Synthesis and electrochemical,in situ spectroelectrochemical,electrical and gas sensing properties of ball-type homo- and hetero-dinuclear phthalocyanines with four [1a,8b-dihydronaphtho[b]naphthofuro[3,2-d]furan-7,10-diyl] bridges

The new mono-nuclear Fe^II 2 and ball-type homo-dinuclear Fe^II–Fe^II 3 phthalocyanines have been synthesized from the corresponding 4,4′-(1a,8b-dihydronaphtho[b]naphthofuro[3,2-d]-furan-7,10-diyl)bis(oxy)diphthalonitrile 1 while ball-type hetero-dinuclear Fe^II–Co^II phthalocyanine 4 was synthesized from 2. The compounds have been characterized by elemental analysis, UV–vis, IR and MALDI-TOF-mass spectroscopies. The redox behaviours of the complexes were identified by controlled-potential coulometry, cyclic voltammetry and differential pulse voltammetry measurements on Pt in dimethylsulfoxide containing tetrabutylammonium perchlorate. The assignments of the redox processes and the understanding of the interactions between the metal phthalocyanine units in 3 and 4 were achieved by the combined evaluation of the voltammetric and in situ spectroelectrochemical outcomes. Complex 3 showed ring-based mixed-valence behaviour as a result of the considerable interaction between the phthalocyanine rings. On the other hand, the interactions between the two metal phthalocyanine units of 4 were found to be much weaker than those in 3. The potential application of molecular organic semiconductors needs the control adjustment of conductivity. Ac and dc conductivity measurements were performed with the applied external electric filed. At high frequency, the conduction follows the universal power law and conduction mechanism can be explained by classical hopping barriers mechanism for the system.     

Synthesis,photophysics, photochemistry and fluorescence quenching studies on highly soluble substituted oxo-titanium(IV) phthalocyanine complexes

The synthesis, photophysical and photochemical properties of soluble 3,4-(methylendioxy)-phenoxy substituted oxo-titanium(IV) phthalocyanines (4–6) are reported for the first time. The new compounds have been characterized by elemental analysis, FT-IR, ¹H NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for fluorescence lifetimes and fluorescence, photodegradation and singlet oxygen quantum yields, of these compounds in dimethylsulfoxide (DMSO) and toluene. The effects of the position of the substituents and solvent effect on the photophysical and photochemical parameters of the oxo-titanium(IV) phthalocyanines (4–6) are also reported. The fluorescence of the substituted oxo-titanium(IV) phthalocyanine complexes (4–6) is effectively quenched by 1,4-benzoquinone (BQ) in both DMSO and toluene.     

Synthesis, photophysical and photochemical properties of crown ether substituted zinc phthalocyanines

The photophysical and photochemical properties of the tetra- and octa-12-crown-4-substituted zinc (II) phthalocyanines are reported for the first time in the scope of this work. The new compounds have been characterized by elemental analysis, IR, ¹H and ¹³C NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for photodegradation, singlet oxygen and fluorescence quantum yields, and fluorescence lifetimes of these compounds in dimethylsulphoxide (DMSO). Photophysical and photochemical properties of phthalocyanine complexes are very useful for photodynamic therapy (PDT) applications. The effects of the substituents on the photophysical and photochemical parameters of the zinc (II) phthalocyanines (5, 6 and 7) are also reported. The singlet oxygen quantum yields (Φ_Δ) ranged from 0.48 to 0.78 are indicating the potential of the complexes as photosensitizers in applications of PDT. The fluorescences of the substituted ZnPc complexes are effectively quenched by benzoquinone (BQ).     

