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A photochemically bifunctional compound was obtained. Its molecule includes the spironaphthoxazine and dansylamino fragments. This compound exhibits both photochromic and luminescent properties. Its spectroscopic characteristics were studied in different solvents. The electronic systems of two constituent fragments do not interact with each other.

In an approximation of the generalized valence force field, the frequencies and forms of the normal vibrations of the free molecule of spiroanthraceneoxazine (SAO) are calculated. The vibrational spectra of SAO are measured: the IR absorption spectra in an NaCl disk and the Raman spectra in a KBr disk. The calculated and experimental data were correlated with the aid of a method of refined initial data. The results obtained agree with the calculated and experimental spectra of model and related compounds.

The behavior of 1,3,3-trimethylspiro[indoline-2,3′-2H-naphtho[2,1-b][1,4]oxazine under plastic deformation was studied on high-pressure Bridgman anvil-type apparatus at 0.5–4 GPa and room temperature.

A direct nitration of photochromic spirooxazines was carried out by three different methods. The molecular structure of main products was determined by NMR 1H and 13C spectra. The nitration mechanisms were proposed. It was shown that only nitration by mixture of nitric and sulfuric acids gives photochromic compounds with nitrogroup in aryloxazine ring.

The excited-state intramolecular proton transfer (ESIPT) in some 2,4,5-triarylimidazoles (TAIs) is studied by the methods of steady-state luminescence and femtosecond laser absorption spectroscopy. It is found that ESIPT in 4,5-diphenyl-(2-hydroxyphenyl)imidazoles occurs both in solutions at ambient temperature and in glassy matrices at 77 K. In the case of 4,5-diphenyl-(2-hydroxynaphthyl)imidazole, a rotation of molecular fragments is necessary for ESIPT to occur, which results in the absence of ESIPT at 77 K. The characteristic times of intramolecular processes in the excited state of TAIs are measured by the method of femtosecond absorption spectroscopy. It is shown that the ESIPT time in TAIs depends on the molecular structure—it is extremely short (≤100 fs) in molecules with a planar reaction center and three times as long in TAIs with a non-planar reaction center—being determined by the time of conformational rearrangement.

Intramolecular processes in electronic-excited states of 2,4,5-triarylimidazole molecules were studied by femtosecond laser spectroscopy. Experiments were carried out with two types of compounds, namely, those experiencing intramolecular proton transfer and two model compounds in which it is impossible. Schemes of the processes studied were proposed and the characteristic rate constants were determined. The excited-state intramolecular proton transfer (ESIPT) in the molecules with planar structure of the reaction center is a very fast process (≤100 fs). If the reaction center has a nonplanar structure and, hence, the intramolecular hydrogen bond is weakened, the ESIPT time is determined by the time of conformational rearrangement of the molecule.

Excited-state intramolecular proton transfer (ESIPT) in the 2,4,5-triarylimidazole molecules was studied by spectral-luminescent technique. For 4,5-diphenyl-(2-hydroxyphenyl)imidazoles, the ESIPT occurs in both liquid and glassy matrices at 77 K. For 4,5-diphenyl-(2-hydroxynaphthyl)imidazole, the ESIPT requires rotation of molecular fragments and is not observed at 77 K.

Direct bromination of photochromic compounds of the spironaphthoxazine and spironaphthopyran series was performed using N-bromosuccinimide to obtain both photochromic bromine-substituted spiro compounds and nonphotochromic 2-(naphtho[1,2-d]oxazol-2-yl)-3H-indolium bromides. The structures of the resulting products were established by NMR spectroscopy and mass spectrometry. The mechanism of bromination taking into account the involvement of both closed and open (colored) forms of spiro compounds was proposed.

Electronic absorption and NMR spectra of solutions of photochromic spironaphthoxazines (SNOs) were studied. The addition of an acid results in the formation of a salt of the colored form of SNO. For SNOs with nitrogen-containing electron-releasing substituents, the structure of the product that formed depends on the acid concentration being the salt of the mono- or dication.

Primary processes in spironaphtopyran (SNP), spironaphtoaxazine (SNO) and spirophenantrooxazine (SPO) after excitation by the femtosecond light pulse with the carrier wavelength 308 nm were studied by the absorption `pump-probe' method with femtosecond time resolution. Probing was performed by means of the super-continuum light pulse with the carrier wavelength in the range 420–580 nm. Registration of the photoinduced absorption spectra dynamics allowed to observe time evolution of all intermediates. It appeared that photoinduced transformation of all three compounds has the same mechanism. Kinetic scheme is suggested and all rate constants entering this scheme are determined.

