Oxidative polymerization of nickel(II) 5,15‐diphenyl porphyrin and nickel(II) 5,15‐bis(di‐3,5‐tert‐butylphenyl) porphyrin by oxidative chemical vapor deposition (oCVD) yields multiply fused porphyrin oligomers in thin film form. The oCVD technique enables one‐step formation, deposition, and p‐doping of conjugated poly(porphyrins) coatings without solvents or post‐treatments. The decisive reactions and side reactions during the oCVD process are shown by high‐resolution mass spectrometry. Owing to the highly conjugated structure of the fused tapes, the thin films exhibit an electrical conductivity of 3.6×10 −2 S cm −1 and strong absorption in the visible to near‐infrared spectral region. The formation of smooth conjugated poly(porphyrins) coatings, even on sensitive substrates, is demonstrated by deposition and patterning on glass, silicon, and paper. Formation of conductive poly(porphyrins) thin films could enable the design of new optoelectronic devices using the oCVD approach.

A novel atmospheric pressure plasma-initiated chemical vapor deposition (AP-PiCVD) approach toward the growth of conventional polymer layers is characterized and interpreted. A set of three methacrylate monomers (methyl, butyl, and glycidyl methacrylate) were investigated using ultrashort plasma discharges (ca. 100 ns) pulsed at various frequencies, covering a range of duty cycle from 0.1% to 0.000 316%. An unprecedented weight-average molar mass of 94 000 g mol −1 coupled to an outstanding thin film conformality and an excellent chemical functionalities retention was achieved for the best deposition conditions. Insights into the growth mechanisms in AP-PiCVD and their dependence on the monomer's intrinsic properties are provided.

While the solution‐phase synthesis of directly fused porphyrin tapes has been successfully developed in recent years, the deposition of these promising compounds in thin film form has remained a challenge. In this study, we report the simultaneous synthesis and deposition of conductive directly fused poly(porphyrin) coatings based on a substrate independent and up‐scalable oxidative chemical vapor deposition (oCVD) approach. A particular emphasis is given to the selection and sublimation conditions of the oxidant. The direct fusion of nickel(II) 5,15‐(diphenyl)porphyrin (NiDPP) is successfully achieved using three different oxidants, namely iron(III) chloride (FeCl3), copper(II) chloride (CuCl2) and copper(II) perchlorate hexahydrate (Cu(ClO4)2·6H2O). FeCl3 is demonstrated as the most suitable oxidant, allowing the formation of mainly singly‐fused poly(NiDPP) or conductive mainly doubly or triply‐fused poly(NiDPP) that strongly absorb in the NIR. High‐resolution mass spectrometry evidences the chlorination of the formed compounds as a side reaction. This chlorination can either be considered as a drawback by preventing the formation of large directly fused NiDPP oligomers or as an asset when targeting the formation of fully insoluble directly fused poly(NiDPP) coatings. Overall, the described oCVD approach opened up the possibility to tune the band gap, conductivity, and solubility of directly fused P(NiDPP) coatings.

A simple, efficient and scalable method for the atmospheric pressure plasma initiated chemical vapor deposition of conventional polymer is demonstrated. Ultra‐short square pulse dielectric barrier discharge, which allows high deposition rates even for plasma duty cycle as low as 0.01%, is used to deposit a glycidyl methacrylate (GMA) polymer layer. The polymer structure of the thin films is evidenced by matrix‐assisted laser desorption/ionization high‐resolution mass spectrometry. Polymer molecular weights up to 30 000 g mol−1 are found by size exclusion chromatography (SEC), highlighting the suitability of the plasma initiated CVD method for the deposition of polymer layers.

