43 research outputs found
Designing Conducting Polymers Using Bioinspired Ant Algorithms
Ant algorithms are inspired in real ants and the main idea is to create
virtual ants that travel into the space of possible solution depositing virtual
pheromone proportional to how good a specific solution is. This creates a
autocatalytic (positive feedback) process that can be used to generate
automatic solutions to very difficult problems. In the present work we show
that these algorithms can be used coupled to tight-binding hamiltonians to
design conducting polymers with pre-specified properties. The methodology is
completely general and can be used for a large number of optimization problems
in materials science
Panchromatic light harvesting and stabilizing charge-separated states in corrole–phthalocyanine conjugates through coordinating a subphthalocyanine
Owing to the electron-donating and -accepting nature of corroles (Corr) and phthalocyanines (Pc), respectively, we designed and developed two novel covalently linked Corr-Pc conjugates. The synthetic route allows the preparation of the target conjugates in satisfying yields. Comprehensive steady-state absorption, fluorescence, and electrochemical assays enabled insights into energy and electron-transfer processes upon photoexcitation. Coordinating a pyridine-appended subphthalocyanine (SubPc) to the Pc of the conjugate sets up the ways and means to realize the first example of an array composed by three different porphyrinoids, which drives a cascade of energy and charge-transfer processes. Importantly, the SubPc assists in stabilizing the charge-separated state, that is, one-electron oxidized Corr and the one electron-reduced Pc, upon photoexcitation by means of a reductive charge transfer to the SubPc. To the best of our knowledge, this is the first case of an intramolecular oxidation of a Corr within electron-donor–acceptor conjugates by means of just photoexcitation. Moreover, the combination of Corr, Pc, and SubPc guarantees panchromatic absorption across the visible range of the solar spectrum, with the SubPc covering the „green gap“ that usually affects porphyrinoids