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A series of disperse dyes, 9,10-anthraquinone containing dithiocarbamate, thiourea and triazole fragments, were prepared via consecutive refunctionalization of aminoanthraquinones in our previous studies and their structures were confirmed by the 1H, 13C NMR, IR spectra, LC-MS and elemental analysis data. The obtained compounds were applied on polyester fabrics by the exhaustion method at 130°C at pH 4.0-5.0, and their dyeing properties were evaluated by color measurements, the washing fastness test and the light fastness test. Many of these dyes gave solid and level dyeings on polyester fabric with low % concentration of dye. The dyed samples displayed very good color fastnesses. The color change and staining test results were quite good with ratings of “4-5” or above. The light fastness test results were also satisfactory for the most of the dyed samples.

In this study, firstly, five novel vitamin K3 analogues were synthesized by the reactions of vitamin K3 (2-methyl-1,4-naphthoquinone, also known as menadione) with some aromatic and heterocyclic ring substituted nucleophiles such as 2,4-dimethoxyaniline, 4-methoxyaniline, 4-benzylpiperidine and 1-(2-aminoethyl)piperazine in ethanol/Na2CO3, and 1-(diphenylmethyl)piperazine in chloroform/triethylamine (TEA) at room temperature. Their structures were elucidated by Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR), attached proton test nuclear magnetic resonance (APT-NMR) and mass spectrometry (MS). Secondly, in vitro cytotoxic effects of vitamin K3 analogues were investigated by MTT assay against three cancer cell lines (HeLa, U87 MG, and MCF-7) to evaluate their anticancer activity and a human embryonic kidney cell line (HEK-293) to check their cancer cell selectivity. One of the compounds, namely 2-((2,4-dimethoxyphenyl)amino)-3-methylnaphthalene-1,4-dione, was found to inhibit the growth of HeLa cervical cancer cells selectively, even better than vitamin K3, at a non-toxic concentration for healthy cells. The selectivity index of this compound for HeLa cells was calculated approximately as 3. Vitamin K3 was more effective against U87 MG and MCF-7 cells than its derivatives, moreover it was the only compound, which was significantly toxic to breast cancer cells, but its selectivity was poor. Furthermore, anticancer properties of piperazine derivatives of vitamin K3 were investigated by us for the first time in this study.

The ketene dithioacetal 3 generated from 2-nitroperchlorobutadiene 1 reacted with various heterocyclic amines and aliphatic, aromatic and heterocyclic thiols to produce functionalized new ketene-N,S,S-acetals and S,S,S-acetals 4a-f, 5a-h as heterocyclic dithiolanes. They were separated/purified by chromatographic methods and their exact structure characterization were made clear by spectroscopic methods. These compounds synthesized could act as effective drugs for versatile activity. Evaluation of the antimicrobial effect of the obtained substances determined derivatives 4e and 5h, which have MIC=15.6 μg/mL for the test culture of Mycobacterium luteum bacteria closing to the control drug Vancomycin. The obtained compounds can be proposed as a promising synthetic objects for future molecular design to enhance the antimicrobial action. Ketene dithioacetals 3, 4a, 4b, 4e, 5g (50 mg/kg) exhibited antiseizure effect comparable with reference drug (valproic acid) on the model of pentylenetetrazole-induced convulsions after single oral administration both at 3 h and 24 h. Furthermore, tested dithioacetals possessed prolonged antidepressant activity in forced swim test (FST) considerable decreasing the duration of immobility time compared to reference drug amitriptyline. This is the first study of the investigation of anticonvulsant and antidepressant activities of ketene dithioacetals.

The novel N-,O-substituted-5-Nitro-1,4-naphthoquinones (NQ) as regioisomers were synthesized by reactions of 2,3-dichloro-5-nitro-1,4-naphthoquinone with some heterocyclic rings which were substituted with various nucleophiles according to a Michael 1,4-addition mechanism. All synthesized compounds were characterized by elemental analysis, electrospray ionization mass spectrometry (ESI-MS), Fourier transform infrared spectroscopy (FT-IR), H-1-nuclear magnetic resonance (H-1 NMR) and attached proton test nuclear magnetic resonance (APTNMR). Two-dimensional techniques H-1-H-1 correlated spectroscopy (COSY) was used for characterization of compound 1a. Cyclic and square wave voltammetric and in situ UV-Vis spectroelectrochemical characterizations of NQ derivatives were carried out to determine redox mechanism of these molecules. Although in-situ FT-IR spectroelectrochemical studies of these type compounds were frequently reported in the literature, this is the first study for the in-situ UV-Vis spectroelectrochemical studies of NQ compounds in the literature. All NQs illustrated two NQ based and one nitro-based reduction reactions. While NQ based reduction couples were electrochemically and chemically reversible, observation of nitro reduction at more negative potentials made all processes irreversible. Altering the substituents of the NQ derivatives slightly influenced the redox potentials and chemical reversibility of the processes. Isomers of different NQ derivatives almost showed similar voltametric responses. Distinct spectral and color changes were observed during the redox reactions which indicated possible usages of these molecules in display technologies.

