Controlling Photoreactions Through Noncovalent Interactions Within Zeolite Nanocages

Abstract

Drawing inspiration from nature, chemists have employed confi nement as a tool to achieve selectivity in chemical reactions. 1 Confi ning reactants has the power to drive chemical reactions with astonishing precision as seen in the remarkable selectivities exhibited by enzymes in chemical processes, the phenomenon of photosynthesis, and so on. Within a confi ned environment, 2 the familiar electronic and steric effects of solution chemistry are replaced by structural and topological factors that frequently result in products that display a level of selectivity or specifi city that has hitherto been unobtainable in solution. Upon confi nement, inherent reactivity of confi ned guests often becomes of secondary importance compared with features such as symmetry, geometric considerations, and noncovalent interactions that develop within the confi ned environments. This review will highlight the confi nement effect offered by zeolite Y supercages, 3,4 the noncovalent interaction (viz., cation -π and cationcarbonyl interactions) 5,6 that develops upon inclusion of substrates within faujasite zeolite X/Y supercages, and the effect of such interactions in photophysical and photochemical processes). 7,8 ZEOLITE Y SUPERCAGES: NANOCAVITY THAT OFFERS NONCOVALENT INTERACTIONSZeolites 3 are inorganic crystalline aluminosilicate microporous materials (particle size ranges 0.1 -10 μ m, 40 naturally occurring and more than 100 synthetic 389Supramolecular Photochemistry: Controlling Photochemical Processes, First Edition. Edited by V. Ramamurthy and Yoshihisa Inoue.

Supramolecular catalysis. Part 2: artificial enzyme mimics

“…238 Photochemical reactions are a particular class of reactions in 100 which proximity between the reacting groups and stabilisation of a given conformation in the ground and excited states are important parameters which influence the reaction pathway. 239,240 Activity and selectivity are greatly affected by the reaction media: the solid state, [240][241][242][243][244][245][246] within a liquid crystal, 247 presence of a 105 stoichiometric [248][249][250][251][252][253][254][255][256][257][258][259] or a catalytic [260][261][262] amount of a hydrogen bond template, 263,264 zeolites, 265 dendrimers, micelles, and any other covalent or non-covalent hosts. 239,240 Cyclodextrin, [266][267][268][269][270][271][272][273][274][275][276][277][278] cucurbituril, 276,[279][280][2...…”

Modulating the reactivity of chromone and its derivatives through encapsulation in a self-assembled phenylethynylene bis-urea host

“…Inspired by nature's exquisite control over reactivity within the defined spaces of enzyme active sites, chemists have designed and investigated many molecular and supramolecular hosts as well as examined the use of porous materials to facilitate the reaction of encapsulated guests [1][2][3][4][5][6][7]. These 'nanoreactors' provide confined environments to induce selectivity, modulate the reaction pathway, and potentially catalyze the reaction [8].…”

Theoretical FRET Efficiency of an Antenna Material Containing Natural Dyes and Zeolite L

“…Physically distinct contributions dominate the IE of two monomers in the vacuum: electrostatic, exchange, induction, and dispersion energies. The supramolecular approach is the most straightforward way for calculating IEs, and it takes into account exclusively the difference between the energy of the dimers and all of their isolated energies. , normalD normalY IE cp = normalD normalY normalE ( DA ) − normalD normalE ( DA ) − normalA normalE ( DA ) where DY IE cp is the counterpoised (cp) IE of the isolated dimer, DY E (DA) is the energy of the isolated dimer, D E (DA) is the energy of the donor calculated in the isolated dimer DA, and A E (DA) is the energy of the acceptor calculated in the isolated dimer DA.…”

“…On the other hand, the calculation of IEs of complete composites had to take into account the resulting deformation energies of monomers, derived from the interplay between flexible molecules and the host system . Thus, eqs – lead to obtaining the desired IEs in the context of the supramolecular approach C IE cp = C normalE ( DN ) − D Y E false( DN false) − N normalE ( DN ) − ( Z δ E + B δ E ) where C IE cp is the counterpoised-corrected IE of the complete composite.…”

“…Physically distinct contributions dominate the IE of two monomers in the vacuum: electrostatic, exchange, induction, and dispersion energies. The supramolecular approach is the most straightforward way for calculating IEs, and it takes into account exclusively the difference between the energy of the dimers and all of their isolated energies. , where DY IE cp is the counterpoised (cp) IE of the isolated dimer, DY E (DA) is the energy of the isolated dimer, D E (DA) is the energy of the donor calculated in the isolated dimer DA, and A E (DA) is the energy of the acceptor calculated in the isolated dimer DA.…”