Synthesis,crystal structure and electrical properties of [Pd(dmit)2]2− and [Pd(dmit)2]0.5− anion complexes with 2-dimethylamino-1,3-dithiolanylium as counter cation

The synthesis, structural characterization and electrical conductivity measurement of [MDA]₂[Pd(dmit)₂] (1 and [MDA] [Pd(dmit)₂]₂ (2) (MDA = 2-dimethylamino-1,3-dithiolanylium, dmit = 1,3-dithiole-2-thione-4,5-dithiolate) are reported. Complex 1 consists of two Pd(dmit)₂ anions and four MDA cations in the unit cell and the anions are separated by cations in the crystal; the conductivity is about 10⁻⁷ S cm⁻¹. The structure of complex 2 is made of stacked Pd(dmit)₂ dimers. The modes of intra- and inter-dimer molecular overlapping are both of slide-away types. Pd atoms deviate from planes formed by four ligand S atoms 0.07 Å apart to approach each other. Room-temperature conductivity is 10–70 S cm⁻¹. Temperature-dependent conductivity measurement of this compound indicated that it is a semiconductor with a low activation energy (0.043 eV).     

The first BDH-TTP radical cation salts with mercuric counterions, κ-(BDH-TTP)4[Hg(SCN)4]·C6H5NO2 and α′-(BDH-TTP)6[Hg(SCN)3][Hg(SCN)4]

Two new radical cation salts of the non-TTF containing donor BDH-TTP with the thiocyanatomercurate anions were synthesized. The κ-(BDH-TTP)₄[Hg(SCN)₄]·C₆H₅NO₂ (1) and α′-(BDH-TTP)₆[Hg(SCN)₃][Hg(SCN)₄] (2) salts were characterized by single crystal X-ray diffraction, electrical resistance measurements and electronic band structure calculations. Both salts have a layered structure in which the BDH-TTP layers of κ- or α′-type alternate with anionic sheets. The anionic layers of 1 contain the counterion [Hg(SCN)₄]²⁻ and the nitrobenzene molecule which are statistically disordered. Salt 2 contains two different layers (although both of the α′-type) of the organic donors, a somewhat unusual fact in organic conductors. The anion layers of 2 consist of polymeric chains built up from a combination of the two different anions, [Hg(SCN)₃]¹⁻ and [Hg(SCN)₄]²⁻. Salt 1 shows a metallic behavior down to helium temperatures whereas salt 2 exhibits two-phase transitions in the temperature range 295–8 K.     

Comparison of photophysicochemical properties of hexaphenoxycyclotriphosphazenyl-substituted metal-free,mono- and bis-lutetium phthalocyanines

The aim of this study is to compare the photophysicochemical properties of hexaphenoxycyclotriphosphazenyl-substituted metal-free (1), mono-(phthalocyaninato) lutetium(III) (2) [Lu^III(AcO)(Pc)] (Pc = phthalocyaninato, AcO = acetate) and bis-(phthalocyaninato) lutetium(III) (3) [Lu^IIIPc₂]. The synthesis and characterization (using the elemental analysis, mass spectrometry, IR, ¹H, and ³¹P NMR and UV–vis spectroscopy) of new compounds (2, 3) are described in this study. The electronic absorption and fluorescence spectral properties of compounds 1–3 are investigated. Photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yields) measurements are also studied on hexaphenoxycyclotriphosphazenyl-appended metal-free, mono- and bis-lutetium phthalocyanines in dimethylsulfoxide (DMSO). Photophysical and photochemical properties of phthalocyanines are very useful for photodynamic therapy (PDT) applications. Singlet oxygen quantum yields (Φ_Δ) give an indication of the potential of the complexes as photosensitizers in PDT applications. Hexaphenoxycyclotriphosphazenyl-substituted mono-(phthalocyaninato) lutetium(III) complex (2) gave good singlet oxygen quantum yield (0.66) in DMSO. Thus, this complex shows potential as Type II photosensitizer for PDT of cancer.     

Metal ion sensing functional mono and double-decker lanthanide phthalocyanines: Synthesis,characterization and electrical properties

