Soluble Synthetic Multiporphyrin Arrays. 3. Static Spectroscopic and Electrochemical Probes of Electronic Communication

摘要: A comprehensive electrochemical (cyclic and square-wave voltammetry, coulometry) static spectroscopic (absorption, resonance Raman (RR), electron paramagnetic (EPR)) study is reported for a series of dimeric trimeric porphyrin-based arrays. All the arrays consist tetraarylporphyrins linked via ethyne groups at p-positions aryl rings. The complexes investigated include zinc-free base bis-zinc dimers which contain varying degees torsional constraint between porphyrin rings group linker, linear right-angle trimers in two zinc porphyrins are bridged by either or free porphyrin. studies were performed on singly multiply oxidized as well natural species. spectral properties indicate that electronic communication macrocycles relatively weak ground excited states. This through-bond, rather than through-space, mediated diarylethyne linker. EPR spectra exhibit complex temperature-dependent signatures reflect hole/electron hopping and/or spin exchange interactions state. Exchange significant (probably 1000 MHz pr greater) both liquid frozen solutions and, certain cases,more » enhanced upon solvent freezing. 45 refs., 12 figs., 3 tabs.« less