Researches with nitro compounds mainly relates to the synthesis of their derivatives used as unusual intermediate compounds. Because of their high reactivity in SNvin reactions, polyhalo-nitro-butadienes have been shown in many studies to have many properties as well as medical and pharmaceutical effects such as antitumor, bactericidal, fungicide and algicide. This study deals with the design, characterization of structures and the discovery of their antibacterial and antifungal properties based on new (E)-S- and (E)-N,S-polyhalonitrobutadiene analogues possessing piperazine, piperidine and morpholine groups. The antibacterial and antifungal activity of synthesized S- and N,S-substituted perhalo-nitro-butadienes were evaluated against to Escherichia coli B-906, Staphylococcus aureus 209-P, Mycobacterium luteum B-917 for bacteria and Candida tenuis VKM Y-70, Aspergillus niger F-1119 for fungi. Antimicrobial activity of the synthesized compounds was determined by using the diffusion method and serial dilution method. Compounds 2-Nitro-1,3,4,4-tetrachloro-1-hexylsulfanyl-1,3-butadiene and (E)-2,6-dimethyl-4-(3,4,4-trichloro-2-nitro-1-(octylthio)buta-1,3-dien-1-yl)morpholine with high antibacterial effect against strains E. coli and M. luteum and the derivative (E)-1-benzhydryl-4-(3,4,4-trichloro-1-(hexylthio)-2-nitrobuta-1,3-dien-1-yl)piperazine with antifungal agent against test-cultures A. niger and C. tenuis at MIC 1.9 µg/mL were identified as the most potent. Synopsis This study deals with the characterization of structures and the discovery of their antibacterial and antifungal properties based on new (E)-N,S-polyhalonitrobutadiene analogues. 1b and 7 with high antibacterial effect against strains E. coli and M. luteum. 9 with antifungal agent against test-cultures A. niger, C. tenuis at MIC 1.9 µg/mL were identified as the most potent.

The studies on nitronaphthoquinone derivatives are rare in the literature, and the nitro group associated with the aromatic ring in the quinone system is known to increase the biological activity of naphthoquinone due to its electron-withdrawing properties. In the course of quinone derivatives, the new N(H)-substituted-5-nitro-1,4-naphthoquinones (NQ) as regioisomers were synthesized by reactions of 2,3-dichloro-5-nitro-1,4-naphthoquinone with some heterocyclic ring substituted nucleophiles such as anilines, piperazines, or morpholines, according to a Michael 1,4-addition mechanism. Five NQ regioisomer couples having different functional group (2-chloro-isomers 3, 5, 7, 9 and 13; 3-chloro-isomers 2, 4, 6, 8 and 12) are reported here. All new synthesized compounds were characterized by spectroscopic methods and two-dimensional NMR techniques 1H-1H correlated spectroscopy (COSY).The synthesized NQ regioisomers were evaluated for catalase enzyme inhibitory activities and antioxidant efficiency. The synthesized regioisomers were screened for their antioxidant capacity using the cupric-reducing antioxidant capacity (CUPRAC) method. 2-Chloro-3-((2,4-dimethoxyphenyl)amino)-5-nitronaphthalene-1,4-dione (5) showed the highest antioxidant capacity with a 1.80±0.06 CUPRAC-trolox equivalent antioxidant capacity (TEAC) coefficient. Compound 5 also showed strongest catalase enzyme inhibitory activity. The antioxidant capacity results of all 2-chloro regioisomers are higher than the 3-chloro regioisomers. Likewise, also catalase enzyme inhibitory activities results were determined in the same way, except for one regioisomer pair. The catalase was effectively inhibited by the newly synthesized compounds, with % inhibition values in the range of 0.71-0.86%. Some of these NQ compounds also showed remarkable antioxidant capacities.

In this study, derivatives of new vitamin K3 were synthesized by the reactions of 2-methyl-1,4-naphthoquinone 1 with some heterocyclic ring substituted nucleophiles: 1-piperonylpiperazine 2, 1-(2-furoyl)piperazine 5, 1-(2-aminoethyl)piperidine 8, 1-(2-aminoethyl)pyrrolidine 10 and 2,6-dimethyl morpholine 12 in chloroform/triethylamine (TEA) or ethanol at room temperature. Their structures were characterized by Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR), attached proton test nuclear magnetic resonance (APT-NMR) and mass spectrometry (MS). Newly synthesized vitamin K3 derivatives (3, 4, 6, 7, 9, 11, 13, 14) have shown catalase inhibition activity and compound 13 has displayed remarkable potency against catalase enzyme. These compounds were also tested for their antioxidant capacity in vitro by CUPRAC method. New vitamin K3 (menadione) analogues.

