A series of sterically hindered catecholphenols was synthesized by the reaction 4,6-di-tert-butyl-3-methoxymethylcatechol with resorcinol, 4,6-di-tert-butylresorcinol, orcinol, 3,5-dimethoxyphenol, α- and β-naphthol. The structure of the obtained compounds was proved by NMR, IR and mass spectroscopy. The structure of 4,6-di-tert-butyl-3-[(2-hydroxynaphthalen-1-yl)methyl]benzene-1,2-diol was determined by single-crystal X-ray diffraction. The radical scavenging of obtained compounds were determined using 2,2-diphenyl-1-picrylhydrazyl radical test.

A series of 4-hydroxy-4,9-dihydro-4H-xanthen-4-one derivatives were synthesized using the oxidative cyclization reaction of space-shielded catecholphenols. The structure of 1,3,5,7-tetra-tert-butyl-4a,8-dihydroxy-9H-xanthen-4(4aH)-one was determined by X-ray diffraction analysis (CCDC 2345899). The antiradical properties of new compounds were studied by their reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH radical).

In this paper, we consider a series of new compact A-π-D photoinitiators consisting of donor aromatic fragments (naphthalene, anthracene, phenanthrene, pyrene and perylene) and a strong acceptor tricyanoethylene group—aryltricyanoethylenes (ArTCNEs). Spectral, photophysical, and electrochemical characteristics of ArTCNEs are studied. One-photon (with LED@405 nm) and two-photon (λ = 780 nm, impulse duration of 100 fs) photopolymerization of PETA can be effectively initiated by ArTCNEs with the tertiary amine N,N-dimethylcyclohexylamine DMCHA and/or the iodonium salt diphenyliodonium chloride Iod. Based on results of experiments on photodegradation, photopolymerization and EPR spectroscopy, a photoinitiation mechanism of radical photopolymerization was proposed for two-component (AntTCNE/DMCHA) and three-component (AntTCNE/DMCHA/Iod) initiating systems. The composition containing PerTCNE/DMCHA as a photoinitiator demonstrated the best reactivity under two-photon nanolithography conditions: the polymerization threshold was 2 mW at a laser beam scanning speed of 100 μm/s, and the widest fabrication window of 11 mW was typical for it. As an example, 3D “cage” structures were fabricated using the AntTCNE-based composition, and the test structure resolution parameters, such as the minimum line width and the distance between lines of 80 and 400 nm, respectively, were achieved. MTT experiments with human dermal fibroblasts showed promising preliminary biocompatibility of the resulting polymers, which opens up possibilities for using the obtained materials in biological applications.

In this paper, we consider a series of new compact A-π-D photoinitiators consisting of donor aromatic fragments (naphthalene, anthracene, phenanthrene, pyrene and perylene) and a strong acceptor tricyanoethylene group – aryltricyanoethylenes (ArTCNE). Spectral, photophysical, and electrochemical characteristics of ArTCNE have been studied. One-photon (with LED@405 nm) and two-photon (λ = 780 nm, impulse duration of 100 fs) photopolymerization of PETA can be effectively initiated by ArTCNE with the tertiary amine N,N-dimethylcyclohexylamine DMCHA and/or the iodonium salt diphenyliodonium chloride Iod. Basing on results of experiments on photodegradation, photopolymerization and EPR spectroscopy, a photoinitiation mechanism of radical photopolymerization was proposed for two-component (ArTCNE/DMCHA) and three-component (ArTCNE/DMCHA/Iod) initiating systems. The composition containing PerTCNE/DMCHA as a photoinitiator demonstrated the best reactivity under two-photon nanolithography conditions: the polymerization threshold was 2 mW at a laser beam scanning speed of 100 μm/s, and the widest fabrication window of 11 mW is typical for it. As an example, 3D “cages”-structures were fabricated using the AntTCNE-based composition, and the test structure resolution parameters such as the minimum line width and the distance between lines of 80 and 400 nm, respectively, were achieved. MTT experiments with human dermal fibroblasts showed the non-cytotoxicity of the resulting polymers, which opens up possibilities for using the obtained materials in biological applications.