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The electrochemical behavior of viologen self-assembled monolayer has been investigated with QCM, which has been known as ng order mass detector. The self-assembly process of viologen was monitored using resonant frequency (ΔF) and resonant resistance (R). The QCM measurements indicated a mass adsorption for viologen assembling on the gold surface with a frequency change of about 300, 135 Hz and its surface coverage (Γ) was calculated to be 5.02 × 10^-9 and 1.64 × 10^-9 mol/cm². A reversible redox process was also observed and analyzed with an ionic interaction at the viologen/solution interface using ΔF.

Viologen has been extensively investigated in the paper because their well-behaved electro-chemistry has led to their use in a variety of thesises, including the electron acceptor for the electric charge delivery mediation of the devices. The self-assembled monolayers of alkane derivatives with sulfur containing head groups on gold substrates have been widely examined recently, since the binding between S atoms and Au surface is strong. We could know it was formed monolayer onto quartz crystal microbalance (QCM) surface by self-assembly method from resonant frequency shift using quartz crystal analyzer (QCA). The measured frequency shift were about 408 Hz by VC₈SH. From this value, we calculated that the mass adsorbed VC₈SH were about 432 ng. The EQCM measurements revealed that anions exit and enter the viologen monolayer during reduction and oxidation, respectively. We also use the scanning tunneling microscopy (STM) for manipulating the surface on a nanometer scale to form nanostructures.

Lysine-linked viologen was prepared as a substrate for the hydrogenase. By using reduced lysine-linked viologen (LysV^+•), the hydrogenase-LysV^+• complex was formed efficiently, leading to effective hydrogen evolution compared with methyl viologen. Lysine-linked viologen as an electron carrier was applied for the photoinduced hydrogen evolution system containing hydrogenase, Tetrakis(4-carboxyphenyl)porphyrin (TCPP) as a photosensitizer, and a sacrificial electron donor for TCPP. In this system, effective photoinduced hydrogen evolution was observed.

The synthesis of a series of novel tetra-(benzo-24-crown-8)-phthalocyanines (Mg(II), Ni(II) and Co(II)) as well as a modified procedure for the free-base ligand and its Zn(II) and Cu(II) complexes are reported. The tendency of these phthalocyanines to undergo supramolecular cofacial dimerization induced by interaction with a viologen ($N,N$-di(but-3-ynyl)-4,4$\prime$-bipyridinium) was investigated by UV-vis absorption and EPR spectral studies in solution. The nature of the metal cation in phthalocyanine, the concentration, as well as the solvent all influenced the assembly processes.

A linear porphyrin-based tecton bearing two 4,4$\prime$bipyridinium units (viologens) and two monomethyl-ether triethylene glycol-substituted phenyl substituents at the meso positions was synthesized and characterized. The latter was involved in the redox-triggered formation of linear supramolecular assemblies with cucurbit[8]uril (CB[8]) cavitands in aqueous media. The CB[8]-promoted intermolecular $\pi$-dimerization of the viologen cation radicals introduced at the meso positions of the porphyrin platform has been brought to light through the diagnostic signatures of the 1:2 host-guest ternary caviplexes formed between viologen and CB[8] and by spectroscopic data collected after electrochemical reduction of the viologen-based tectons.

The electrochemical behavior of viologen self-assembled monolayer has been investigated with QCM, which has been known as ng order mass detector. The self-assembly process of viologen was monitored using resonant frequency (ΔF) and resonant resistance (R). The QCM measurements indicated a mass adsorption for viologen assembling on the gold surface with a frequency change of about 300, 135 Hz and its surface coverage (Γ) was calculated to be 5.02 × 10^-9 and 1.64 × 10^-9mol/cm². A reversible redox process was also observed and analyzed with an ionic interaction at the viologen/solution interface using ΔF.