Spiropyrans and spirooxazines. 1. Synthesis and photochromic properties of 9"-hydroxy- and 9"-alkoxy-substituted spironaphthooxazines

A procedure was developed for phase-transfer catalyzed alkylation of 5-hydroxyindolenine and 9"-hydroxy-substituted spiro[indoline-2,3"-naphtho[2,1-b]oxazines] by alkyl halides. New 9"-hydroxy- and 9"-alkoxy-substituted spironaphthooxazines, spirooxazinyloxyacetic acids, and their esters containing substituents with different length of the carbon chain in the indoline moiety were synthesized. The influence of the substituents on the spectroscopic properties of the starting and colored forms and the kinetic characteristics of photochromic transformations of 9"-substituted spironaphthooxazines in solutions and polymeric films was investigated. The bipolar merocyanine forms of spirooxazines were found to produce H-aggregates.     

Crown-containing spirooxazines and spiropyrans

Methods for the synthesis of new spironaphthooxazines containing an aza-15-crown-5 fragment in two different positions (5′ and 9′) were developed. The spectral and photochemical properties of these compounds suggest that two competitive complexation processes occur with alkaline-earth or rare-earth metal cations differing in efficiency and selectivity. A metal cation occupies the optimum position in the crown-ether cavity with respect to the donor oxygen atom of the merocyanine form of the dye and thus can affect more strongly its spectral and photochemical properties than in the case of intermolecular interaction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1974–1983, October, 1999.     

Synthesis, structures, and photochromic properties of N-aryl-3-indolylfulgides

New 3-indolylfulgides, viz., 3-[1-(1-aryl-5-methoxy-2-methyl-1H-indol-3-yl)ethylidene]-4-(1-methylethylidene)tetrahydro-2,5-furandiones, were synthesized. These compounds were obtained as E-isomers, as demonstrated by X-ray diffraction, electronic spectroscopy, and ¹H NMR spectroscopy. Fulgides exhibit photochromic properties in solution. The cyclic dihydrocarbazole photoisomers of indolylfulgides show fluorescence properties and are characterized by high thermal stability. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1423, July, 2008.     

Photo-and thermochromic spiranes 31.* Structure and photochromic properties of functionalized benzoxazine spiropyrans

An X-ray diffraction study gave the structure of a 4-oxohydro-2H-1,3-benzoxazine spiropyran with molecular formula C₂₈H₂₅N₃O₇, in which the π-electron-withdrawing formyl group is replaced with a chelatophoric hydrazine fragment containing a methoxy group. The structural parameters of this spiropyran were determined and compared with the data for similar spiropyrans. The photochromic properties of this compound in acetonitrile were studied in the presence of zinc ions. Dedicated to Professor A. F. Prozharskii on the occasion of his 70th jubilee. * For Communication 30 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1699–1706, November, 2008.     

Crown-containing spironaphthoxazines and spiropyrans. 2. Influence of metal cations on the photochromic properties of spironaphthoxazines linked with aza-15(18)-crown-5(6) ethers

Spironaphthoxazines linked with aza-15(18)-crown-5(6) fragments were synthesized and studied for the first time. Addition of alkaline-earth cations to solutions of crown-containing spironaphthoxazines causes a hypsochromic shift of the absorption band of the spiro form and a bathochromic shift of the absorption band of the merocyanine form, shifts the equilibrium to the merocyanine form, and changes the lifetime of the photoexcited merocyanine form. The spectral and kinetic data were used to propose a mechanism of complexation and calculate the stability constants of the resulting complexes. The complexation involves the crown fragment and the merocyanine oxygen atom. The type of the complex is determined by the cation nature and size.     

Synthesis and spectral-kinetic investigation of fulgimide-based photochromic autocomplexes of the dinitroquinoline series

Two new hybrid compounds, which belong to autocomplexes of the dinitroquinoline series and contain an NH spacer and fragments of photochromic fulgimides as donor components, were synthesized. These autocomplexes were used as ligands in the synthesis of cobalt-containing metal chelates. The spectral-kinetic study revealed that these compounds exhibit photochromism. The introduction of photochromic fulgimide moieties into the autocomplexes has no substantial effect on the spectral properties of the latter but influences the kinetics of photochromic transformations by decreasing their efficiency. Chelate complexes of the hybrid compounds with cobalt ions are characterized by the lowest efficiency of photochromic transformations due to a decrease in the intensity of activating radiation as a result of its absorption by the dinitroquinoline moieties, which are not conjugated with fragments of photochromic compounds. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1409–1416, July, 2008.     

