Electron‐Transfer Studies of trans‐Platinum Bis(acetylide) Complexes

Abstract

The complexes trans- [Pt(CϵCFc) 2

(Spectro)electrochemical Properties of Anthracene Containing Triarylamine Platinum(II) Acetylides

“…25°C) in the presence of 2 mol-% copper iodide, a cis-trans isomerization furnishes mono-acetylide complex trans-4 ([Pt{2}Cl(PPh 3 ) 2 ]. [17,24,37] The use of 2 mol-% CuI during the acetylation reaction led to a halogen exchange. In complex trans-4 the trans-effect of the acetylene ligand strengthens the bond to the remaining chlorido ligand [38,39] and hence, the ligand exchange reaction with the second acetylene does not take place, even at elevated temperatures (up to 60°C).…”

“…[19,20] These charge transfer events can be triggered electrochemically by reduction or oxidation events at the ligand [21,22] as well as photochemically in form of metal-to-ligand-(MLCT) [15,23] or ligand-to-metal charge transfer (LMCT) excitations. [24] In this respect, the combination of platinum acetylide complexes with redox active groups allows to switch the optical properties of the material electrochemically by adjusting the oxidation state of the respective ligand. Triarylamines, in this context, are an exceptionally favorable choice as redox active units, since they combine well behaved redox chemistry [25] with polyelectrochromic behavior.…”

“…In particular, platinum (II) acetylides have shown to exhibit second‐ and third‐order non‐linear optical properties, [17] while simultaneously featuring electrochemical properties [18] that allow the ligand to either donate or withdraw electron density from the Pt(II) center [19,20] . These charge transfer events can be triggered electrochemically by reduction or oxidation events at the ligand [21,22] as well as photochemically in form of metal‐to‐ligand‐ (MLCT) [15,23] or ligand‐to‐metal charge transfer (LMCT) excitations [24] . In this respect, the combination of platinum acetylide complexes with redox active groups allows to switch the optical properties of the material electrochemically by adjusting the oxidation state of the respective ligand.…”

RuII and RuIII Chloronitrile Complexes: Synthesis, Reaction Chemistry, Solid State Structure, and (Spectro)Electrochemical Behavior

“…[36] In contrast to smaller counterions such as [PF 6 ]or [Cl] -, the weakly coordinating [B(C 6 F 5 ) 4 ]is known to stabilize highly charged species in solution and to minimize ion pairing effects. [36,50,[64][65][66] The CV measurements were performed at 25°C (4a,b, 7b, 8), -30°C (6) or -72°C (4b) as noted in Table 3 and the Figure legends. All potentials are referenced to the FcH/FcH + (FcH = Fe(η 5 -C 5 H 5 ) 2 ) redox couple as an internal standard.…”

“…In order to analyze the in situ electrochemical behavior of 4a,b, spectroelectro-IR measurements were carried out using an OTTLE [51] (Optically Transparent Thin-Layer Electrochemical) cell with CaF 2 windows, dichloromethane solutions of the analyte and Fc*-containing mixtures (5.0 mmol•L -1 ), containing [NBu 4 ][B(C 6 F 5 ) 4 ] (0.1 mol•L -1 ) as supporting electrolyte. [51,66] During the measurements, the applied cell potential was increased stepwise (step width: 25 mV, 50 mV or 100 mV).…”