Oxidative chemical vapour deposition of (5,15‐diphenylporphyrinato)nickel(II) (NiDPP) with iron(III) chloride as oxidant yielded a conjugated poly(metalloporphyrin) as a highly coloured thin film, which is potentially useful for optoelectronic applications. This study clarified the reactive sites of the porphyrin monomer NiDPP by HRMS, UV/Vis/NIR spectroscopy, cyclic voltammetry and EPR spectroscopy in combination with quantum chemical calculations. Unsubstituted meso positions are essential for successful polymerisation, as demonstrated by varying the porphyrin meso substituent pattern from di‐ to tri‐ and tetraphenyl substitution. DFT calculations support the proposed radical oxidative coupling mechanism and explain the regioselectivity of the C−C coupling processes. Depositing the conjugated polymer on glass slides and on thermoplastic transparent polyethylene naphthalate demonstrated the suitability of the porphyrin material for flexible optoelectronic devices.

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A comprehensive mass-spectrometry study of a set of poly(alkyl acrylate) layers synthesized by atmospheric pressure plasma-initiated chemical vapor deposition (AP-PiCVD) is provided. High-resolution mass spectrometry investigations demonstrate that exposure of the alkyl acrylate monomers to ultra-short and lowfrequency plasma pulses produces a defined number of radical and neutral fragments, which can play both the roles of polymerization initiation or termination groups. Further inquiries illustrate the competition between a conventional free-radical polymerization pathway and plasma-polymerization. On the basis of the massspectrometry observations and the bond dissociation energies calculated by density functional theory, guidelines are made to select appropriate AP-PiCVD monomers. K E Y W O R D Satmospheric-plasma CVD, conventional polymerization, high-resolution mass-spectrometry, nanopulsed discharge, polymerization mechanisms 1 | INTRODUCTION In many synthesis reactions, plasma provides a convenient alternative to thermal heating [1] or chemical reactants. [2] Noticeably, plasma-enhanced chemical vapor deposition (PECVD) processes can lead to the simultaneous lowtemperature synthesis and deposition of crystalline metal oxide thin films on polymer substrates [3] or ensure the "polymerization" of chemically non-polymerizable precursors. [4,5] The PECVD of many inorganic and organic materials has already been reported and the fine-tuning of the PECVD parameters, e.g., the composition of the plasma gas and the plasma excitation mode, can trigger a wide range of reactions, including the reduction of metal salts, [6] the oxidative polymerization of aromatic compounds, [2] and the free-radical polymerization of vinylene monomers. [7] Nevertheless, due to the intrinsic nature of plasmas, consisting of many reactive species with a wide energy range, a nonnegligible number of side reactions occurs. [2] As a consequence to the non-specificity of plasma-induced reactions and the sensitivity of the organic bonds, the chemical structure of monomers is only partially retained and the resulting PECVD This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Mass spectrometry imaging is a technique uniquely suited to localize and identify lipids in a tissue sample. Using an atmospheric pressure (AP-) matrix-assisted laser desorption ionization (MALDI) source coupled to an Orbitrap Elite, numerous lipid locations and structures can be determined in high mass resolution spectra and at cellular spatial resolution, but careful sample preparation is necessary. We tested 11 protocols on serial brain sections for the commonly used MALDI matrices CHCA, norharmane, DHB, DHAP, THAP, and DAN in combination with tissue washing and matrix additives to determine the lipid coverage, signal intensity, and spatial resolution achievable with AP-MALDI. In positive-ion mode, the most lipids could be detected with CHCA and THAP, while THAP and DAN without additional treatment offered the best signal intensities. In negative-ion mode, DAN showed the best lipid coverage and DHAP performed superiorly for gangliosides. DHB produced intense cholesterol signals in the white matter. One hundred fifty-five lipids were assigned in positive-ion mode (THAP) and 137 in negative-ion mode (DAN), and 76 peaks were identified using on-tissue tandem-MS. The spatial resolution achievable with DAN was 10 μm, confirmed with on tissue line-scans. This enabled the association of lipid species to single neurons in AP-MALDI images. The results show that the performance of AP-MALDI is comparable to vacuum MALDI techniques for lipid imaging.