Microwave-assisted synthesis and characterization of novel metal-free and metallophthalocyanines containing four 14-membered tetraaza macrocycles

The novel tetrasubstituted metal-free phthalocyanine (6) and metallophthalocyanines (7, 8) bearing four 14-membered tetraaza macrocycles moieties on peripheral positions have been synthesized by cyclotetramerization reaction of phthalonitrile derivative (5) in a multi-step reaction sequence. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV-vis, elemental analysis and MS spectral data.     

New long-chain-substituted polymeric metal-free and metallophthalocyanines by microwave irradiation: Synthesis and characterization

A tetranitrile monomer N,N-bis{2-[2-(3,4-dicyanophenoxy)ethoxy]ethyl}-4-methylbenzenesulfonamide (3) was synthesized by nucleophilic aromatic substitution of N,N-bis[2-(2-hydroxyethoxy)ethyl]-4-methylbenzenesulfonamide (1) onto 4-nitrophthalonitrile (2). The metal-free phthalocyanine polymer (4) was prepared by the reaction of a tetranitrile monomer 3 in 2-(dimethylamino)ethanol. Ni(II), Co(II) and Cu(II) phthalocyanine polymers were prepared by the reaction of the tetranitrile compound with the chlorides of Ni(II), Co(II) and Cu(II) in 2-(dimethylamino)ethanol (DMAE). The Zn(II)-phthalocyanine polymer was prepared by the reaction of the tetranitrile compound with the acetate of Zn(II) in DMAE. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV–Vis, elemental analysis and MS spectral data.     

Synthesis,characterization and electrochemistry of a new organosoluble metal-free and metallophthalocyanines

4-[2-(Phenylthio)ethoxy]phthalonitrile 3 was synthesized by nucleophilic displacement of nitro group in 4-nitrophthalonitrile with 2-(phenylthio)ethanol 1. The metal-free phthalocyanine 4 was prepared by the reaction of a dinitrile monomer with 2-(dimethylamino)ethanol. Ni(II), Co(II), Cu(I) phthalocyanines 5, 7, 8 were prepared by reaction of the dinitrile compound with the chlorides of Ni(II), Co(II), Cu(I) in DMAE. Zn(II) phthalocyanine 6, was prepared by reaction of the dinitrile compound with the acetates of Zn(II) in DMAE. Electrochemical behaviours of novel metal-free, Co(II) and Zn(II) phthalocyanines were investigated by cyclic voltammetry, potential differential pulse voltammetry techniques. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV–Vis, elemental analysis and MS spectral data.     

Synthesis and characterization of metal-free and metallophthalocyanines containing N2S2-type macrocyclic moieties linked ferrocenyl groups

The new metal-free (4) and metallophthalocyanines (5) carrying macrocyclic moieties linked ferrocenyl groups have been synthesized by direct cyclotetramerization of the pre-cursor, 12,13-dicyano-4,7-bis(ferrocenylmethyl)-2,3,4,5,6,7,8,9-octahydrocyclobenzo[k]-4,7-diaza-1,10-dithiacyclododecine (3) which has been prepared by the macrocyclization reaction of 1,2-bis(2-iodoethylmercapto)-4,5-dicyanobenzene (1) with N,N′-ethylenebis-(ferroceneylmethyl)amine (2), in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a strong organic base. Nickel (II) phthalocyanine (5) was synthesized by the reaction of metal-free phthalocyanine with anhydrous NiCl₂ in dry quinoline. The target compound and its intermediates have been characterized by a combination of elemental analysis and ¹H, ¹³C NMR, IR, UV-Vis and MS spectral data.     