Spiropyrans and spirooxazines 5. Synthesis of photochromic 8-(4,5-diphenyl-1,3-oxazol-2-y1)-substituted spiro[indoline-benzopyrans]

Photochromic spiro[indoline-benzopyrans] containing 4,5-diphenyloxazolyl group at position 8 of the benzopyran fragment have been obtained. New diphenyloxazolyl-substituted spiropyrans manifest considerably higher thermal stability of the merocyanine isomers than their naphthopyran analogs.     

Synthesis,structures, and selected chemical properties of 2-chloro- and 2-bromo-1,1-diferrocenylcyclopropanes

2-Chloro- and 2-bromo-1,1-diferrocenylcyclopropanes were synthesized as Z- and E-isomers with respect to the ferrocenyl substituent having a bisector orientation. The structure of Z-2-chloro-1,1-diferrocenylcyclopropane was confirmed by X-ray diffraction analysis. Treatment of the resulting monohalides with potassium tert-butoxide in dimethyl sulfoxide afforded 3,3-diferrocenylcyclopropene in 20% yield. The small ring in halogen-substituted diferrocenylcyclopropanes and diferrocenylcyclopropene is readily cleaved to give predominantly 3-ferrocenyl-1H-cyclopentaferrocene.     

Structures and photochromic properties of substituted spiroindolinonaphthoxazines

Six indolinospironaphthoxazines were studied by X-ray diffraction analysis. It was demonstrated that the electronic nature of the substituents in the naphthoxazine and indoline fragments has no substantial effect on the C_spiro−O and C_spiro−N bond lengths. Photocolorability of the compounds under study depends only slightly on the abovementioned bond lengths and correlates mainly with the energy of steric strain of the oxazine ring. The stability of the open forms of spiroindolinonaphthoxazines that formed upon photoirradiation is determined to a large extent by the electronic and steric nature of the substituents. The exception is the compound that contains the NO₂ group in the indoline fragment. In the last-mentioned case, the cleavage of the ring occurs through a substantially different pathway. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1121–1128, June, 1998.     

Synthesis, structures, and magnetic properties of binuclear carboxylate complexes with NiII and NiIII atoms

The reaction of NiCl₂·6H₂O with Me₃CCOOH and KOH taken in a molar ratio of 1:2:2 in water afforded the nonanuclear antiferromagnetic complex Py₂Ni₂(Me₃CCOOH)₂(OOCCMe₃)₂(μ-OOCCMe₃)₂(μ-OH₂), which apparently contains Ni^II and Ni^III atoms. The complex was isolated by extraction with CH₂Cl₂, benzene, or hexane. The reactions of this complex with pyridine bases (pyridine (Py), 3,4-lutidine (Lut), and nicorandil (Nic)) gave the adducts L₄Ni₂(OOCCMe₃)₂(μ-OOCCMe₃)₂(μ-OH) (L=Py, Lut, or Nic, respectively). According to magnetic measurements, intramolecular ferromagnetic exchange interactions in these adducts are complemented by intermolecular antiferromagnetic interactions. Pyrolysis of the pyridine adduct in air or under an inert atmosphere in xylene yielded the antiferromagnetic complex Py₂Ni₂(Me₃CCOOH)₂(OOCCMe₃)₂(μ-OOCCMe₃)₂(μ-OH₂), which contains Ni^II atoms. The structures of all the complexes synthesized were established by X-ray diffraction analysis. The electronic absorption spectra of these compounds are considered. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 725–738, April, 1998.     

Synthesis, structures and spectroscopic properties of platinum complexes containing orthometalated 2-phenylpyridine

The synthesis, structure and spectroscopy of a series of luminescent orthometalated square planar platinum(II) complexes are reported. Reaction of K₂PtCl₄ with one mole equivalent of 2-phenylpyridine (ppyH) in 2-ethoxyethanol and water (1:1 ratio) resulted in the formation of chloro-bridged dimeric precursor [Pt₂(μ-Cl)₂(ppy)₂], which on further reactions with various anionic one-, two- and three-atom ancillary ligands, having O/N/S donors, yielded mono- and bi-nuclear platinum(II) complexes. Platinum(III) complexes of composition [Pt₂Cl₂(μ-Epy)₂(ppy)₂] have been isolated with pyE⁻ (E = O or S) ligands. These complexes have been characterized by elemental analysis, NMR (¹H, ³¹P, ¹⁹⁵Pt) and absorption spectroscopy. The complexes [Pt₂(μ-N^∩N)₂(ppy)₂] (N^∩N = pyrazole and 3,5-dimethylpyrazole); [Pt(S^∩S)(ppy)] (S^∩S = ethylxanthate and diisopropyldithiophosphate); [Pt₂Cl₂(μ-Epy)₂(ppy)₂] (Epy = 2-pyridinol {Opy} and 2-mercaptopyridine {Spy}) and [PtCl(ppy)(PhNC(Me)NHPh)] have been structurally characterized by X-ray crystallography.     

