Fabrication and optical nonlinearities of composite films derived from the water-soluble Keplerate-type polyoxometalate and chloroform-soluble porphyrin

Abstract

Composite films derived from the water-soluble Keplerate-type polyoxometalate (NH4)42[Mo132O372(CH3COO)30(H2O)72]·ca. 300H2O·ca. 10CH3COONH4 (denoted (NH4)42{Mo132}) and chloroform-soluble tetraphenylporphyrin perchlorate [H2TPP](ClO4)2 are successfully fabricated by a layer-by-layer self-assembly method and characterized by UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The structure of the {Mo132} and [H2TPP](2+) in the films remain intact in light of the results of UV-vis spectroscopy and XPS. UV-vis spectra measurements reveal that the amounts of deposition of {Mo132} and [H2TPP](2+) remain constant in every adsorption cycle in the composite films assembly process. Nonlinear optical properties of the composite films have been investigated by using the Z-scan technique at a wavelength of 532 nm and pulse width of 7 ns. The results show that the composite films have notable nonlinear saturated absorption and self-defocusing effects. The combination of {Mo132} with [H2TPP](2+) can result in composite films with remarkably enhanced optical nonlinearities. The interfacial charge transfer induced by laser from porphyrin to POM in the films is thought to play a key role in the enhancement of NLO response. The third-order NLO susceptibility χ((3)) of the composite films increases with the increase of film thickness.

A Visual Discrimination of Existing States of Virus Capsid Protein by a Giant Molybdate Cluster

“…Suitable fits of the data points, corresponding to two possible 3d doublets of Mo in different oxidation states of Mo(VI) and Mo(V), were achieved using two pairs of Lorentzian–Gaussian functions. The peaks centered at 232.4 and 235.5 eV were assigned to Mo(V), while those at 233.6 and 236.6 eV were attributed to Mo(VI), respectively [ 39 , 40 ]. Semi-quantitative calculations showed that the characteristic ratio of peak area for Mo(VI) and Mo(V) was 1.45:1 for [Mo 132 ] ( Table 1 ), which was slightly over the value of 1.2 calculated from the ratio of 72 Mo(VI) to 60 Mo(V).…”

“…The coding sequences and preparation of major capsid protein (L1) for HPV 16 followed the procedures described in a previous work where pET-30a vector and BL21 Star TM (DE3) were employed for better expression [ 40 ]. Briefly, the recombinant Escherichia coli strain BL21 Star TM (DE3) was cultured at 37 °C with stirring at 220 rpm, where the bacteria were induced by 0.1 mM IPTG.…”

“…The coding sequences of HPV 16 pep1–401 and pep401–495 were the same as the corresponding segment of HPV 16 L1 [ 40 ]. The pET-30a vector containing the respect gene was transformed into Escherichia coli strain BL21 Star TM (DE3) and cultured at 37 °C.…”

“…The coding sequences of HPV 16 pep1-401 and pep401-495 were the same as the corresponding segment of HPV 16 L1 [40]. The pET-30a vector containing the respect gene was transformed into Escherichia coli strain BL21 Star TM (DE3) and cultured at 37 • C. The experimental conditions and method used for their expression and the following purifications were the same as that of the HPV 16 L1 protein described above.…”

Crystalline Porous Materials for Nonlinear Optics

“…The results show that the highly delocalized π-electron conjugation systems produced by the electron donor-acceptor of porphyrin-POM hybrid is considered to be the key to produce a strong NLO response. [183][184][185][186] [56] Copyright 2020, Royal Society of Chemistry. d) Schematic illustration of the TPI-COF with high crystallinity.…”