Microwave-assisted synthesis and characterization of phthalocyanines substituted with azo compound containing eugenol moiety

The new metallophthalocyanines (Co, Ni, Cu, and Zn) substituted with azo compound containing eugenol moiety are described. Firstly, azo compound (I) containing eugenol moiety was synthesized by treating eugenol with p-hydroxyaniline. Then phthalonitrile compound (1) was synthesized by microwave-assisted synthesis method. The purification of phthalonitrile compound (1) was carried out by column chromatographic separation. Intramolecular hydrogen bonding in the azo compound (I) prevent base-catalyzed nucleophilic aromatic substitution of OH group belongs eugenol. At the last step, metallophthalocyanines (1a, 1b, 1c, and 1d) were synthesized by the microwave irradiation. The microwave-assisted synthesis method reduces reaction times and enhances the yield of the reactions. All phthalocyanine compounds are soluble in DMF and DMSO. The structures were confirmed by elemental analysis, ¹H NMR, ¹³C NMR, UV/Vis, IR and Mass spectra.     

Synthesis,characterization and electrochemical properties of novel metal free and zinc(II) phthalocyanines of ball and clamshell types

The phthalodinitrile derivative 1 was prepared by the reaction of 4-nitrophthalonitrile and 1,3-dimethoxy-4-tert-butylcalix[4]arene in dry dimethylsulfoxide as the solvent, in the presence of the base K₂CO₃, by nucleophilic substitution of an activated nitro group in an aromatic ring. The tetramerization of compound 1 gave a binuclear zinc(II) phthalocyanine and a metal-free phthalocyanine of the ball type, 2 and 3, respectively. Its condensation with 4,5-bis(hexylthio)phthalonitrile results in a binuclear phthalocyanine of the clamshell type, 4. The newly synthesized compounds were characterized by elemental analysis, UV–Vis, IR, MS and ¹H NMR spectra. The electronic spectra exhibit an intense π → π^∗ transition with characteristic Q and B bands of the phthalocyanine core. The electrochemical properties of 2–4 were examined by cyclic voltammetry in non-aqueous media. The voltammetric results showed that while there is no considerable interaction between the two phthalocyanine rings in 4, the splitting of a molecular orbital occurs as a result of the strong interaction between the phthalocyanine rings in 2 and 3.     

New olefinic centred binuclear clamshell type phthalocyanines: Design, synthesis, structural characterisation, the stability and the change in the electron cloud at olefine-based symmetrical diphthalonitrile fragment by the combined application of UV–Vis electronic structure and theoretical methods

The olefinic centred Schiff base (3) was obtained from the condensation of substituted dialdehyde (1) with 2-amino-4-methylphenol (2) in a 1:2 ratio. The diphthalonitrile derivative (5) was prepared by the reaction of 4-nitrophthalonitrile (4) and compound (3) in dry dimethylformamide/potassium carbonate. The key product (5) was obtained by nucleophilic substitution of an activated nitro group into an aromatic ring. The cyclotetramerization of compound (5) with phthalonitrile (6) in 1:6.15 ratio gave the expected metal-free phthalocyanine of clamshell type (7), and with metal salts of Zn(II), Ni(II), Co(II) and Cu(II) gave metallophthalocyanines of clamshell types (8-11), respectively in dimethylaminoethanol/1,8-diazabycyclo[5.4.0]undec-7-ene system. The products were purified by several techniques such as crystallization and preparative thin layer chromatography. The newly prepared compounds were characterised by a combination of elemental analyses, IR, ¹H/¹³C NMR, MS and UV-Vis spectroscopy.     

Derivatizable novel β-tetra 7-oxycoumarin-3-carboxylate substituted metallophthalocyanines: Synthesis and characterization

In this study, a novel phthalonitrile, ethyl 7-(3,4-dicyanophenoxy)coumarin-3-carboxylate (1), was prepared and characterized. The metallophthalocyanines (3–6) were prepared by cyclotetramerization of 1 with the corresponding metal salts {Zn(OAc)₂·2H₂O, Co(OAc)₂·4H₂O, Cu(OAc)₂, Ni(OAc)₂·4H₂O} in 2-chloronaphthalene. Reaction of 3 with aqueous hydrochloric acid gave the coumarino-zincphthalocyanine (3a) carrying carboxyl groups at the 3-position of all the coumarin moieties. Treatment of compound 3a with aqueous NaOH_./AgNO₃ or aqueous NaOH in N,N-dimethylformamide (DMF) gave the expected silver (3c) or sodium (3d) salts, respectively. The four carboxylic groups in coumarino-zincphthalocyanine (3a) and the four carboxylate groups in 3d make the compounds have good solubility in water. Heating of the acyl chloride derivative of 3 with morpholine in DMF yielded the corresponding 3-carboxymorpholinamide (3b). The newly prepared compounds, phthalonitrile and metallophthalocyanines, have been characterized by FT-IR, UV–Vis, MALDI-TOF and ¹H NMR spectroscopies.     

