Electron transport through a (terpyridine)ruthenium metallo-surfactant containing a redox-active aminocatechol derivative

Abstract

Aiming to develop a new class of metallosurfactants with unidirectional electron transfer properties, a (terpyridine) ruthenium complex containing a semiquinone derivative L2, namely [RuIII(Lterpy)(L2)Cl]PF6 (1), was synthesized and structurally characterized...

Probing the effect of nitro-substituents in the modulation of LUMO energies for directional electron transport through 4d6ruthenium(ii)-based metallosurfactants

“…We propose that electron transport takes place via the phen-based LUMO orbital whose energy is modulated by the NO 2 substituent, and now comparable to the Fermi levels of the electrode. This situation is similar to that of our recently reported [Ru III (L terpy )(SQ)Cl]PF 6 system, 17 in which a low lying LUMO primarily associated with the semiquinone ligand SQ, can partake in directional electron transport. This behavior is distinctive from the temperature-dependent Kondo effect observed for electron transport in the [Co II (S-terpy) 2 ] species studied by Park et al 3 and from the configuration-dependent electron transport described by van der Zant et al 5 for a [Mn II (S-terpy) 2 ].…”

“…1e,16 Our groups recently demonstrated directional transport in a heteroleptic LS 4d 5 [Ru III (C 18 OPh-terpy)(SQ)Cl]PF 6 metallosurfactant in which C 18 -Ph-terpy is the amphiphilic ligand 4′-(4octadecyloxyphenyl)-2,2′:6′,2″-terpyridine and SQ is the deprotonated aminosemiquinone form of the ligand 2,4-di-tertbutyl-6-( phenylamino)phenol ligand. 17 The asymmetric I/V profile of this species lies in distinct contrast with the symmetric response obtained by the other [Ru(terpy) 2 ] species and the electronic and redox results point out to a low lying SQbased LUMO near the Fermi level of the electrodes as respon-sible for electron transport. These results allowed us to hypothesize that heavily distorted O h species with distinct N, O, and Cl donors enable transport through empty and heavily mixed molecular orbitals with predominant ligand character.…”

Influence of Peripheral and Ancillary Changes on the Electron Transport of HS3d5 FeIII Metallosurfactants – Substituents, Chain Length, Subphase Polarity, and Junction Electrodes

“…This observation confirms our hypothesis that extending the alkoxy chain would lead to improved amphiphilic balance and enhance film formation and transfer onto the solid substrate, ultimately leading to comparable electron transport between 2 and 3 . The observed lower currents for 2 are tentatively attributed to an increased tunneling distance. ,− A similar behavior was reported for cobaltocene-based species. , The match between the Fermi and SOMO energy levels in metallosurfactants 1 and 2 indicates better feasibility of unidirectional electron transport than that of t -Bu-substituted 3 .…”

Coordination-driven opto-electroactive molecular thin films in electronic circuits

“…Metal-polypyridyl complexes have been well investigated due to their rich coordination chemistry, excellent optical properties, and reversible electrochemical charge transfer properties. [55][56][57][58][59][60] In this work, we chose the bis-terpyridyl ligand (bis-tpy) that shows the structural advantages of having a 'back-to-back' metal ion receptor and unidirectionality, forming a chelated ring, providing extra stability to the in situ formed on-surface coordination complexes. 4 0 -Aminophenyl terpyridine (4 0 -NH 2tpy, Fig.…”