Synthesis and spectral properties of unsymmetrical phthalocyanines from 3,6-dioctyloxyphthalonitrile and 3,4,5,6-tetrachlorophthalonitrile

The random condensation of 3,6-dioctyloxyphthalonitrile (component A) with 3,4,5,6-tetrachlorophthalonitrile (component B) results in unsymmetrical phthalocyanines of A₃B, ABAB, and AABB types. Their spectral properties were studied.     

Synthesis and spectral properties of new planar binuclear phthalocyanines sharing the benzene ring

New planar binuclear phthalocyanines sharing the benzene ring were synthesized and their spectral properties were studied. Intense absorption in the near-IR region (∼850 nm) was observed for the first time. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1112–1115, July, 2006.     

Synthesis and spectral properties of tetraphenoxysubstituted erbium phthalocyanines containing peripheral phenyl and cyclohexyl fragments

Russian Chemical Bulletin - The synthesis of peripherally and non-peripherally substituted erbium phthalocyanines with cyclohexylphenoxyl or phenylphenoxyl fragments by the template condensation of...     

Dendritic phthalocyanines: synthesis,photophysical properties,and aggregation behavior

This mini-account describes our recent effort to exploit dendritic phthalocyanines, focusing on their photophysical properties and aggregation behavior in water and in microheterogeneous media. Two series of dendritic phthalocyanines have been prepared. The ones with terminal ester functionalities are non-aggregated in common organic solvents, exhibiting an intramolecular singlet-singlet energy transfer from the excited aryl-containing dendrons to the phthalocyanine core. The other series contain terminal carboxylate groups of which the aggregation tendency in water decreases as the size of the dendron increases. The lower-generation analogues are susceptible to surfactants, in particular the cationic n-hexadecyltrimethylammonium bromide (CTAB), and poly(ethylene oxide) (PEO), which are very effective to disrupt the molecular aggregation of phthalocyanines. The interactions have been monitored by absorption and fluorescence spectroscopy together with laser light scattering. The photophysical properties of the dendrimer/PEO complexes have also been studied by transient spectroscopy. To cite this article: D.K.P. Ng, C. R. Chimie 6 (2003).     

Highly selective synthesis of unsymmetrical phthalocyanines from 3,6-Bis(hexadecyloxy)phthalonitrile and their spectral characteristics

3,6-Bis(hexadecyloxy)phthalonitrile (A) reacted with 3-nitrophthalonitrile or 4-bromophthalonitrile (B) to produce AABB and ABAB type phthalocyanines with high selectivity. Spectral properties of the synthesized compounds were studied.     

Facile preparation,spectral property and application of Ag/ZnO nanocomposites

Research on Chemical Intermediates - In this paper, a one-pot and sustainable method for the preparation of Ag/ZnO nanocomposites in green polyethylene glycol-200 (PEG-200) was reported with silver...     

Sandwich complexes of lutetium with tetraanthraquinoneporphyrazine and asymmetric alkoxy-substituted phthalocyanines. Preparation and spectral properties

Interaction of 3,6-di(hexadecyloxy)phthalonitrile with tetrachlorophthalonitrile and lutetium chloride in alcoholic medium yields lutetium complexes with asymmetric phthalocyanines. Their heating with dinitrile of anthraquinone-2,3-dicarboxylic acid gives the sandwich complexes containing fragments of tetraanthraquinoneporphyrazine and asymmetric phthalocyanines; their spectral properties has been studied.     

Synthesis and solvent effects on the electronic absorption and fluorescence spectral properties of substituted zinc phthalocyanines

The synthesis and spectroscopic properties of the following tetra- and octa-substituted aryloxy zinc(II) phthalocyanines are reported for the first time: 1,(4)-(tetrabenzyloxyphenoxyphthalocyaninato) zinc(II) (7); 2,(3)-(tetrabenzyloxyphenoxyphthalocyaninato) zinc(II) (8); 2,3-(octabenzyloxyphenoxyphthalocyaninato) zinc(II) (9). The new compounds have been characterized by elemental analysis, IR, ¹H NMR spectroscopy and electronic spectroscopy. Spectroscopic properties of these compounds were investigated in different solvents. Protonation of non-peripherally substituted complex 7 resulted in the splitting and red-shifting of the Q-band. The peripherally substituted derivatives 8 and 9, did not show the split in the Q-band. Fluorescence spectra of the derivatives show Stokes shifts typical of MPc complexes.     

