Bistability of valence tautomeric donor−acceptor dyads formed by covalently linking a ferrocene-based electron- donor and the perchlorotriphenylmethyl radical, as the electron-acceptor, is tuned via a chemical modiﬁcation of the ferrocene group. Speciﬁcally, the methylation of the ferrocene unit increases the strength of the donor group stabilizing the zwitterionic state in polar solvents and leading to an intriguing coexistence of neutral and zwitterionic species in solvents of intermediate polarity. Bistability in the crystalline phase is demonstrated by temperature dependent Mössbauer spectra. This complex and interesting behavior is quantitatively rationalized in the framework of a bottom-up modeling strategy. Optical spectra in solution are ﬁrst analyzed to extract and parametrize an eﬀective two-state molecular model, which is then adopted to rationalize the observed bistability in the solid state as due to cooperative electrostatic interchromophore interactions.
|Titolo:||Bistability of Fc-PTM-Based Dyads: The Role of the Donor Strength|
|Autori:||J. Guasch; L. Grisanti; S. Jung; D. Morales; G. D’Avino; M. Souto; X. Fontrodona; A. Painelli; F. Renz; I. Ratera; J. Veciana|
|Rivista:||CHEMISTRY OF MATERIALS|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/cm400147p|
|Appare nelle tipologie:||1.1 Journal article|