Sensing Behavior of Metal-Free Porphyrin and Zinc Phthalocyanine Thin Film towards Xylene-Styrene and HCl Vapors in Planar Optical Waveguide

Abstract

The sensing behavior of a thin film composed of metal-free 5, 10, 15, 20-tetrakis (p-hydroxy phenyl) porphyrin and zinc phthalocyanine complex towards m-xylene, styrene, and HCl vapors in a homemade planar optical waveguide (POWG), was studied at room temperature. The thin film was deposited on the surface of potassium ion-exchanged glass substrate, using vacuum spin-coating method, and a semiconductor laser light (532 nm) as the guiding light. Opto-chemical changes of the film exposing with hydrochloric gas, m-xylene, and styrene vapor, were analyzed firstly with UV-Vis spectroscopy. The fabricated POWG shows good correlation between gas exposure response and absorbance change within the gas concentration range 10–1500 ppm. The limit of detection calculated from the logarithmic calibration curve was proved to be 11.47, 21.08, and 14.07 ppm, for HCl gas, m-xylene, and styrene vapors, respectively. It is interesting to find that the film can be recovered to the initial state with trimethylamine vapors after m-xylene, styrene exposures as well as HCl exposure. The gas-film interaction mechanism was discussed considering protonation and π-π stacking with planar aromatic analyte molecules.

Photochemical α-Aminonitrile Synthesis Using Zn-Phthalocyanines as Near-Infrared Photocatalysts

“…The proposed mechanism for the conversion of amines to α-aminonitriles using ZnPc, TMSCN, O 2 , and NIR light can be found in Scheme 4. Upon irradiation in the Q-band of ZnPc with near-infrared light (λ = 700−800 nm) and intersystem crossing, 55 the photosensitizer is obtained in a 3 (π−π*) state 3 ZnPc*, which is known to convert 3 O 2 to 1 O 2 through Dexter energy transfer in a very efficient manner (Φ Δ = 0.67, DMSO). 56,57 The intersystem crossing to the triplet state is facilitated by the spin-orbit coupling of the heavy zinc atom.…”

“…The proposed mechanism for the conversion of amines to α-aminonitriles using ZnPc, TMSCN, O 2 , and NIR light can be found in Scheme . Upon irradiation in the Q-band of ZnPc with near-infrared light (λ = 700–800 nm) and intersystem crossing, the photosensitizer is obtained in a 3 (π–π*) state 3 ZnPc*, which is known to convert 3 O 2 to 1 O 2 through Dexter energy transfer in a very efficient manner (Φ Δ = 0.67, DMSO). , The intersystem crossing to the triplet state is facilitated by the spin-orbit coupling of the heavy zinc atom. , Electron transfer from the amine substrate I to singlet oxygen generates an aminium radical cation II and superoxide, which then abstracts a hydrogen atom from the α-position of II to generate the respective iminium ion III and a hydroperoxide anion IV . Alternatively, the iminium ion III and hydroperoxide anion IV could be formed directly via a concerted pericyclic reaction .…”

Arylenevinylene Oligomer-Based Heterostructures on Flexible AZO Electrodes

“…Thus, it allowed the conformational adaptation of the TPyP molecules to their local environment. In turn, ZnPc molecule macrocycles preferentially lie parallel to the surface with their stacking axes inclining to the substrate [65,66]. In the case of a twisted molecule, such as the molecules of L13 and L78, the arrangement of the molecules does not respect any order when the molecules cover the ZnPc film.…”

Sulfonated Zinc Phthalocyanine Coating as an Efficient and Ecofriendly Corrosion Inhibitor for Copper Surfaces: An In Silico Led Design and Its Experimental Validation

“…63 The Zn 2p 3/2 and Zn 2p 1/2 peaks were observed at 1021.85 and 1045.05 eV, as given in Figure 8d. 64 For the ZnPc molecule, these peaks are observed to have slightly higher binding energies, and these could be ascribed to the interaction between the Zn atoms and the underlying copper substrate. The ZnPc-S-coated copper samples were placed in 3.5% NaCl solution (corrosive medium used in the study) for 12 h and then analyzed with XPS to find out whether the ZnPc-S protective layer was still present, thereby protecting the copper surface.…”