We report, in this study, the preparation, physical characterization metal ion sensing properties of peripherally functionalized ionophore ligand, 4,5-bis(6-hydroxyhexylthio)-1,2-dicyanobenzene (1) and its mono 2,3,7,8,12,13,17,18-octakis(6-hydroxyhexylthio)phthalocyaninatometal (II) {M = Zn^II (2), Cu^II (3)} and double-decker lanthanide bis-phthalocyanines, {([4,5,4′,5′ 4″,5″,4?,5?]-tetrakis-(6-hydroxyhexylthio)phthalocyaninatolanthanium(III)}){M[Pc(S–C₆H₁₃OH)₄]₂} {M = Eu^III (4), Yb^III (5), and Lu^III (6)}. All benzenes on phthalocyanines are functionalized with hydroxyhexylsulfanyl moieties for potential use as soft metal ion binding, such as Ag⁺ and Pd²⁺. The temperature dependence of the dc and ac conduction properties of 4, 5 and 6 thin films have been investigated in the frequency range of 40–10⁵ Hz and temperature range 290–436 K. The dc results showed an activated conductivity dependence on temperature for all films. Obtained data reveal that ac conductivity obeys the relation σ_ac(ω) = Aω^s and exponent is found to decrease by increasing temperature. The data obtained results were compared with the prediction of the Quantum Mechanical Tunelling (QMT) and Correlated Barrier Hopping (CBH) models. The analysis showed that the CBH model is the dominant conduction mechanism for the electron transport in the films. The new synthesized compounds have been characterized by elemental analysis, FTIR, ¹H and ¹³C NMR, MS, UV–vis and EPR spectral data.     

Two Cd(II) coordination polymers based on asymmetrical Schiff-base ligand with five- and six-membered N-containing heterocyclic rings: Synthesis,crystal structures and luminescent properties

Two cadmium inorganic–organic hybrid coordination polymers [CdL(SCN)₂]_n (1) and [CdLI₂]_n (2), have been synthesized and characterized by IR spectroscopy, elemental analysis, XRPD, thermogravimetric (TG) analyses and X-ray crystallography, where L is 4-(pyridine-4-yl)methyleneamino-1,2,4-triazole. Asymmetrical Schiff-base ligand L acts as a bidentate bridging ligand to bind two Cd(II) centers through two terminal N_triazolyl and N_pyridyl donors in polymers 1 and 2. Polymer 1 displays a new 3D inorganic–organic hybrid network generated through the coordination interactions between Cd-(1,3-μ-SCN⁻) 2D inorganic sheets and bidentate bridging ligands. The structure of polymer 2 is a 3D chiral supramolecular framework which contains helical chains on 2₁ axis. Each Cd(II) center is coordinated by two ligands and two I⁻ donors to attain a distorted tetrahedral environment. The luminescent properties of polymers 1 and 2 were investigated in the solid state at room temperature.     

Synthesis and characterization of poly[(R)-(−) and (S)-(+)-3-(1′-pyrrolyl)propyl-N-(3″,5″-dinitrobenzoyl)-α-phenylglycinate]s as chiral oligomers of pyrrole

Chiral polypyrrole oligomers were prepared from (R)-(?) (1) and (S)-(+)-3-(1′-pyrrolyl)propyl-N-(3″,5″-dinitrobenzoyl)-α-phenylglycinate (2) by oxidative polymerization in the presence of FeCl₃ as an oxidant. The new polymers were characterized by ¹H NMR, FTIR and UV–vis (λ_máx = 251 nm). TGA analyses of the corresponding polymers, poly1 and poly2, demonstrate an excellent thermal stability up to 204 °C, followed by two consecutive weight losses at higher temperatures. Relative number-average molecular weights of about 1.4 × 10³ and 2.3 × 10³, for poly1 and poly2, respectively, were measured by SEC, corresponding to oligomeric chains. Specific optical rotation measurements (c 0.1, THF) for poly1 [α]_D²⁰ = ?44 and poly2 ([α]_D²⁰ = +44) suggest that chirality is retained during the polymerization. Transversal section analysis of SEM images indicates the materials isolated right after the synthesis is highly porous.     

Highly conjugated acrylate-functionalized polythiophenes from anodic coupling of thiophene- and bithiophene-hexyl acrylates

Anodic coupling of thiophene- (1) and cyclopentadithiophene- (2) hexyl acrylates in acetonitrile to polythiophenes is reported. The resulting polymers have been characterized by cyclic voltammetry, UV–vis and FTIR spectroscopy and in-situ conductivity. The produced polythiophene films, for which FTIR analysis show that the acrylate moiety is kept unchanged, display high conjugation lengths (λ_max=520 (1) and 600 (2) nm) and conductivities (20 (1) and 100 (2) S cm⁻¹).     

