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The authors have studied the effect of pressure p of up to 2·5 × 103 MPa on the dielectric constant e and conductivity G of a number of iodine-doped polymers with a conjugation system. They have investigated polyphenylacetylene obtained on iron acetylacetonate, polyphenylacetylene obtained on a Ziegler catalyst, anionic polytolane and polyphenylbutadiine. It was found that after doping the values of e and G rise and begin to depend closely on p. The possible mechanism of this phenomenon is discussed.

The abrupt decrease of electric resistance of thin polymer dielectric films and metal-polymer compositions has been observed in the course of their uniaxial compression. At pressures exceeding the critical one the conductivity of some metal-polymer compositions has been found to be as high as that for such metals as titanium. The dependences of specimen resistance on thickness, temperature and uniaxial pressure strongly support a new mechanism fo polymer dielectric conductivity based on the pressure induced injection of current carriers from a metal to the dielectric conduction band.

The influence of high pressure and shear strain on conductivity G and capacitance C of non-metallic polyphthalocyanines with different macromolecule lengths and degrees of crosslinking have been studied. Both the G and C of the polymers was found to increase with compression. Similar phenomena were observed during the simultaneous action of high pressure and shear strain on the polyphthalocyanines (PPC). However, in the latter case, the change in G necessitates a lower pressure than for a single compression. Spectral studies show that the effect of pressure and strain of loaded samples on their electrophysical properties is not connected with the chemical structure of the PPCs, but is evidently due to a change in the average separation between regions of continuous conjugation. It was shown that the dimensions of these regions may be increased by preliminary thermal treatment of the PPC.

An “inverse” photo-chromism (photo-decolourization) has been found in the case of indolinospiropyranes having an electron donating substituent in 6′- and any other type of substituent in 8′-position in polar solvents and polymeric matrices. The quantum yield of the photo-decolourization in visible light has been found to increase with the spiropyrane content. Rapid spectroscopy confirmed the existence of a pigmented form in a photo-excitation of stereo-isomers.

A new approach to the formation of electrically conducting polymeric materials has been formulated. It is based on the phenomenon of pressure-induced injection of charge carriers from conducting particles into dielectric media. This process has been recently discovered by the authors. In practice, this approach can be accomplished by synthesizing macromolecules of proper dielectric next to the surface of a conducting filler. The experiments supporting the validity of the main assumptions are used to provide a background for the “polymerization filling” concept. The application of this principle makes it possible to obtain systems with larger specific conductivity than with the usual “blended” composites.

Synopsis The effect of high pressure or the combined action of high pressure and shear deformation on the conductivity G and capacitance C of metal-free polyphthalocyanines (PPhCs), differing in macromolecular size, order, and degree of crosslinking, has been studied. It has been found that both G and C increase with compression. A similar phenomenon is observed under the combined action of high pressure and shear deformation on PPhC, but in this case the critical pressure needed for change in G is lower than that observed in uniaxial compression experiments. Spectroscopic investigations show that the effects of pressure and deformation on the electrophysical properties of samples under load is not connected with changes in the chemical structure of PPhC, but appear to be due to the change in the average distance between the regions of continuous conjugation. The sizes of such regions may be increased by preliminary thermal treatment.

1. Irradiation of acetone solutions of spiropyrans with an OCH3 substituent in the 8' position leads to the formation of a stable colored form. The absorption band for this form appears only in the spectra of ketone solutions. 2. The formation this stable colored form proceeds with the absorption of light by an intermediate spiropyran form, the quantum yield for this process being 0.14.

The effect of pressure P up to 2.5 X 10/sup 3/ MPa on the dielectric constant element of and conductivity G of a number of conjugated polymers doped by iodine has been studied. Polyphenylacetylene prepared with FeAcAc, polyphenylacetylene obtained with Ziegler catalyst, anionic polydiphenylacetylene, and polydiphenylbutadiene were chosen for investigation. It has been found that after doping the values element of and G increase and strongly depend on P. The possible mechanism of this phenomenon has been discussed.

Some photoconductive and electrophysical properties of nickel phthalocyanine (NiPc) have been investigated under uniaxial compression over the range from atmospheric pressure up to 0.8 GPa. It has been found that the compression of samples increases their photoconductivity and causes a red-shift of the integral photocurrent spectrum of Nipc. Possible interpretations of the effects observed are discussed.

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.

1. 1-(β-Hydroxyrethyl)-3,3-dimethyl-6'-nitrospiro(indoline-2,2'-[2H-1]benzopyran)s (II) substituted by an electron-accepting group (Br, NO2) in position 8' exist in solution mainly in the ring-opened merocyanine form. The equilibrium constant (Ke) is two orders of magnitude greater than that of unsubstituted (II). 2. Compound (II) with an OCH3 group exists as two isomers in solution; Ke is solvent-dependent. 3. We have developed a procedure for the synthesis of 1-(β-methacryloylhydroxyethyl)-3,3-dimethyl-6'-nitro-8'-bromo(8'-methoxy)spiro (indoline-2,2'-[2H-1]benzopyran).