Organometallic Gold(I) Acetylide/Polyoxometalate Hybrid Langmuir-Blodgett Films: Preparation, Characterization, and Photoelectric Properties

Abstract

A new series of organometallic/inorganic hybrid Langmuir-Blodgett (LB) films containing an organometallic gold(i) aryleneethynylene metal complex (OMA) as the π-conjugated organometallic molecule and a polyoxometalate (POM, POM = H3BW12O40, H6As2W18O62, or H6P2Mo18O62) of the Keggin and Dawson structure as the inorganic composite, were prepared and characterized by π–A isotherms, UV-vis absorption spectra, photoluminescence spectra, atomic force microscopy imaging, scanning tunnelling microscopy, and surface photovoltage spectroscopy. Our experimental results indicate that stable, well defined and well organized Langmuir and LB films are formed in pure water and polyoxometalate subphases. There is a quenching effect in the luminescence of the gold(i) complex when it is made into the LB films. The OMA/POM hybrid LB films display strong photovoltage effect in the UV-vis region. The photovoltage response of OMA/H6As2W18O62 can be as high as 3338 μV. OMA/POM monolayer films show good electrical conductivity, and the tunnelling current for a OMA/H3BW12O40 monolayer film amounts to 50 to approximately –100 nA when the voltage is set at ±9 V.

Reaction Controlled Assemblies of Polyoxotungstates (-molybdates) and Coordination Polymers

“…SPS and EFISPS are effective methods to investigate the processes of dye sensitization and photocatalysis and the photoelectric properties of a semiconductor . However, to the best of our knowledge, the study of surface photovoltaic (SPV) behaviors of POM-containing materials is in its preliminary stage, with very limited publications relevant to the topic available. , In this paper, we employed SPS and EFISPS to investigate the behaviors of photogenerated electrons and the photoelectric properties of compounds 3 − 5 . Such a characteristic indicates that these compounds can be used as potential photocatalytic framework materials for the degradation of organic molecules.…”

Light-Emitting Self-Assembled Materials Based on d8 and d10 Transition Metal Complexes

“…940 Wong and co-workers recently reported a class of hybrid Langmuir−Blodgett (LB) films consisting of an alkynylgold(I) complex, [PPh 3 PAuCC−(N-butylcarbazole)−CC− AuPPh 3 ], and a polyoxometalate (POM). 941 The gold(I) complex was found to form stable and well-defined LB films in pure water and POM subphases. The presence of POM would lead to a certain degree of quenching of the luminescence of the alkynylgold(I) complex, and the [Au]/ POM hybrid films were observed to show a strong photovoltage effect in the UV−visible region.…”

“…The presence of POM would lead to a certain degree of quenching of the luminescence of the alkynylgold(I) complex, and the [Au]/ POM hybrid films were observed to show a strong photovoltage effect in the UV−visible region. 941 By changing the bridging carbazole bis-alkynyl ligand into a 9,9-bis(4ethynylphenyl)fluorene ligand, luminescent LB films with near-white emission have been obtained because of the dual emissive nature of the hybrid material. 942 On the other hand, the gold(I) complex, [Au 2 (dppp)-(BIT) 2 ]•(CF 3 CO 2 ) 2 (dppp = bis(diphenylphosphino)propane; BIT = 2-benzimidazolethiol), was found to readily interconvert between two forms (Figure 208).…”

“…Wong and co-workers recently reported a class of hybrid Langmuir–Blodgett (LB) films consisting of an alkynylgold­(I) complex, [PPh 3 PAuCC–( N -butylcarbazole)–CC–AuPPh 3 ], and a polyoxometalate (POM) . The gold­(I) complex was found to form stable and well-defined LB films in pure water and POM subphases.…”

Large Tripodal Spacer Ligands for the Construction of Microporous Metal–Organic Frameworks with Diverse Structures and Photocatalytic Activities

“…[42] These resultsw ereo btained by surface photovoltage spectroscopy (SPS). Therew as one clear band in the SPS resultso f 1and 2 in the range of l = 300-600 nm ( Figure S6 in the Supporting Information).…”