Preparation, Characterization and Photoelectric Properties of Hybrid Langmuir-Blodgett Films of Alkynylplatinum(II)-Zinc(II) Porphyrinate/Heteropolyoxometalate

A new family of organometallic/inorganic hybrid Langmuir-Blodgett (LB) films, consisting of rigid-rod alkynylplatinum(II)-zinc(II) porphyrinate complex (OMA) as the π-conjugated donor-acceptor-type molecule, molybdophosphoric heteropolyacid and heteropolyacid salt (POM = H3PMo12O40, Na5IMo6O24, abbreviated as HPMo12and NaIMo6, respectively) of the Keggin and Anderson structures as the inorganic composite, were prepared and characterized by π-A isotherms, UV-vis absorption and luminescence spectra, scanning tunneling microscopy and surface photovoltage spectroscopy. Our experimental results indicate that stable, well-defined and well-organized Langmuir and LB films have been formed in pure water and POM subphase. Luminescence spectra of these hybrid LB films show that HPMo12can increase the emission intensity of OMA to some extent. These LB composites show good photovoltage responses and a photovoltage of 11. 1 μV can be obtained for the OMA/HPMo12system when it is excited by light. The 3-layer LB films on ITO wafer can also display intriguing electrical conductivity behavior and the tunneling current amounts to ±100 nA when the voltage is set at -0. 7-2. 5 and -1. 3-0. 8 V for OMA/HPMo12and OMA/NaIMo6hybrid LB films, respectively.