Syntheses,structures and magnetic properties of Mn(II) containing 3D polymeric networks

Two novel 3D coordination polymers {[Mn(aip)(DMF)]}_n, CPO-9, and {[Mn₃(Hatp)₂(atp)₂](H₂O)₂(DEF)₄}_n CPO-10 (aip = 5-aminoisophthalate, atp = 2-aminoterephthalate, DMF = dimethylformamide, DEF = diethylformamide) have been synthesized by solvothermal methods. Their properties have been studied by single-crystal X-ray diffraction, thermogravimetric analysis, high-temperature powder X-ray diffraction and magnetic susceptibility measurements. The crystal structure of CPO-9 is based on infinite chains of carboxylato-bridged five-coordinated Mn(II) ions that are crosslinked via the aip ligands to form a 3D structure. CPO-10 is based on linear trinuclear building units of carboxylato-bridged octahedral Mn(II) ions that are crosslinked by the atp ligands into a 3D structure. Both compounds have 1D channels that contain solvent molecules. The solvent accessible void volume for CPO-10 is 51.9% of the unit cell volume. For both compounds, however, the solvent molecules cannot be removed without the collapse of the structures into amorphous phases at 250 °C. The magnetic susceptibility measurements indicate antiferromagnetic couplings between the Mn(II) ions in both compounds. The magnetic data have been fitted using theoretical approaches.     

Synthesis and properties of photochromic liquid-crystalline polyacrylates containing a spirooxazine group

The novel photochromic liquid-crystalline polyacrylates containing a spirooxazine group were synthesized. The photochromic polymer containing (4-penta- methyleneoxy)biphenylene moiety at the 5-position of spironaphthoxazine showed nematic phase from 122.9 to 133.8°C. The photochromic polymer containing undeca- methylene instead of pentamethylene showed smectic phase from 93.1 to 169.7°C. On the other hand, the photochromic polymer containing both undecamethylene as a spacer and spironaphthoxazine-bound biphenylene moiety at 9′-position did not show any liquid crystallinity. All spirooxazine-containing liquid-crystalline polymers showed photochromism in the solid state at room temperature. Because the shape of the absorption spectra of the photochromic quenched liquid-crystalline polymer films was almost the same as those of the photochromic amorphous polymer films, the photochromic properties did not depend on the mesophase in the polymers examined. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3513–3522, 1999     

两种由萘二酰亚胺衍生物构建的配位聚合物的合成、结构和光致变色性能

具有可逆颜色变化和适当变色寿命的光致变色材料对于无墨水和可擦除打印技术十分重要。我们将1，4，5，8-萘四羧酸二酐与甲硫氨酸结合，设计了一种基于 1，4，5，8-萘二酰胺(NDI)的桥联有机配体(H₂ncm)，并以 Zn²⁺和 H₂ncm为原料，通过溶剂热反应合成了2种配位聚合物。化合物[Zn(ncm)(H₂O)₄]·2DMF (1)包含1个Zn²⁺、1个ncm^2-配体、4个配位水分子和2个DMF分子。Zn²⁺处于八面体的配位环境中，并通过 ncm^2-配体连接形成链状结构。化合物[Zn₂(ncm)₂(H₂O)₄] (2)包含 2个 Zn²⁺、2个 ncm^2-配体和4个配位水分子。2个Zn²⁺原子通过2个羧基桥联形成双核结构，并进一步通过ncm^2-配体连接形成二维层结构。2显示出从黄色到深棕色的光致变色现象。这种光诱导产生的颜色可以稳定至少3周，但在70 ℃加热时在5 min内即可恢复本来的颜色。我们证明了这种光致变色是源于光照射下NDI·自由基的产生。     

Synthesis, characterization and photochromic studies in film of heterocycle-containing spirooxazines

A series of novel heterocycle-containing spirooxazines have been designed and synthesized, and their photochromic properties were investigated under flash photolysis and continuous irradiation in particular regard to the fatigue resistance, the lifetime of the colored merocyanine form in various solutions and polymers. Especially, the characteristics of two UV-sensitive spirooxazines dispersed polymethylmethacrylate thin-films were extensively studied. Detailed studies showed that general significant shifts in the λ_max of the absorption spectra of the open forms, interesting fatigue resistances and emission fluorescene properties were observed.     

Tetranuclear rhenium chalcogenide cluster complexes with a cubane core. Synthesis,structures, and properties

The results of studies of rhenium chalcogenide cluster complexes with the [Re₄Q₄] cubane core, where Q = S, Se, or Te, are reviewed. Different approaches to the synthesis of these compounds are surveyed and their properties and structures are considered. Substitution reactions in the cluster core and replacements of terminal ligands are discussed. The formation of polymers consisting of the tetranuclear rhenium chalcogenide cyanide clusters as structural building blocks is considered.     

