Synthesis, Electronic Properties, and Self-Assembly on Au{111} of Thiolated Phenylethynyl Phenothiazines

Abstract

Thiolated phenylethynyl phenothiazines can be regarded as redox-active "alligator clips". They are readily synthesized from ethynyl phenothiazines and show intense blue-green luminescence upon ultraviolet (UV) excitation. Cyclic voltammetry reveals reversible oxidation, also after the chemisorption of in situ liberated thiols on gold electrodes. The chemisorption on Au{111} was studied by ellipsometry, contact angle measurements, X-ray photoelectron spectroscopy, and infrared reflection absorption spectroscopy, and the obtained data support the formation of self-assembled monolayers, depending on the structure of the substrates. These findings classify them as promising candidates for molecular wires switchable by redox manipulation.

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

“…Based upon thorough surface analysis of the previously studied thiolated phenylethynyl phenothiazines chemisorbed on Au{111} by ellipsometry, contact angle measurements, X-ray photoelectron spectroscopy, and infrared reflection absorption spectroscopy (IRRAS) [ 39 ], we applied ellipsometry in combination with molecular modeling at the force field and DFT levels of theory for the characterization of SAMs of in situ liberated (oligo)phenothiazinyl thiols on Au{111}. The ability of the molecules to form SAMs was investigated by solution adsorption of different systems onto gold films of 100 nm thickness thermally evaporated onto Si wafers using 10 nm of Ti as adhesion promoter.…”

“…Furthermore, the transformation of phenothiazines into stable planar radical cations with excellent delocalization [ 37 ] qualifies them as excellent models for switchable conductive or semiconductive molecular wires. Encouraged by successful electrode modifications with conjugated thiolated anilines [ 38 ] and SAM formation of thiolated phenylethynyl phenothiazines [ 39 ], and in continuation of our investigations directed towards the synthesis and study of (oligo)phenothiazine-based functional π-systems [ 40 – 46 ], we have now focused our attention on thiolated phenothiazines and (oligo)phenothiazines as “alligator-clips”. Here, we report the synthesis of phenothiazines and their oligomers bearing “alligator-clips” and their electronic properties as studied by cyclic voltammetry (CV), spectroscopic and spectrometric methods.…”

Oxidative Coupling of Methane: Opportunities for Microkinetic Model‐Assisted Process Implementations

“…Such anchor groups are often used for thin‐film coating of and efficient charge transfer to metal oxides in hybrid photovoltaic concepts 11. 31 Plus, the hole injection barrier Φ Bh of 3 is, at 0.7 eV, very small. As the successful preparation of thin films under ambient conditions shows, DTPTs are easy to process on an industrial scale for applications in organic electronics.…”

Phenothiazine Based Donor–Acceptor Compounds with Solid‐State Emission in the Yellow to NIR Region and Their Highly Selective and Sensitive Detection of Cyanide Ion in ppb Level

“…This detrimental phenomenonp revents these fluorophores from many real world applications, which primarily requireh ighe mission in the solid state. [12][13][14][15]18] EDOT,o nt he other hand is well knownf or its high molar absorptivity and bathochromic shift of absorption when p-linked to other chromophores. [12] With this strategyi nm ind, we have designed and synthesized four new fluorophores based on phenothiazine (PTz) and ethylenedioxythiophene (EDOT) (Scheme1).…”