Sandwich double-decker lanthanide(III) "intracavity" complexes based on clamshell-type phthalocyanine ligands: synthesis, spectral, electrochemical, and spectroelectrochemical investigations

Phthalocyanine compounds of novel type based on a bridged bis-ligand, denoted "intracavity" complexes, have been prepared. Complexation of clamshell ligand 1,1'-[benzene-1,2-diylbis(methanediyloxy)]bis[9(10),16(17),23(24)-tri-tert-butylphthalocyanine] ((clam,tBu)Pc(2)H(4), 1) with lanthanide(III) salts [Ln(acac)(3)]?n?H(2)O (Ln = Eu, Dy, Lu; acetylacetonate) led to formation of double-deckers (clam,tBu)Pc(2)Ln (2?a-c). Formation of high molecular weight oligophthalocyanine complexes was demonstrated as well. The presence of an intramolecular covalent bridge affecting the relative arrangement of macrocycles was shown to result in specific physicochemical properties. A combination of UV/Vis/NIR and NMR spectroscopy, MALDI-TOF mass-spectrometry, cyclic voltammetry, and spectroelectrochemistry provided unambiguous characterization of the freshly prepared bis-phthalocyanines, and also revealed intrinsic peculiarities in the structure-property relationship, which were supported by theoretical calculations. Unexpected NMR activity of the paramagnetic dysprosium complex 2?b in the neutral π-radical form was observed and examined as well.     

Synthesis,characterization and electrochemical properties of new phthalocyanines

The chemical synthesis and characterization with spectroscopic and electrochemical properties of [bis(4-fluorophenyl)-methoxy]-substituted metallo-phthalocyanines were reported for the first time. The new phthalocyanines have been characterized by elemental analysis, UV-Vis, FT-IR, and mass spectroscopies. The aggregation behavior of the phthalocyanine compounds was investigated in different solvents and concentrations. It is found that the fluoro substituents of peripherally Co and Cu complexes are examined and induce a shift to the redox processes toward the negative potentials and formed more reversible processes. Metal-based reduction and oxidation reactions were obtained for the Co(II) complex, whereas Cu(II) complexes exhibited Pc-ring-based electron-transfer reactions. The voltammetric measurements supported the proposed structure of the complexes.     

Syntheses and properties of octa-, tetra-, and di-hydroxy-substituted phthalocyanines

The synthesis and photophysical properties of a new series of zinc(II) phthalocyanines (ZnPcs) bearing multiple hydroxy and tert-butyl groups are reported. The X-ray structures of two phthalonitriles and one ZnPc are presented. All hydroxy-substituted ZnPcs show low fluorescence quantum yields in DMSO and complete fluorescence quenching in aqueous solutions, but high singlet oxygen quantum yields in DMSO (0.2-0.7). Our results suggest that the tetra- and octa-hydroxy ZnPcs might find application as photosensitizers in the PDT treatment of cancer.     

The preparation of ferrocenedithiocarboxylic acid derivatives and their spectral properties

Ferrocenedithiocarboxylic acid and various derivatives have been prepared and characterized. The molecular extinction coefficients for the n → π transition of the thiocarbonyl group in the visible spectra of these derivatives are 10–15 fold greater than expected for aromatic dithio acids.     

Linear- and angular-shaped naphthodithiophenes: selective synthesis, properties, and application to organic field-effect transistors

A straightforward synthetic approach that exploits linear- and angular-shaped naphthodithiophenes (NDTs) being potential as new core structures for organic semiconductors is described. The newly established synthetic procedure involves two important steps; one is the chemoselective Sonogashira coupling reaction on the trifluoromethanesulfonyloxy site over the bromine site enabling selective formation of o-bromoethynylbenzene substructures on the naphthalene core, and the other is a facile ring closing reaction of fused-thiophene rings from the o-bromoethynylbenzene substructures. As a result, three isomeric NDTs, naphtho[2,3-b:6,7-b']dithiophene, naphtho[2,3-b:7,6-b']dithiophenes, and naphtho[2,1-b:6,5-b']dithiophene, are selectively synthesized. Electrochemical and optical measurements of the parent NDTs indicated that the shape of the molecules plays an important role in determining the electronic structure of the compounds; the linear-shaped NDTs formally isoelectronic with naphthacene have lower oxidation potentials and more red-shifted absorption bands than those of the angular-shaped NDTs isoelectronic with chrysene. On the contrary, the performance of the thin-film-based field-effect transistors (FETs) using the dioctyl or diphenyl derivatives were much influenced by the symmetry of the molecules; centrosymmetric derivatives tend to give higher mobility (up to 1.5 cm(2) V(-1) s(-1)) than axisymmetric ones (～0.06 cm(2) V(-1) s(-1)), implying that the intermolecular orbital overlap in the solid state is influenced by the symmetry of the molecules. These results indicate that the present NDT cores, in particular the linear-shaped, centrosymmetric naphtho[2,3-b:6,7-b']dithiophene, are promising building blocks for the development of organic semiconducting materials.     