Preparation of silver nanostructure from silver(I) coordination polymer and fabrication of nano silver(I) bromide by reverse micelles technique

A new one-dimensional silver(I) coordination polymer, [Ag(μ-bpfb)(NO₃)]_n (1); bpfb = N,N′-bis(4-pyridylformamide)-1,4-benzene, has been synthesized and characterized by IR, ¹H NMR and ¹³C NMR spectroscopy. The single crystal X-ray data show that the silver(I) 1D coordination polymer grows into a three-dimensional network by hydrogen bonding and π–π stacking interactions. Compound 1 with nanorod morphology was also prepared by sonochemical method. The cetyltrimethylammonium bromide (CTAB) as a cationic surfactant was used in reverse micelles technique to obtain spongy silver(I) bromide nanoparticles from compound 1. Also, different silver nanoparticles have been prepared via direct calcination at 673 K and thermal decomposition in oleic acid from compound 1. The nanostructures of [Ag(μ-bpfb)(NO₃)]_n (1), silver and silver(I) bromide were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDAX) analysis. Thermal stability of compound 1 in both bulk and nano-sized form was studied by thermal gravimetric (TG) and differential thermal (DT) analyses.     

Synthesis and properties of bridged phthalocyaninatoiron(II) complexes with bidentate aliphatic isocyanides

Phthalocyaninatoiron(II) (PcFe) was reacted with several aliphatic 5, 10–13, alicyclic 14, and aromatic isocyanides 3, 4 to form monomeric 15–17 and bridged oligomeric complexes 18–22. The syntheses of the isocyanides from the corresponding amines are described. All the products were characterized by spectroscopic methods. The coordination behaviour of the isocyanides based on their spectroscopic properties is discussed. The oligomers 18–22 show conductivities in the low semiconducting region, but by doping with iodine conductivities between 10⁻⁵ and 10⁻² S/cm were obtained.     

The synthesis of low crystallinity polyacetylene from the precursor polymer polybenzvalene

The synthesis and properties of the conductive polymer precursor polybenzvalene (PBV) and its conversion to polyacetylene (PA) are presented. PBV was synthesized by ring-opening metathesis polymerization (ROMP) of benzvalene (BV) with non-Lewis acidic tungsten alkylidene catalysts. Treatment of PBV with solutions of HgCl₂, HgBr₂, ZnI₂ and AgBF₄ results in a CC bond rearrangement, and produces polyacetylene PA. The PA films produced with HgCl₂ displayed the highest conductivities and the best mechanical properties. The PA produced was of low crystallinity and upon treatment with I₂ exhibited conductivities of 1 Ω⁻¹cm⁻¹. Oriented PA was produced by stretching the PBV and converting it to PA. With I₂ doping, the oriented PA (l/l₀=6) displayed a conductivity of 49 Ω⁻¹cm⁻¹.     

Investigation of crown-containing styrylthiophene derivatives which are optically and electrochemically sensitive to the presence of metal cations

The analysis of complex formation of crown-containing styryl and bisstyryl thiophene derivatives with alkaline earth metal cations and the investigation of optical and electrochemical responses induced by metal cations are reported. The monostyryl derivative forms weakly fluorescent inclusion complexes with Mg²⁺ cations and weakly fluorescent anti-sandwich complex with Ba²⁺ cations. In case of bisstyryl thiophene compounds the Mg²⁺ complexes are fluorescent, whereas, the sandwich complex with composition (1b)₂·(Ba²⁺)₂ or (1b)₂·(Ba²⁺)₃ are weakly fluorescent. The results of the investigations showed that the crown-containing mono- and bisstyryl thiophene derivatives are optically and electrochemically sensitive to the presence of metal cations.     