The new anthraquinonylhydrazones were obtained by the interaction of 9,10-dioxoanthracene-1-diazonium sulfates with a number of α- and β-carbonyl-containing compounds under modified conditions of the Japp–Klingemann reaction, and a probable mechanism of the formation has been proposed. It was found that hydrazones, unsaturated in the second position of the anthraquinone ring, containing acetyl or ethoxycarbonyl moieties in the ylidene part of the molecule, are capable of eliminating these fragments. It has been experimentally established that hydrazones, free rotation around the N=C bond of which is possible, exist as one isomer due to the presence of an intramolecular hydrogen bond in the molecule. The anthraquinonylhydrazone of dimedone with action against the bacteria strains of Staphylococcus aureus 209-P, Mycobacterium luteum B-917, and fungus Candida tenuis VKM Y-70 was found. The hydrazones of dimedone and barbituric acid with a higher trolox equivalent antioxidant coefficients of antioxidant action were found using CUPRAC assay. In addition, the hydrazones of dimedone and barbituric acid exhibited better activity against catalase enzyme. Correlations between the structure of the synthesized hydrazones and their antioxidant activity have been defined.

The nitro group–substituted perhalogenobuta-1,3-diene (1) is important synthetic precursor in the synthesis of different heterocycles groups with high biological activity. Firstly, new N,S-substituted-perhalonitro-1,3-butadiene compounds were synthesized by the reactions of various amino or thiol containing nucleophiles with 1. The structures of all new compounds have been identified by using spectroscopic techniques (FT-IR, 1H-NMR, 13C-NMR, MS and microanalysis). Secondly, their antimicrobial properties were tested as potential antibacterial and antifungal agents. Antimicrobial activity of synthesized N,S-substituted perhalonitrobutadienes 4a–j and 5a–d was evaluated against Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 bacteria and Candida tenuis VKM Y-70 and Aspergillus niger F-1119 fungi and the compounds 4c, 4d, 5a and 5b with high antifungal action against test-culture Aspergillus niger at MIC values 0.9–1.9 μg/cm3 were identified as the most potent.

A variety of new derivatives of 9,10-anthracenedione with mono- and bisdithiocarbamate moiety in the non-catalytic conditions have been synthesized. The obtained compounds were screened for their antioxidant capacity using the cupric-reducing antioxidant capacity (CUPRAC) method. Three of the compounds showed CUPRAC-Trolox equivalent antioxidant capacity (TEAC) coefficients higher than trolox. Scavenging effects on reactive oxygen species (ROS), hydroxyl radical scavenging (HRS), hydrogen peroxide scavenging (HPS), and superoxide anion radical scavenging (SARS) of all synthesized compounds were determined. It was established that the results of HRS-, HPS-, and SARS-CUPRAC methods for three compounds are in accordance with TEAC-CUPRAC assay data.

The aim of this study was synthesis of substituted naphthoquinone derivatives and testing of their dyeability on polyester fibers. There are few studies concerned with dyeing properties of heteroatom-substituted-1,4-naphthoquinone compounds in the literature. A series of N-, S-, O-substituted-1,4-naphthoquinone compounds were synthesized via vinylic substitution. Their structures were determined by infrared spectrometry, 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. The ultraviolet-visible absorption spectra of the dyes were examined in different solvents. The dyes were applied to polyester fibers and dyeing properties were investigated. The rubbing fastness, wash fastness and optical properties of the synthesized compounds also were measured.

A novel series of 1,4-naphthoquinones substituted containing sulfur, nitrogen, oxygen atoms were synthesized. The structures of the novel products were characterized by using the various spectroscopic techniques such as 1H nuclear magnetic resonance (NMR), 13C NMR, mass spectrometry (MS), Fourier transform infrared spectroscopy (FT-IR) and microanalysis. The crystal structures of 2,3-bis(benzylsulfanyl)-1,4-napthoquinone 4 and 2,3-bis(ethylsulfanyl)-1,4-naphthoquinone 7 were determined by using X-ray single crystal diffraction method. Electrochemical behaviors of some 1,4-naphthoquinone (NQ) derivatives 3, 4, 7, 8, 9, 10, 12, 13, 15, 16, 17, 19 and 20 were studied by using cyclic voltammetry, square wave voltammetry and in-situ UV-Vis spectroelectrochemistry. The substituents of the NQ derivatives significantly altered the redox mechanism. In-situ UV-Vis spectroelectrochemical analyses of NQs supported the proposed redox mechanism.

