Syntheses, Spectroelectrochemical Studies, and Molecular and Electronic Structures of Ferrocenyl Ene-diynes

Abstract

of [3a´] + , [3b´] + and [3d´] +. Table of crystallographic refinement details. This material is available free of charge via the Internet at http://pubs.acs.org.

Quantum-chemical insights into mixed-valence systems: within and beyond the Robin–Day scheme

“…120 These validation studies, which required the adequate inclusion of solvent effects, will be discussed in some more detail in the following sections, as will be the extension to MV transition-metal complexes. [158][159][160] Overall, the BLYP35/ COSMO based protocol and its variations using either suitable alternative functionals or alternative solvent models have turned out to provide an unprecedentedly detailed bracketing of localisation vs. delocalisation close to the borderline in a wide variety of MV systems.…”

Mixed‐Valence Ruthenium Complexes Rotating through a Conformational Robin–Day Continuum

“…[18][19][20][21][22] Still more recently, it has been extended to applications in the modeling of ET processes in transition-metal MV systems. [17,23] However, regardless of the computational methodology employed, any interpretation of quantum-chemical results based on a single, static, lowest-energy molecular structure will not accurately model systems in which molecular dynamics play an important role on the optoelectronic properties of a molecule. These points are illustrated further below.…”

“…[17] The identification of these conformational factors prompt reconsideration of other ligand-bridged bimetallic mixedvalence complexes [M-bridge-M] + in which d-π-d overlap along the molecular backbone can be anticipated to be strongly dependent on the relative orientation of the constituent fragments. A quantum-chemical methodology that gives a faithful description of localization/delocalization (see below), [17][18][19][20][21][22][23] has been used here to reconsider the description of three formally mixed-valence bimetallic ruthenium complexes for which a wealth of experimental data has been accumulated (Chart 1 [2] + both contain the 1,4-diethynylbenzene (µ-C≡CC 6 H 4 C≡C) bridge but differ in the composition of the supporting ligands, and in both cases, conflicting evidence exists regarding the MV classification. [24,25] For comparison purposes, the classical coordination complex, the Creutz-Taube ion, [6,7,26] [3]…”

Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp*(dppe)M–C≡C–1,4-(C6H4) Complexes

“…[25][26][27][28] Indeed, in recent times there has been a resurgence of interest in mixed-valence models of intramolecular charge-transfer processes, with the development of theoretical descriptions and spectroscopic analysis of the charge-transfer event 29 to the development of novel optoelectronic materials and the design of molecular electronic components. 30 Some of the present authors have explored aspects, including mixed-valence characteristics, of cross-conjugated 1,1-bis(alkynyl)-2-ferrocenylethene derivatives (A), 31 including 1,1-bis(ferocenylalkynyl)-2-ferrocenylethene (B) 32 and tetrakis(ferrocenylethynyl)ethene (C) 33 (Chart 1). However, efforts to incorporate the half-sandwich building blocks M(PP)Cp', which have been so successful in exploring other aspects of organometallic mixed-valency when linked through linearly conjugated all-carbon and carbon-rich bridging ligands, [34][35][36][37][38][39][40]…”