Synthesis of an octasubstituted galactose zinc(II) phthalocyanine

4,5-Bis(1,2:3,4-di-O-isopropylidene-α-d-galactopyranos-6-yl)phthalonitrile (3) was prepared by S_NAr reaction of diacetone galactose 1 and 4,5-difluorophthalonitrile (2) in 96% yield. Cyclotetramerization of 3 was achieved via its isoindoline derivative 4, affording the peripherally octasubstituted galactose zinc(II) phthalocyanine 5 in 29% yield. Deprotection of 5 gave the highly water soluble octasubstituted galactose zinc(II) phthalocyanine 6 in 81% yield which will be applied as a photosensitizer in photodynamic therapy.     

The synthesis, using microwave irradiation and characterization of novel, metal-free and metallophthalocyanines

The synthesis of novel metal-free (4) and metallophthalocyanines (5, 6, 7 and 8) were prepared by cyclotetramerization of a novel 4-[2-(1-naphthyloxy)ethoxy]phthalonitrile (3). New substitute phthalocyanines showed the enhanced solubility in organic solvents. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV-Vis and MS spectral data.     

Synthesis, characterization and aggregation behaviour of novel peripherally tetra-substituted octacationic water soluble metal-free and metallophthalocyanines

In this study, a new phthalonitrile derivative 3 bearing 1,3-bis[3(dimethylamino)phenoxy]propan-2-ol 1, metal-free phthalocyanine (Pc) 4, metallophthalocyanines (MPcs) 5–7 and their quaternized derivatives 4a–7a were synthesized. Metal-free Pc 4 was prepared by cyclotetramerization of phthalonitrile derivate 3 and MPcs 5–7 were synthesized by heating 3 with NiCl₂, CoCl₂ and CuCl₂ in n-pentanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, respectively. Quaternization of the dimethylamino functionality produced quaternized octacationic water soluble metal-free, Ni, Co and Cu Pcs which were soluble in water, DMF, DMSO. The aggregation behaviour of these compounds were investigated in different concentrations of chloroform for metal-free, Ni, Co and Cu Pcs. The effect of solvents on absorption spectra were studied in various organic solvents. The novel compounds were characterized using IR, ¹H-, ¹³C NMR, UV–vis and MS spectral data.     

A novel metal-free and metallophthalocyanines containing four 19-membered dithiadiazadioxa macrocycles by microwave irradiation: Synthesis and characterization

The novel tetrasubstituted metal-free phthalocyanine (5) and metallophtalocyanines (6, 7 and 8) bearing four 19-membered dithiadiazadioxa macrocyclic moieties on peripheral positions have been synthesized by cyclotetramerization reaction of phthalonitrile derivative (4) in a multi-step reaction sequence. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV-Vis, elemental analysis and MS spectral data.     

Synthesis,characterization, and electrochemical,electrical and gas sensing properties of a novel tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine

A novel tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu₂Pc₄) (5) has been synthesized by the reaction of dimeric lutetium(III) phthalocyanine (4) with two equiv. of dilithium octakis hexylthiophthalocyanine in amyl alcohol. The phthalonitrile derivative 1 was obtained through the displacement reaction of 4-nitrophthalonitrile with 1,3-dimethoxy-4-tert-butylcalix[4]arene and was converted to the isoindoline derivative 2 by bubbling ammonia gas in dry MeOH. Compound 4 was prepared from 2, 4,5-bis(hexylthio)-1,2-diiminoisoindoline (3), and lutetium acetate in dry DMF. The new compounds and phthalocyanines were characterized by elemental analysis, IR, UV–Vis, ¹H NMR, ESR and MALDI-TOF MS spectra. The electrochemical properties of 4 and 5 have been examined by cyclic voltammetry, and compared. Distinctive differences between the voltammetric behaviour of 4 and 5 were detected. These differences were compatible with the structures of the compounds. A detailed study of the effect of temperature on the d.c. conductivity and impedance spectra (40–10⁵ Hz) of spin coated films of 4 and 5 at temperatures between 290 K and 420 K was carried out. By analyzing the d.c. electrical behaviour of the 5 film, it was found that the experimental data are described by a thermally activated conductivity dependence on temperature with an activation energy of 0.77 eV. The a.c. results give a power law behaviour, σ_a.c. = A(T)ω^s, in which the frequency exponent s decreases with temperature. The sensing behaviour of the film for the online detection of volatile organic solvent vapors was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the target molecules on the coating surface cause a reversible negative frequency shift of the resonator. Thus, a variety of solvent vapors can be detected by using the 5 film as sensitive coating, with sensitivity in the ppm and response times in the order of several seconds depending on the dipole moment of the organic solvent.     

Synthesis and characterization of a new organo-soluble metal-free and metallophthalocyanines bearing flexible moieties

This paper describes a new symmetric metal-free phthalocyanine and its transition metal complexes which were prepared by a condensation of 1,2-dihydroacenaphthylen-1-ol 1 and 4-nitro phthalonitrile 2 with Co(II), Ni(II), Cu(II), and Zn(II) salts in 2-(dimethylamino)ethanol, respectively. The novel phthalocyanines bearing oxygen donor atoms on peripheral position have been characterized by IR, UV-Vis, ¹H NMR, ¹³C NMR, Mass spectra and elemental analysis. The thermal behaviours of 4-8 were investigated by TG/DTA.     

An efficient microwave assisted synthesis of novel class of Rhodanine derivatives as potential HIV-1 and JSP-1 inhibitors

(Z)-5-(2-(1H-Indol-3-yl)-2-oxoethylidene)-3-phenyl-2-thioxothiazolidin-4-one (7a-q) derivatives have been synthesized by the condensation reaction of 3-phenyl-2-thioxothiazolidin-4-ones (3a-h) with suitably substituted 2-(1H-indol-3-yl)-2-oxoacetaldehyde (6a-d) under microwave condition. The thioxothiazolidine-4-ones were prepared from the corresponding aromatic amines (1a-e) and di-(carboxymethyl)-trithiocarbonyl (2). The aldehydes (6a-h) were synthesized from the corresponding acid chlorides (5a-d) using HSnBu₃.     

Synthesis and photophysical properties of metal free, titanium, magnesium and zinc phthalocyanines substituted with a single carboxyl and hexylthio groups

2,3,9,10,16,17,23,24-Octakis(hexylthio)phthalocyanines (4a-6a) and 2-carboxy-9,10,16,17,23,24-hexakis(hexylthio)phthalocyanines (4b-6b) were synthesized using a one-pot method by cyclotetramerization of the phthalonitriles: 4,5-bis(hexylthio)phthalonitrile and carboxylic acid phthalonitrile. 2-Carboxycatecholato-2,3,9,10,16,17,23,24-octakis(hexylthio)phthalocyaninatotitanium(IV) (8) was prepared from 2,3,9,10,16,17,23,24-octakis(hexylthio)phthalocyaninatooxotitanium(IV) (7). The structures of these compounds were characterized by using elemental analyses, UV-Vis, FT-IR, ¹H NMR and mass spectroscopies. Their photophysical properties were also studied. The Φ_F values are 0.12, 0.02, 0.10, 0.06, 0.10, 0.06, 0.65, 0.80 and the Φ_T values are 0.58, 0.56, 0.57, 0.64, 0.22, 0.48, 0.17, 0.12 for 4-8, respectively. The Φ_F value for complex 8 is higher than ever reported for phthalocyanine complexes. The triplet lifetimes (τ_T) values for all the complexes were generally good, ranging from 50 to 310 μs, and generally increased in the presence of the single carboxyl group. These complexes showed reasonable triplet quantum yields and lifetimes, and hence have potential for use as photosensitizers in photodynamic therapy (PDT) of cancer.     