Copper(I) coordination ability of the outer S-position isomer of EDT-DMT-TTF (D1): crystal structure of (D1)2Cu2Br4,2CH2Cl2; structural correlation with the (D1)2Cu2Br6 copper(II) salt

The (D1)₂Cu₂Br₄,2CH₂Cl₂ (1) and (D1)₂Cu₂Br₆ (2) radical cation salts, where D1 is the outer S-position isomer of ethylenedithiodimethylthiotetrathiafulvalene (EDT-DMT-TTF), have been synthesized and their X-ray crystal structures have been solved. The molecular structure of 1 is built up from (D1–Cu₂Br₄–D1) metal complexes. Each copper(I) atom is coordinated to a sulfur atom of the D1 disulfide bridge through a σ-type dative bond. Consequently, Cu₂Br₄ part is located between two organic molecules which are approximately plane and parallel to each other. In compound 2, (Cu₂Br₆)²⁻ anions, in which copper atoms are at the +2 oxidation state, also lie between two oxidized donors. In both resulting structures, the D1–Cu₂Br_x–D1 parts (x=4 for 1, x=6 for 2) are stacking in order to form columns containing dimerized (D1⁺)₂ units.     

Synthesis and characterization of a series of bis(dimethyl-n-octylsilyl)oligothiophenes for organic thin film transistor applications

A series of bis-dimethyl-n-octylsilyl end-capped oligothiophenes consisting of two to six thiophene units has been synthesized and characterized to develop novel organic semiconductor materials. The UV–vis spectral data indicate that these silyl end-capped oligothiophenes have longer conjugation lengths as evidenced by the higher λ_max values than the corresponding unsubstituted thiophene oligomers. The thermal analyses indicate that the bis-silylated oligothiophenes show lower melting point (DSi-4T = 80 °C; DSi-5T = 115 °C; DSi-6T = 182 °C) than the corresponding dialkylated thiophene oligomers by 100 °C and hexamer DSi-6T exhibits a liquid crystalline mesophase at 143 °C. The α,ω-bis(dimethyl-n-octylsilyl)oligothiophenes (DSi-6T) have a remarkably high solubility in chloroform which are comparable to the corresponding α,ω-dihexyloligothiophenes. The remarkably increased solubility by these silyl end groups leads bis-silylated oligothiophenes to be applicable to solution processable devices for thin film transisitor (TFT) by utilizing a spin-coating technique. α,ω-Bis(dimethyl-n-octylsilyl)sexithiophene can be deposited as active semiconducting layer in thin film transistors, either by vacuum evaporation or by spin-coating. A high charge-carrier mobility has been obtained for both deposition techniques, μ = 4.6 × 10⁻² and 1.4 × 10⁻² cm² V⁻¹ s⁻¹, respectively.     

Synthesis,electrochemistry, spectroelectrochemistry and electrocolorimetry of phthalocyanine–anthraquinone hybrids

The tetra substituted metallophthalocyanines 2 and 3, soluble in common organic solvents, bearing four 2-(9,10-dioxo-9,10-dihydro-anthracen-2-yl-methyl)-malonic acid diethyl ester functionalities were synthesized from the corresponding phthalodinitrile 1 and divalent metal salts at 170 °C in fused state. Reaction of with manganese (2+) acetate in n-pentanol led to the manganese (3+) phthalocyanine 4. Furthermore, the unsymmetrical copper phthalocyanine 5 containing one 2-(9,10-dioxo-9,10-dihydro-anthracen-2-yl-methyl)-malonic acid diethyl ester moiety was synthesized using a statistical approach. The new compounds were characterized by elemental analysis together with FT-IR, ¹H-NMR, ¹³C-NMR, and UV–vis spectroscopy and via mass spectrometric analysis. The electrochemical, in situ spectroelectrochemical, and in situ electrocolorimetric measurements represent that while MPcs give common ring-based and/or metal-based electron transfer processes, these processes were considerably affected with the redox processes of the AQ units attached to the phthalocyanine ring. At the same time attachments of the AQ units to the phthalocyanine rings improve the reversibility of the AQ units due to the electron donor–acceptor interaction between the AQ units and phthalocyanine ring. The AQ units also alter the color states of the phthalocyanines.     