Preparation,chemical modification and absorption properties of various phthalocyanines

A series of phthalocyanines were prepared from phthalodinitrile and corresponding metal salts by means of the ‘solvent’ methods. Some experiments were also conducted in the absence of a solvent in a ‘solvent-free’ process from phthalanhydride, urea and metal chlorides. All of the prepared phthalocyanines were modified by the incorporation of desirable functional groups in order to transform the virtually insoluble phthalocyanine skeleton into more soluble forms. Derivatives soluble in polar media were prepared by means of sulphonation, while those soluble in non-polar media were produced by chlorosulphonation with the subsequent condensation of prepared sulphochlorides with primary alkyl amines.     

Synthesis, photophysical and photochemical properties of substituted zinc phthalocyanines

The synthesis, photophysical and photochemical properties of the 4-({3,4,5-tris-[2-(2-ethoxyethoxy)ethyloxy]benzyl}oxy) and 4-({3,4,5-tris-[2-(2-ethoxyethoxy)ethyloxy]benzyl}thio) zinc(ii) phthalocyanines are reported for the first time. The new compounds have been characterized by elemental analysis, IR, (1)H and (13)C NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for photodegradation, singlet oxygen, fluorescence and triplet excited state quantum yields, and triplet state and fluorescence lifetimes of these compounds in dimethylsulfoxide (DMSO). The fluorescence of the complexes was quenched by benzoquinone (BQ). The effects of the substitution on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (6, 7 and 8) are also reported. Photophysical and photochemical properties of phthalocyanine complexes are very useful for PDT applications. The substituted Zn(II) phthalocyanines showed high triplet and singlet oxygen quantum yields. High singlet oxygen quantum yields are very important for Type II mechanism. Thus, these complexes show potential as Type II photosensitizers.     

Azabicycloalkenes as synthetic intermediates: application to the preparation of diazabicycloalkane scaffolds

[reaction: see text] A general method to synthesize bicyclic dipeptide mimetics is reported. Key intermediates are azabicycloalkenes 9 and 17, which are prepared via Diels-Alder reactions and subsequent mild deprotection. These unsaturated bicyclic heterocycles are versatile intermediates for different dipeptide mimetics of the aza- and diazabicycloalkane type, which is demonstrated by the synthesis of diazabicycloalkanes 11 and 19 in only 3-6 steps and good overall yield.     

Synthesis and spectral characteristics of cyclohexylmethoxy-substituted phthalocyanines of rare-earth elements

New symmetrical metal complexes of the rare-earth element phthalocyanines were synthesized by the reaction of 4,5-bis(cyclohexylmethoxy)phthalonitrile, obtained for the first time, with the rare-earth element salts, as well as starting from the corresponding free phthalocyanine. A correlation between method of the synthesis and the reaction product compositions was studied. Structures of the complexes obtained were confirmed by mass spectrometry, X-ray crystallography, and electronic absorption spectroscopy. All the metal complexes are well soluble in organic solvents. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2343–2349, December, 2007.     

盐酸甲胺三氧铬的制备及其α,β-不饱和醇的选择性氧化

本文报道盐酸甲胺三氧铬(3)的制备方法,并在DMF中作了一些醇的氧化试验,试验结果表:3其有很高的氧化选择性,它能顺利地将多种α,β- 不饱和醇氧化成相应的醛或酮;而在相同条件下,不氧化饱和醇, 并且在一定条件下可以氧化分子内的苄醇羟基而不氧化同一分子中的酚羟基和饱和醇羟基。3在DMF中使用时, 没有明显的酸性,可以用于氧化对酸敏感的化合物,而且它制备简单,使用条件温和,是一种优良的高选择性氧化剂。     

The preparation, properties and application of carbon fibers for SPME

The conditions of preparation of new types of carbon fibers for solid phase micro extraction (SPME) prepared by methylene chloride pyrolysis (at 600 °C) on the quartz fiber (100 μm) as well as by supporting synthetic active carbon (prepared especially for this purposes) supported in a special epoxide-acrylic polymer is described. The properties of such carbon fibers for SPME were defined by determination of the partition coefficient of the tested substances (i.e., benzene, toluene, xylenes, trichloromethane and tetrachloromethane) and by the microscopic investigations with the application of the optical and scanning electron microscope.

The obtained carbon SPME fibers were applied to the analysis of some volatile organic compounds from its aqueous matrix. During chromatographic GC test, at the investigated SPME carbon fibers, we obtained different but mostly high partition coefficients for the determined compounds (Kfs from 120 for trichloromethane up to 11,500 for tetrachloromethane).

Owing to the high partition coefficients of the studied substances obtained on carbon fibers, it was possible to do the analysis of organic substances occurring in trace amounts in different matrices. In this paper, we present the analysis of BTX contents in the petrol analyzed with the application carbonized with CH₂Cl₂ SPME fiber (C1NM) and a headspace over the petrol sample (concentration of each BTX g/dm³).