Electron‐Transfer Kinetics in Polymetallic Carbon‐Rich Ruthenium(II) Bis(σ‐arylacetylides) Wires Connected to Gold

Abstract

International audienceMol. wires consisting of RuII bis(σ-arylacetylide) organometallics functionalized with different anchoring groups (thiol, isocyanide) connected with different bridges [O, [n.63743]CH2[n.63743], [n.63743]O[n.63743](CH2)6[n.63743]] were self-assembled onto gold surfaces. The materials were characterized through wettability, ellipsometric, IR absorption reflection, and electrochem. measurements. The dynamics of the electron transfers within the monolayers were examd. with high-speed voltammetry. Similar fast electron-transfer dynamics (104 s-1) assocd. with discrete oxidn. events (up to four distinct oxidn. states) at remarkably low potentials (≤0.7 V vs. SCE) were obsd. for all complexes. Neither the extension of the mol. wires, nor the variation in the anchoring/bridging units, led to the decrease in electron-transfer kinetics. These results highlight the potential of RuII bis(σ-arylacetylide) complexes as a charge-storage medium for processing information in multibit devices with low power consumption

Redox-driven porphyrin based systems for new luminescent molecular switches

“…Indeed, group 8 metal acetylide complexes displaying strong ligand-mediated electronic effects are attractive redox-switchable building blocks for the realization of functional materials. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] This is the direct consequence of the ligand character of the highest occupied molecular orbital (HOMO) resulting from the overlap of a metal d() and an appropriate -orbital of the carbonrich ligand. [48][49][50][51][52] In particular, with ruthenium complexes of the type [ClRu(dppe)2(-CC-Aryl)]…”

Insulated molecular wires: inhibiting orthogonal contacts in metal complex based molecular junctions

“…25,26 Of the various metal complexes that have been studied in molecular junctions, including multi-metallic strings, 27 clusters, 13,28,29 porphyrins, 30,31 and ferrocene derivatives, 32,33 compounds and complexes of the group 8 metals within bipyridyl-, [34][35][36] bis(terpyridyl)- 37 or trans-bis(alkynyl)-based 38,39,[40][41][42][43][44][45][46] structures feature prominently. In contrast, analogous wire-like trans-bis (alkynyl) platinum complexes have been little explored in molecular junctions.…”

Self-Assembled Monolayers of Redox-Active 4d–4f Heterobimetallic Complexes

“…32 Fast electron transfer kinetics were reached for both monometallic and heterobimetallic systems and k ET values were found to be close to 10 4 s -1 , as already reported for closely-related self-assembled complexes. 25,35 nm length as in our present work. 14 Unfortunately, we were not able to record any emission signal after self-assembly of 1Yb at gold surface ( Figure S12).…”

“…The thioacetate group was deprotected in situ by the addition of NH 4 OH to the SAM preparation solution prior to immersion of the gold surface. This procedure was previously used with success with our type of complexes and allows for the avoidance of the formation of a multilayer as a result of the undesirable disulfide coupling. , After extensive rinsing of the surfaces and drying under a stream of argon, static contact angle measurements were performed using the sessile drop method (Table ). We observed a change in the surface wettability when the gold surface (contact angle θ equal to 60 ± 2° for a bare clean gold surface) was covered with complexes 1 (θ = 67 ± 2°), 1Yb (θ = 76 ± 2°), and 1Eu (θ = 77 ± 4°).…”