Synthesis,characterization, and electrical,electrochemical and gas sensing properties of a novel cyclic borazine derivative containing three phthalocyaninato zinc(II) macrocycles

A novel borazine derivative of trinuclear phthalocyanine has been prepared by following the multistep reactions of unsymmetrically substituted phthalocyanines. 4-(4-Amino-3-nitrophenoxy)phthalonitrile (3) which is one of the precursor molecules of the phthalocyanine was obtained from 4-nitrophthalonitrile (1) and 4-amino-3-nitrophenol (2) with K₂CO₃ in DMF at 50 °C. The zinc(II) phthalocyanine (5) containing an unsymmetrical substituted 4-amino-3-nitrophenoxy group was synthesized by statistical condensation of two different phthalonitriles. 4-(4-Amino-3-nitrophenoxy)phthalonitrile (3) and 4,5-bis(hexylthio)phthalonitrile (4) were cyclotetramerized with zinc acetate in DMF at 170–180 °C to yield 2-(4-amino-3-nitrophenoxy)-9,10,16,17,23,24-hexa(hexylthio)phthalocyanine zinc(II) complex (5), which was then separated by column chromatography on silica gel. The unsymmetrically substituted compound was reduced to the diamine form (6) using hydrazine hydrate in the presence of Pd/C catalyst, and the product was purified with chromatographic separation. Compound 6 was then reacted with triisopropoxyborane in refluxing xylene to give 5H,12H,19H-tris[2-(3,4-diaminophenoxy)-9,10,16,17,23,24-hexa(hexylthio)phthalocyaninato zinc(II) diazaborolo] borazine (7). The resulting product was purified by column chromatography on silica gel. All the target unsymmetrical phthalocyanines and borazine derivative were characterized by elemental analysis, IR, UV–vis, and ¹H NMR. Boron and zinc(II) percents in 7 were quantified with ICP-MS. Impedance spectroscopy and dc measurements were performed on spin coated 5–7 films as a function of temperature (293–400 K). The dc results showed an activated conductivity dependence on temperature. The ac results gave a temperature dependent frequency exponent s. The results were compared with the prediction of the Quantum Mechanical Tunelling and Correlated Barrier Hopping models. The ac conductivity of the films was well represented by the form Aω^s. Gas sensing properties of the films for the volatile organic compounds (VOCs) (chloroform, acetone, carbontetrachloride and ammonia) were also investigated in the temperature range from 293 to 400 K. The operating temperature had a considerable effect on sensing characteristics. Maximum sensitivity to VOCs were observed at room temperature for all films. Cyclic voltammetry of compounds 6 and 7 in solution indicated that these compounds have similar voltammetric behaviour.     

Synthesis and spectroscopic properties of a series of octacationic water-soluble phthalocyanines

The synthesis, characterization of newly synthesized metal-free 2 and metallophthalocyanine complexes 3–5 (MPcs, M = Ni, Co, Cu) and quaternized metallophthalocyanine derivatives 3a, 5a (MPcs, M = Ni, Cu) containing 4,5-bis(quinolin-6-yloxy) substituents have been presented in this work. The new compounds have been characterized by using elemental analysis, UV–vis, IR, ¹H NMR, ¹³C NMR and MS spectroscopic data. Also, aggregation properties of Pcs were investigated at different concentrations in chloroform, dimethylformamide and water. The effect of the concentration on the aggregation properties of complexes 2–5 was studied in chloroform. No aggregation was demonstrated in chloroform from concentration between 1 × 10^?5 and 0.4 × 10^?5 M.     

3D fractal-based characterisation for engineered surface topography

We investigate the concept of surface roughness by assuming that z(x) verifies a Lipschitz condition in terms of variance var(z(x+Δ)−z(x))∝Δ^2H with 0<H<1 and Δ→0. Such surfaces are only locally self-affine at scale where the prev relation is verified. The Lipshitz Hölder exponent H, which is directly connected to the surface fractal dimension D, is determined from the log-log plot of σ²-(L) versus the characteristic size L of the sampling area. Different results are presented. The first, which concerns simulated profiles derived from the Weierstrass function, gives some indication on the accuracy of the method. The other concerns 3D analysis of real sandblasted surfaces parallel to a simulated fractal surface. An extension of the theoretical analysis to certain non isotropic surfaces is also presented and applied to a real ground surface.