A coordination chemistry-based approach for the synthesis of stimulant-responsive supramolecular cofacial porphyrin complexes.

摘要

This dissertation focuses on the utilization of two coordination chemistry-based synthetic approaches, which provide the ability to rapidly and quantitatively assemble sophisticated supramolecular cofacial porphyrin complexes. Significantly, by adopting a coordination chemistry-based approach, the porphyrin-porphyrin interactions can be regulated in situ via the addition or removal of chemical effector molecules.;In Chapter 2, the synthesis of the 1st generation thioether- and ether hemilabile porphyrin ligands is presented in addition to the synthesis of the corresponding RhI and CuI macrocyclic complexes using these ligands via the Weak-Link Approach (WLA). Owing to the ability for the thioether-based hemilabile ligand to form condensed and open structures, the allosteric catalytic activity has been studied using a proof-of-concept acyl transfer reaction between 1-acetylimidazole and a series of N-pyridylcarbinol (where N = 2-, 3-, or 4-) substrates. These complexes not only catalyze this acyl transfer reaction allosterically, but also are capable of discriminating substrates based upon the regiosubstitution of the pyridylcarbinol substrates.;In Chapter 3, a halide-induced ligand rearrangement reaction (HILR) is utilized to prepare dissymmetric heteroligated cofacial porphyrin macrocyclic complexes. Significantly, since the HILR relies upon the use of both a thioether- and ether-based hemilabile ligand, it provides a highly convergent and convenient platform for the synthesis of cofacial porphyrin complexes where the metal bound within each porphyrin chromophore is unique. Additionally, since the coordination environment about each RhI structural site consists of both ether- and thioether donor atoms, the porphyrin-porphyrin interactions can be selectively modulated in situ via the addition or removal of small molecule effectors.;In Chapter 4, the synthesis of new 2nd generation ether- and thioether-based porphyrin precursors is presented. These 2nd generation porphyrin precursors were used for the preparation of new hemilabile ether- and thioether porphyrin tweezer ligands, which were subsequently used to prepare heteroligated dissymmetric cofacial porphyrin tweezer complexes. The increased solubility of these porphyrin tweezer complexes compared to the macrocyclic analogues discussed in chapter 3 enables these complexes to undergo small molecule reactions reversibly in situ without precipitation from solution.;In Chapter 5, the synthesis of porphyrin-based triple-decker complexes is achieved through utilization of the HILR. The complexes have been targeted using the hemilabile tweezer ligands described in chapter 4 and new 2 nd generation macrocycle ligands, which are presented in this chapter. Remarkably, the same synthetic approach that was developed and utilized in chapters 3 and 4 for the heteroligated macrocyclic- and tweezer porphyrin complexes can be easily extended to prepare cofacial triple-decker complexes in quantitative yield.