Testing the Conjugative Properties of Benzodithiophene and Benzotrithiophene in Charge Transfer Multi(ferrocenyl) Systems

Abstract

The charge transfer properties of the mono-, di-, and tricationic derivatives of bis(ferrocenyl)benzodithiophene and tris(ferrocenyl)benzotrithiophene were investigated. The cations were generated by chemical oxidation using ferrocenium(BF4) and acetylferrocenium(BF4) as the oxidative agents, and monitored in the visible and NIR regions. By changing the supporting electrolyte from [nBu4N][PF6] to [nBu4][B(C6F5)4] we were able to selectively generate the monocationic species of bis and triferrocenyl complexes. The redox and optical properties of the cationic derivatives were rationalized by an in-depth electrochemical and optical study. The comparison with the results previously obtained for the structurally related bis(ferrocenyl)-s-indacene and tris(ferrocenyl)-trindene allowed for the evaluation of the huge influence of thiolation on the metal-metal electronic coupling. RESULTS AND DISCUSSION Electrochemistry. Oxidative cyclic voltammetry (CV) of 1 and 2 recorded under argon in CH2Cl2/0.1 M nBu4NB(C6F5)4, (Figures 1a,c). Large waves with oxidation potential maximum at 0.27 (1) and 0.24 V (2) are present.

The core of the matter – arene substitution determines the coordination and catalytic behaviour of tris(1-phosphanyl-1′-ferrocenylene)arene gold(i) complexes

“…36 As the groups of Lang and Santi have extensively shown, the nature of the arene core is decisive for the electrochemical response of the system both in terms of redox potentials and electronic communication, that is, the existence of mixedvalent oxidised states. [21][22][23][37][38][39][40][41][42][43][44][45][46][47][48][49] In our case, 1 : 1 ligand-tometal complexes of triazine derivative 1a (Chart 2, left) showed a distinct delocalised coinage metal-π(C 3 N 3 ) interaction, 50 while 1 : 3 ligand-to-gold complexes of 1a-c (Chart 2, right) demonstrated how the electron density of the respective core determined the electrochemical response both with respect to redox potential and reversibility. Furthermore, the arene cores were also found to impact the catalytic activity of these trinuclear gold(I) complexes in the ring-closing isomerisation of N-(2-propyn-1-yl)benzamide (2) to 5-methylene-2-phenyl-4,5dihydrooxazole (3a).…”

Unexpected Formation of a Silicon-Centered Spirocyclic Oligosiloxane Bearing Eight Pendant Ferrocene Units

“…On the other hand, over the past few decades, the design of multiferrocenyl macromolecular structures has evolved to be one the most appealing subjects within various areas 2 of 10 of research, including organometallic and supramolecular chemistries, electrochemistry, catalysis, biomolecules, sensors, and molecular recognition [14][15][16][17][18][19][20].…”

Dendritic Groups Substituted Kekulé‐Benzene‐Bridged Bis(triarylamine) Mixed‐valence Systems: Syntheses, Characterization and Electronic Coupling Properties

“…Mixed‐valence (MV) chemistry based on organic or inorganic model compounds have been applied widely in exploring the intramolecular electron transfer (ET) process . Numerous model systems were constructed by conjugated cores linked to organic/inorganic redox‐active centers, which exhibit unique photophysical properties and potential applications in molecular devices . Suitable redox‐active termini with desirable reversibility and stability are normally used to efficiently evaluate the ET capability of bridge π‐conjugative cores …”

“…[1][2][3][4] Numerous model systems were constructed by conjugated cores linked to organic/inorganic redox-active centers, which exhibit unique photophysical properties and potential applications in molecular devices. [5][6][7][8][9][10][11][12] Suitable redox-active termini with desirable reversibility and stability are normally used to efficiently evaluate the ET capability of bridge π-conjugative cores. [1,2] Given their novel redox properties, triarylamine (TPA) derivatives have gained particular attention from scientists who focus on organic optoelectronic devices, such as organic lightemitting diodes [13][14] and organic field-effect transistors, [15][16] dye-sensitized solar cells, [17][18] and near-infrared (NIR) electrochromic materials, [19] especially as redox-active termini building up the MV systems.…”