The literature data on the radical and ionic linear polymerisation of mainly mono- and di-substituted acetylenes with a single carbon?carbon triple bond are considered and the known mechanisms of the acetylene polymerisation processes are discussed. Much attention is devoted to the copolymerisation of acetylenes with monomers of different types. The results of studies on molecular, supermolecular, and electronic structures of polyvinylenes are compared with their electrophysical properties. The bibliography includes 475 references.

https://iopscience.iop.org/article/10.1070/RC1976v045n04ABEH002642/pdf

Polymerisation of Acetylenes. The Structure and Electrophysical Properties of Polyvinylenes

A comparative analysis of the spectral and photochromic properties of nitrosubstituted indolinic spirobenzopyrans (SBPs) and spironaphthooxazines (SNOs) is presented. Formation of the same trans isomer of the SNO coloured form at any temperature over a wide range (77–300 K) is proposed contrary to the case of SBP for which the photoproduct structure depends on temperature. Such photochromic parameters as the quantum yields of photocolouration and spirobond CO dissociation, and the efficiency of photoinduced form stabilization are examined for nitrosubstituted SBPs and SNOs.

Peculiarities of photochromic behaviour of spiropyrans and spirooxazines

Thermochromism of Organic Compounds

New photochromic polymers having network structure have been studied. These polymers have been obtained on the base of spiropyrans (SP) with one or two polymerizable groups. It has been shown that the photochromic properties of SP molecules linked with macromolecules by one polymerizable group depend on supermolecular structure of network polymer. So, these SP molecules can be used as indicators of microheterogeneity of network polymer. It has been established that the photochromic behavior of SP molecules having two polymerizable groups is determined by the number of chemical bonds (one or two) of such a SP molecule with macromolecule. The copolymers of these SP molecules with alkyl methacrylates are of special interest because using these copolymers make it possible to create photochromic polymer material having large and adjustable time of storage of optical information.

Photochromic network polymers

Spectral and photochromic properties of spironaphthooxazines (SNOs) with piperidine and morpholine substituents have been studied at different temperatures in various solvents. It has been recognized that introduction of these substituents in naphthooxazine fragment leads to fluorescence of the initial form of SNO molecules at low temperatures, which disappears with temperature rise. The dependences of the photoinduced form in non-polar solvents. It is proposed that the coloured form of substituted SNOs has a bipolar structure with a positive charge on piperidine or morpholine nitrogen atom contrary to the quinonoic form of unsubstituted SNO.

Photochromism of spironaphthooxazines having electron-donor substituents

Examination of the available information shows that polymers of diverse structure — linear (with polyene and cumulene fragments), cyclolinear (including ladderlike), and three-dimensional — can be obtained by the polymerisation of diynes having conjugated and non-conjugated triple bonds. The structural course of the process is determined by the nature of monomer and catalyst and the conditions. Linear organometallic polymers, whose main chain comprises alternating double bonds and atoms of Group IV elements, can be obtained by the polyaddition of hydrides of these elements to αω-diynes. A list of 58 references is included.

http://iopscience.iop.org/0036-021X/41/8/R06/pdf/0036-021X_41_8_R06.pdf

Structural Course of the Polymerisation of Diynes

1.

Polarization fluorescence spectra of the photoinduced form of 1,3,3-trimethyl-6′-nitrospiro(indoline-2,2′0[1(2H)]-benzopyran) have been measured in petroleum ether at 77 and 113°K and the angles between the oscillators of the two electronic transitions have been determined.




2.

Irradiation of the solution at 77°K leads to the formation of a cis-cisoid isomer of the open form of the spiropyran, which, with a rise in the temperature, passes into the most stable stereoisomer of the colored form.

Polarization of the fluorescence of isomers of the photoinduced form of a nitro-substituted spiropyran at low temperatures

1.

We have measured the energy barriers to conversion of the colorless form of five indolinospiropyrans with different 8′-substituents.




2.

We have measured the dependence of the angle between the oscillators of the electronic transitions of the colored form of the spiropyrans on the donor-acceptor properties of these substituents.




3.

The introduction of substituents into the pyran fragment of the spiropyran molecule controls the pathway for the color reaction and the equilibrium among the stereoisomers of the colored form.

Effect of electron-donating and electron-accepting substituents on photo- and thermochromic properties of indolinospiropyrans

Polarization of fluorescence in the photoinduced form of 1,3,3-trimethyl-6′-nitrospiro(indoline-2,2′-[2h-1]benzopyran) in polymer films

1.

The colored stereoisomers all decolorize at about the same rate in polymeric matrices, and their existence cannot, therefore, account for the anomalous kinetic behavior of the copolymers.




2.

The properties of the polymeric matrix determine the course of the thermal and photochemical decoloration of copolymer films at temperatures below the glass point; onto these reactions there is superposed the independent decoloration of the colored stereoisomers of the spirocyanin.

V. D. Ermakova

Papers

Structural Course of the Polymerisation of Diynes

Polarization of the fluorescence of isomers of the photoinduced form of a nitro-substituted spiropyran at low temperatures

Effect of electron-donating and electron-accepting substituents on photo- and thermochromic properties of indolinospiropyrans

Polarization of fluorescence in the photoinduced form of 1,3,3-trimethyl-6′-nitrospiro(indoline-2,2′-[2h-1]benzopyran) in polymer films

The thermal decolorization of photochrome copolymers of indolinospiropyran