Synthesis, properties, and the crystal structure of the complex Cp2Yb(DAD)

The diazadiene complex of trivalent ytterbium, Cp₂Yb(DAD) (1) (DAD=Bu^t−N=CH−CH=N−Bu^t) was prepared according to three different procedures, namely, by oxidation of Cp₂Yb(THF)₂ with diazadiene in THF, by the reaction of Cp₂YbCl with DAD²⁻Na⁺ ₂ taken in a ratio of 2∶1, and by the reaction of Cp₂YbCl(THF) with DAD²⁻Na⁺ ₂ taken in a ratio of 1∶1. Complex1 was characterized by microanalysis, IR spectroscopy, magnetochemistry, and X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 384–386, February, 1999.     

两种由萘二酰亚胺衍生物构建的配位聚合物的合成、结构和光致变色性能

具有可逆颜色变化和适当变色寿命的光致变色材料对于无墨水和可擦除打印技术十分重要。我们将1,4,5,8-萘四羧酸二酐与甲硫氨酸结合,设计了一种基于1,4,5,8-萘二酰胺（NDI）的桥联有机配体（H₂ncm）,并以Zn²⁺和H₂ncm为原料,通过溶剂热反应合成了2种配位聚合物。化合物[Zn（ncm）（H₂O）₄]·2DMF （1）包含1个Zn²⁺、1个ncm^2-配体、4个配位水分子和2个DMF分子。Zn²⁺处于八面体的配位环境中,并通过ncm^2-配体连接形成链状结构。化合物[Zn₂（ncm）₂（H₂O）₄] （2）包含2个Zn²⁺、2个ncm^2-配体和4个配位水分子。2个Zn²⁺原子通过2个羧基桥联形成双核结构,并进一步通过ncm^2-配体连接形成二维层结构。2显示出从黄色到深棕色的光致变色现象。这种光诱导产生的颜色可以稳定至少3周,但在70 ℃加热时在5 min内即可恢复本来的颜色。我们证明了这种光致变色是源于光照射下NDI·自由基的产生。     

Synthesis and structures of silicon-, germanium-, and tin-containing imido-alkyl molybdenum complexes (ArN)2Mo(CH2EMe3)2 (E = Si, Ge, Sn)

New silicon-, germanium-, and tin-containing imido-alkyl molybdenum complexes (ArN)₂Mo(CH₂EMe₃)₂ (Ar is 2,6-diisopropylphenyl; E = Si (1), Ge (2), Sn (3)) were prepared in the crystalline state in 58–66% yields by the reactions of the (ArN)₂MoCl₂(DME) complex with alkyllithium derivatives Me₃ECH₂Li (E = Si or Ge) or the Grignard reagents Me₃ECH₂MgCl (E = Ge or Sn). The structures of complexes 1–3 and the known analog (ArN)₂Mo(CH₂Bu^t)₂ (4) were established by X-ray diffraction analysis. Complexes 1–3 were found to be isostructural. The coordination environment about the Mo atom can be described as a distorted tetrahedron. Complex 4 has a similar structure. The Mo-C distance tends to decrease with increasing electron donating ability of the EMe₃ group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 597–600, March, 2005.     

Synthesis, characterization and dielectric properties of new unidimensional quaternary tellurites: LaTeNbO6, La4Te6Nb2O23, and La4Te6Ta2O23

Three new tellurites, LaTeNbO₆ and La₄Te₆M₂O₂₃ (M=Nb or Ta) have been synthesized, as bulk phase powders and crystals, by using La₂O₃, Nb₂O₅ (or Ta₂O₅), and TeO₂ as reagents. The structures of LaTeNbO₆ and La₄Te₆Ta₂O₂₃ were determined by single crystal X-ray diffraction. LaTeNbO₆ consists of one-dimensional corner-linked chains of NbO₆ octahedra that are connected by TeO₃ polyhedra. La₄Te₆M₂O₂₃ (M=Nb or Ta) is composed of corner-linked chains of MO₆ octahedra that are also connected by TeO₄ and two TeO₃ polyhedra. In all of the reported materials, Te⁴⁺ is in an asymmetric coordination environment attributable to its stereo-active lone-pair. Infrared, thermogravimetric, and dielectric analyses are also presented. Crystallographic information: LaTeNbO₆, triclinic, space group P−1, a=6.7842(6) Å, b=7.4473(6) Å, c=10.7519(9) Å, α=79.6490(10)°, β=76.920(2)°, γ=89.923(2)°, Z=4; La₄Te₆Ta₂O₂₃, monoclinic, space group C2/c, a=23.4676(17) Å, b=12.1291(9) Å, c=7.6416(6) Å, β=101.2580(10)°, Z=4.