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.

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.

Absorption, luminescence, and luminescence polarization spectra of associates of photochronic molecules of nitrosubstituted indolinospiropyranes in the closed form in polymeric films at high temperatures were studied. The efficiency of the formation of the associates depends on the structure of the photochrome molecules and the nature of the polymeric matrix. A scheme of phototransformations of the associates taking into account the exciting light wavelength was suggested.

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.

A new photochromic compound belonging to the class of spiro(indoline-naphthoxazines) was synthesized. Nitration of this compound was carried out and the structures of two photochromic nitro-substituted products were determined. The photochromic properties of the products were studied in solvents of different polarity.

The spectral and photochromic properties of bispiroanthro-bis-oxazine (bis-SAO) in toluene, DMF, and polystyrene films were investigated in the 77–300 K interval. It is shown that the long-wave part of the absorption spectrum of the starting form of the molecule is formed by three-electron transitions localized in the anthro-bis-oxazine fragment. The directions of the oscillators of these transitions relative to the nuclear. backbone of the molecule are proposed on the basis of luminescence polarization data. It is proposed that the photochromic properties of the solutions are determined by the existence of bis-SAO molecules in dimer form.

The photochromic properties of 1′,3′,3′-trimethylspiro[indolin-2′,3-3H-anthraceno[2,1-b][1,4]-oxazine] (SAO) in solutions of different polarity [n-BuOH and petroleum ether (PETh)] were studied. It was established that the quantum yield of the photocoloration φAB and the energy of activation of the thermal decolorization Ea in the PETh depend on the temperature; this is not the case in n-BuOH. The luminescence properties of SAO were investigated. It was found that the spectrum of the excitation of the luminescence in PETh depends on the temperature. These features, as well as the slower thermal decolorization of the colored form of SAO in PETh by comparison with the solutions in n-BuOH, are explained by the presence of dimers of the SAO molecules in nonpolar media in the temperature range investigated (77–300 K), whereas the SAO molecules already occur in the monomeric state at 150 K in the polar n-BuOH.

The influence of temperature and concentration on the spectral polarization properties of the luminescence and absorption of molecules of the original form of photochromic spiroanthrooxazine (SAO) in petroleum ether and polyethylene was investigated. It was shown that the long-wave part of the absorption spectra of the molecules is formed by at least two π-π*-type electronic transitions, the oscillators of which are mutually orthogonal. It is suggested that the SAO molecules form dimers in nonpolar media through dipole-dipole interaction, and at high concentrations they also form higher associates. Dimers stable in the ground state dissociate when excited to the second electronic transition with a rate constant of 1012–1013 s−1.

1′,3′,3′-Trimethylspiro[indoline-2′,3-3H-anthraceno[2,1-b][1,4]oxazine] was synthesized. The compound has photochromic properties in solutions and in polymeric matrices. It was found from the spectral data that the colored form of the spiroanthrooxazine exists in a quinoid form and is characterized by a positive solvatochromic effect.

The photochromic properties of nitro-substituted spironaphthooxazines in polymer matrices of different polarity were investigated and the quantum yields of photocoloration and parameters of the dark decolorization reaction, which is a disperse process, were determined. The features of the behavior of the nitro-substituted spironaphthooxazines are determined by the more efficient reaction of the photoinduced form with the medium, which is the consequence of stabilization of the bipolar structure of the molecule of the colored form.

Two new photochromic compounds each containing two substituents with long alkyl chains in different parts of a molecule were synthesized by a sequence of direct reduction, acylation, and nitration reactions of substituted spirobenzopyrans. The structures of the compounds synthesized were determined using the 1H NMR spectra.

Nitration of photochromic spirophenanthrooxazine with three different reagents (cupric nitrate, NaNO2 in acetic acid, and HNO3-H2SO4) was studied. The major reaction products were specified and characterized by 1H and 13C NMR and mass spectra. The mechanisms of their formation were proposed. Only the nitration with a mixture of nitric and sulfuric acids yielded a photochromic product containing the nitro group in the phenanthrene fragment.

Electrochromic properties of 1′,3′,3′-trimethyl-6-piperidino- and-morpholinospiro[indoline-2′,3-3H-naphtho[2,1-b][1,4]-oxazines] resulting from their ionization and the formation of intermediate products were studied. The characteristic features of the photochromic behavior of these compounds are positive solvatochromism for absorption spectra of a colored form and an increase in the rate constant for thermobleaching with increasing solvent polarity.

