary mixtures of acetic acid and 1-methylimidazole (MIm), where electronic and nuclear quantum effects facilitate extensive proton delocalization.

Assembly of water-soluble, dynamic, covalent container molecules and their application in the room-temperature stabilization of protoadamantene.

The thermodynamically controlled reactions of water-soluble tetraformylcavitand 2 with two equivalents of H(2)N(CH(2))(n) NH(2) (n=2-4) in the presence of a suitable templating guest give hemicarceplexes 1 a-c⋅guest, the yield of which depends on the match between size and shape of the guest and that of the inner phase. These hemicarceplexes are dynamic and dissociate upon addition of acid and reform upon basification. In water, they exchange guests through temporary hydrolysis of imine bonds.

Transient innermolecular carbene-hemicarcerand complex of fluorophenylcarbene.

Laser flash photolysis of fluorophenyldiazirine incarcerated in hemicarcerand 2 affords incarcerated fluorophenylcarbene [2⊙3], which forms a metastable, innermolecular π-complex with aryl moieties of 2. This carbene complex can be observed spectroscopically. Extensive computational studies provide insights into the structure, spectroscopy, energetics, and kinetics of the 2⊙3 carbene complex.

Rational design of a nanometre-sized covalent octahedron.

The thermodynamically controlled reaction of six tetraformylcavitands with twelve rigid, linear diamines yields quantitatively polyimine octahedrons with diameters of up to 5 nm. The cavitands are optimized to match the ideal geometry of a 60° tetratopic vertex unit and are connected along the octahedron edges with the diamines through 24 newly formed imine bonds.

Multicomponent assembly of cavitand-based polyacylhydrazone nanocapsules.

The thermodynamically controlled syntheses of different di-, tetra-, and hexacavitand polyacylhydrazone nanocapsules are reported. [2+4]-, [4+8]-, and [6+12]-nanocapsules assemble upon reacting a tetraformyl cavitand with two equivalents of isophthalic dihydrazide, or terephthalic dihydrazide in the presence of trifluoroacetic acid, whereby the building blocks are linked together through 8, 16, or 24 newly formed acylhydrazone bonds. Futhermore, the reaction of the tetraformylcavitands with different trigonal planar trihydrazides, simultaneously leads to the formation of [2+4]- and [6+8]-nanocapsules in varying ratios that depend on the cavitand to trihydrazide ratio and the nature of the cavitand and trihydrazide building blocks.