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2 Materials Science

2 2002

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Photoinitiation ability of some pentaaza-1,4-dienes

Novikova O. O., Syromyatnikov V. V., Avramenko L. F., Kondratenko N. P., Kolisnichenko T. M., Abadie M. J. M.

Materials Science

2002

Vol. 20, No. 4

19-28

1,5-bis(4-methoxyphenyl)-3-methyl-pentaaza-1,4-diene, 1,5-bisphenyl-3-(2`-oxyethyl)-pentaaza-1,4-diene and 1,5-bisphenyl-3-methyl-pentaaza-1,4-diene were studied by differential scanning photocalorimetry (DPC) and dilatometry methods as photoinitiators of radical polymerization of vinyl monomers. Photoinitiation abilities of the compounds investigated were compared with those of industrial photoinitiator IRGACURE 1 700. Pentaazadienes exibit a high initiation capacity, the activation energy of polymerization process in the presence of pentaazadiene compounds being lower than that for IRGACURE 1700. An increase of the initiator concentration results in a decrease of the rate of the process. The phenomenon can be explained by autoinhibition.

Molecules with bonds such as Xe-O between moieties and their application

Kondratenko P. O., Lopatkin Y. M., Kondratenko N. P.

Materials Science

2002

Vol. 20, No. 4

93-99

The molecules with the bond such as Xe-O (the bond is formed owing to the interaction of completely occupied atom orbital (AO) of xenon and partially occupied AO of triplet oxygen between moieties are investigated. These investigations have shown that all such molecules (diazoquinones, salt of diazonium, azides etc.) are characterized by considerable activity in lower excited states or upon the transfer of an additional electron into them. They allowed us to establish that the photodissociation of the diazonium cation or the molecule of azide is carried out owing to the predissociation into the dissociative tq state, and the q MO is located on the dissociative bond. The photodissociation of diazoquinones is carried out from the lower singlet tt state. The transfer of the electron into salt of benzenediazonium and phenylazides provides the necessary conditions for the dissociation of the molecule, nevertheless, it provides the opportunity of the sensitization of the dissociation process to the visible region of the spectra with dyes only of diazonium salts. The sensitization of the photolysis of azide is possible only with high-energy radiation that also allows us to use this substance, for example, for the registration of ionizing radiation.