Control of dominant conduction orbitals by peripheral substituents in paddle-wheel diruthenium alkynyl molecular junctions

Abstract

Control of charge carriers that transport through the molecular junctions is essential for thermoelectric materials. In general, the charge carrier depends on the dominant conduction orbitals and is dominantly determined...

Metal Complex Molecular Junctions as Thermoelectric Devices

“…[36] Such metal acetylide complexes have been reported to exhibit unique and high conductance. [24,31,[37][38][39][40][41][42][43] Compared to organic derivatives, ruthenium (3) and platinum acetylide junctions (4) were characterized by higher Seebeck coefficient values (7.1 and 6.1 μV/K, respectively, versus 3.7 μV/K for 1 and 4.5 μV/K for 2). The positive Seebeck coefficient for 1-4 indicated that these complexes are characterized by HOMO-dominant hole transport processes.…”

“…conducted thermoelectric measurements on ruthenium and platinum acetylide complexes and organic derivatives 1 – 4 of SMJ implementing the STM‐BJ method (Figure 6). [36] Such metal acetylide complexes have been reported to exhibit unique and high conductance [24,31,37–43] . Compared to organic derivatives, ruthenium ( 3 ) and platinum acetylide junctions ( 4 ) were characterized by higher Seebeck coefficient values (7.1 and 6.1 μV/K, respectively, versus 3.7 μV/K for 1 and 4.5 μV/K for 2 ).…”

Bisaryl and Bisalkynyl Diruthenium (III,III) Compounds Based on an Electron-Deficient Building Block

“…The chemical robustness of Ru 2 ( ap ) 4 -based compounds also allows for iterative on-complex Cadiot–Chodkiewicz coupling, yielding extended oligo-yne compounds Ru 2 ( ap ) 4 (C 2 k SiR 3 ) with k up to 5 . The ability to mediate charge transfer has been exploited in the construct of prototypical molecular wires and devices. − Recent work by the laboratory of Akita further illustrates the unique conductivity characteristics afforded by the tunable valence orbital distribution of Ru 2 alkynyls near the Fermi level of the nanojunction . In addition to Ru 2 ( ap ) 4 -based organometallics, assemblies based on Ru 2 ( ap ) 4 (CN) have been utilized for studying spin-coupling and metal–metal charge-transfer transitions by the laboratory of Sheng in recent years. − Kadish and Van Caemelbecke investigated the formation of water-soluble Ru 2 (OAc) 3 (L)Cl with L as a variety of fluorinated ap ligands …”

“…26−28 Recent work by the laboratory of Akita further illustrates the unique conductivity characteristics afforded by the tunable valence orbital distribution of Ru 2 alkynyls near the Fermi level of the nanojunction. 29 In addition to Ru 2 (ap) 4 -based organometallics, assemblies based on Ru 2 (ap) 4 (CN) have been utilized for studying spin-coupling and metal−metal chargetransfer transitions by the laboratory of Sheng in recent years. 30−32 Kadish and Van Caemelbecke investigated the formation of water-soluble Ru 2 (OAc) 3 (L)Cl with L as a variety of fluorinated ap ligands.…”

Phenylene as an efficient mediator for intermetallic electronic coupling

“…14,15 Facile charge delocalization across the bridging oligoyn-diyl (C 2n ) has been demonstrated in [Ru 2 (ap) 4 ] 2 (m-C 2n ) type compounds (ap = 2-anilinopyridinate) through Vis-NIR spectroelectrochemical (SEC) experiments in bulk solutions. 16,17 The rich redox characteristics of Ru 2 compounds further enable a broad range of applications as wires in nanojunctions, 18,19 spin-chains, 20 and catalytic activation of small molecules. [21][22][23] More recently, Ru 2 (ap) 4 (Ar) type compounds (Ar = aryl) were prepared, 24 and their capacity in binding small linear ligands such as CO, CN À and C 2 H À at the axial site trans-to Ar was demonstrated.…”