7-Nitro- and 8-nitroderivatives of 1′,3′,3′-trimethylspiro[indoline-2′,3-3H-naphtho[2,1-b][1,4]oxazine] were synthesized, the last of them being prepared by direct nitration. The introduction of the nitro group stabilizes a bipolar colored form, the highest stability being exhibited when the NO2 group is the 8-position.

Photocoloration of spyropyran in polymethyl methacrylate and polystyrene matrices at 293 and 77 K results in the formation of a set of photoproducts with individual spectral characteristics, and the structure of a certain stereoisomer was assigned to each photoproduct based on these characteristics.

1. The position of the maximum in the absorption and fluorescence spectra of symmetrical derivatives of 1,4-bis-(4,5-diphenyl-1H-imidazol-2-yl)benzene (I) and 1,4-bis(4,5-diphenyl-2H-imidazol-2-ylidene)-2,5-cyclohexadiene (II) is determined by the donor-acceptor properties of the substituents in the para-position of the phenyl rings and the nD value of the solvent, the influence of which is strongly pronounced in the case of the quinoid compounds. 2. Data on the solvatochroism of compounds of series (I) were used to determine the changes in the polarizability in the transition S0 → S1, which depend on the donor-acceptor properties of the substituents.

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.

1. The PMR spectra of the closed forms of spironaphthopyran and spironaphthooxazine were interpreted. The PMR spectra of the photoinduced forms of these compounds were obtained for the first time. 2. The open form of spironaphthooxazine in nonpolar solvents was found to have the quinoid structure of one of the trans isomers, while there is a shift in the equilibrium toward the bipolar structure in polar solvents.

1. The processes of the photocoloration and dark decoloration of indolinospironaphthooxazine in polymeric films are described on the assumption of the existence of two types of molecules of the initial and colored forms. The quantum yields of the photocoloration, the rate constants, and the energy of activation of the decoloration reaction are determined. 2. A photophysical mechanism for the process of the photocoloration of indolinospironaphthooxazine, including the participation of the cis-cisoid isomer, is proposed.

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.

1. The spectral and kinetic properties of the photoinduced colored species in a solution of 6-nitrospiropyrans in hexane are determined by associates of colored and colorless species. 2. The spectral bands at 580 and 615 nm belong to associates of the monomeric colored and colorless state of type BB and AB, the band at 520–540 nm belongs to the associate of the dimer of the colorless state of type ABA2, and the state with charge transfer (A+B−)An, formed in the reaction of ABA2 with the colorless state, is responsible for the absorption band at 670 nm. 3. The highly polar state (A+B−)An, which takes up other states, forms high-molecular associates. 4. The thermal decolorization of states AB, BB, and ABA2 takes place one order of magnitude more rapidly than that of state (A+B−)An. 5. The bulky alkyl substituent on the nitrogen atom in spiropyran hinders association of the colorless form and the formation of associate ABA2 and creates additional hindrances to the reaction of decolorization in the state of isomerization and cyclization.

The possibility of slowing down the thermal bleaching of the coloured form of indolenospiropyranes with electron-donor substituentsin the chromene part of the molecule by chemically combining the photochromic molecules with the main or with a pendant polymeric chain is discussed. It has been established that, in solutions, the rate of bleaching is reduced by a factor of 5–10 as compared with the rates for the low-molecular weight analogues.

1. Copolymers of 1,3,3-trimethyl-5-methacryloylamino-6′-nitro-8′-methacryloylhydroxy-methylspiro(indoline-2,2′-[2H-1]-benzopyran) with different alkyl methacrylates and styrene were prepared. The copolymers have different solubility as a function of the nature of the comonomer. 2. The photochromic properties of the prepared copolymers in solutions were studied. The complex nature of the kinetics of bleaching of the solutions of copolymers is due to the inclusion of the spyropyran molecules in the main chain of the polymer.

Thermally induced formation of colored complexes which result in the amorphous and crystalline states of solid compounds takes place in a concentrated solution of 6-nitrospiropyrans in a polar solvent.

1. The solvatochromism of 1,4-bis(4,5-diphenyl-2H-imidazol-2-ylidene)-2,5-cyclohexadiene (I) has been studied. It has been shown that the main contribution to the displacement of the long-wavelength absorption maximum is made by the dispersion interaction. 2. The hypsochromic shift of the maximum of the long-wavelength absorption in the spectrum of (I) as the temperture of solutions in benzene and hexane is increased is caused by changes in the intermolecular interaction, rather than the formation of a biradical form.