Synthetic access to optically active isoflavans by using allylic substitution

A general approach to the (S)- and (R)-isoflavans was invented, and efficiency of the method was demonstrated by the synthesis of (S)-equol ((S)-3), (R)-sativan ((R)-4), and (R)-vestitol ((R)-5). The key step is the allylic substitution of (S)-6a (Ar¹=2,4-(MeO)₂C₆H₃) and (R)-6b (Ar¹=2,4-(BnO)₂C₆H₃) with copper reagents derived from CuBr·Me₂S and Ar²-MgBr (7a, Ar²=4-MeOC₆H₄; 7b, 2,4-(MeO)₂C₆H₃; 7c, 2-MOMO-4-MeOC₆H₃), furnishing anti S_N2′ products (R)-8a and (S)-8b,c with 93-97% chirality transfer in 60-75% yields. The olefinic part of the products was oxidatively cleaved and the Me and Bn groups on the Ar¹ moieties was then removed. Finally, phenol bromide 9a and phenol alcohols 9b,c underwent cyclization with K₂CO₃ and the Mitsunobu reagent to afford (S)-3 and (R)-4 and -5, respectively.     

Synthesis and characterization of new metal-free and metallophthalocyanines fused α-methylferrocenylmethoxy units

Synthesis of metal-free and metallophthalocyanines bearing α-methylferrocenylmethoxy units was described. Precursor 3 required for the preparation of phthalocyanines 4–9, was synthsized by the nucleophilic aromatic substitution reaction between α-methylferrocenylmethanol and 4-nitrophthalonitrile in dry DMF. The metal-free phthalocyanine 4 was prepared from 4-(α-methylferrocenylmethoxy)phthalonitrile 3 in 1-pentanol with a catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Metallophthalocyanines (M = Zn, Cu, Co, Ni and Pb) were prepared by cyclotetramerization reaction of phthalonitrile with appropriate materials. The phthalonitrile, metal-free and metallophthalocyanines were characterized by ¹H and ¹³C NMR, FT-IR UV–Vis and mass spectral data, as well as elemental analyses, which were consistent with the proposed structures.     

Microwave-assisted synthesis of novel bis(2-thioxothiazolidin-4-one) derivatives as potential GSK-3 inhibitors

(5Z,5′Z)-3,3′-(1,4-Phenylenebis(methylene)-bis-(5-arylidene-2-thioxothiazolidin-4-one) derivatives (5a-r) have been synthesized by the condensation reaction of 3,3′-(1,4- or 1,3-phenylenebis(methylene))bis(2-thioxothiazolidin-4-ones) (3a,b) with suitably substituted aldehydes (4a-f) or 2-(1H-indol-3-yl)2-oxoacetaldehydes (8a-c) under microwave conditions. The bis(2-thioxothiazolidin-4-ones) were prepared from the corresponding primary alkyl amines (1a,b) and di-(carboxymethyl)-trithiocarbonyl (2). The 2-(1H-indol-3-yl)-2-oxoacetaldehydes (8a-c) were synthesized from the corresponding acid chlorides (7a-c) using HSnBu₃.     

A new polymeric phthalocyanine containing 16-membered tetrathia macrocyclic moieties by microwave irradiation: Synthesis and characterization

Tetranitrile monomer (3) was synthesized by nucleophilic aromatic substitution of 1,5,9,13-tetrathiacyclohexadecane-3,11-diol (1) onto 4-nitrophthalonitrile (2). The metal-free phthalocyanine polymer (4) was prepared by the reaction of a tetranitrile monomer with 4-({11-[3-cyano-4-(cyanomethyl)phenoxy]-1,5,9,13-tetrathiacyclohexadecan-3-yl}oxy)phthalonitrile in 2-(dimethylamino)ethanol. Ni(II), Co(II), Cu(I)-phthalocyanine polymers were prepared by the reaction of the tetranitrile compound with the chlorides of Ni(II), Co(II) and Cu(I) in DMAE. Zn(II)-phthalocyanine polymer was prepared by the reaction of the tetranitrile compound with the acetates of Zn(II) in DMAE. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV-Vis, elemental analysis and MS spectral data.