Mertoglu, Elif/0000-0002-3606-4722; ARDA, NAZLI/0000-0002-1043-5652; Aydinli, Serdar Goksin/0000-0002-2681-6011; UCAR, Evren ONAY/0000-0003-1152-4881; Sayil, Makbule Cigdem/0000-0001-9611-3533; Kacmaz, Aysecik/0000-0001-8420-6855 WOS:000471119600003 In the course of biological properties of quinone derivatives, the N(H)-, S- and S,S-substituted-1,4-naphthoquinones were synthesized by reactions of 2,3-dichloro-1,4-naphthoquinone with different amines (2-morpholinoaniline, tert-butyl 4-aminobenzoate, 4-tert- butyl-benzylamine, N-(3-aminopropyl)-2-pipecoline, 2-amino-5,6-dimethylbenzothiazole, N,N'-diphenyl- p-phenylenediamine) and thiolat (sodium 2-methyl-2-propanethiolate). All new products were characterized by MS-ESL UV-Vis, FT-IR, H-1 NMR, C-13 NMR. The antiproliferative activities of these compounds on human cervical cancer (HeLa) cells were evaluated by MTT (3[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. Although all derivatives inhibited cell growth, the most active compound was 2-(tert-butylthio)-3-chloronaphthalene-1,4-dione 5 (IC50 =10.16 mu M) against the HeLa cells. Scientific Research Projects Coordination Unit of Istanbul University-Cerrahpasa [36017, YADOP-32026] The authors would like to express their gratitude to Scientific Research Projects Coordination Unit of Istanbul University-Cerrahpasa for financial support (Project Numbers: 36017, YADOP-32026).

The reaction of 1,3-bis(1H-benzimidazol-2-yl)-2-oxapropane (L) with Co(ClO4)2?6H2O in absolute ethanol produces di[1,3-bis(1H-benzimidazol-2-yl)-2-oxapropane-k2N,N?]cobalt(II)diperchlorate chelate complex ([Co(L)2](ClO4)2, 1). The complex 1 was characterized by elemental analysis, magnetic moment, molar conductivity, thermogravimetric analysis, FT-IR, UV-visible, mass spectrometry, and its solid state structure was determined by single crystal X-ray diffraction. According to the thermogravimetric analysis data, there is no any water coordinated or uncoordinated in 1 as well as elemental analysis. The complex 1 has 1:2 M:L ionic characteristic according to the molar conductivity. In the complex, the distances between the cobalt and the ethereal oxygen atoms (Co1-O2: 2.805(3); Co2-O1: 2.752(2) ?) show the semi-coordination bonding and the Co(II) ion is six-coordinated with a N4O2 ligand set, resulting in a distorted octahedron.

2,3-Dichloro-1,4-naphtoquinone 1 compound was reacted with octadecanethiol 2 in two different mole ratio. Compound 3 was obtained from the reaction of 1 and 2 in 1:2 mole/mole ratio. Compounds 7 and 8 were obtained from reaction of 1 and 2 in 1:1 mole/mole ratio and known compound 9 was synthesized as by-product in this reaction. Novel compounds 5a-e were obtained from reaction of 1 and related thiols 4a-e. Known compounds 6c and 6e were synthesized as by-product in this reaction. The structures of the compounds were characterized by elemental analysis, UV-vis, FTIR, 1 H-NMR, 13 C-NMR and Mass spectroscopies.

4-Methyl-1-(3,4,4-trichloro-1-cyclohexylsulfanyl-2-nitro-buta-1,3-dienyl) piperidine (2a) and 4-(3,4,4-trichloro-1-decylsulfanyl-2-nitro-buta-1,3-dienyl) morpholine (3b) were synthesized, and their crystal structures were determined. The compound 2a is monoclinic, with space group P21/n, a = 13.2874(8), b = 9.7584(4), c = 15.9479(9) A, β = 109.110(3)°. V = 1953.91(18) A3, Z = 4. The cyclohexyl and piperidine rings adopt chair conformation. The compound 3b is monoclinic, with space group P 1 21/c 1, a = 15.7741(3), b = 8.9335(10), c = 16.7775(4) A, β = 100.7382(13)°. V = 2322.85(8)A3, Z = 4. The morpholine ring is in a chair conformation. The butadiene unit assumed a configuration close to cissoid in both structures, and their spectroscopic properties were investigated.

The tetrakis(thio)-substituted-1,4-benzoquinone products 4a-e, 6, 7, and the mono(alkoxy)-tris(thio)-substituted-1,4-benzoquinone products 5a-e and 8a-e were synthesized from the reactions of p-chloranil with some thiols and mixture of two different thiol compounds in alcohol in the presence of Na 2 CO 3 at room temperature. The structures of the novel S,S,S,S- and S,S,S,O- substituted products, which were obtained by the reactions of p-chloranil as a starting compound with n-propanethiol, n-pentanethiol, n-decanethiol, n-dodecanethiol, 2-methyl-2-propanethiol, and mixture of n-decanethiol and n-cyclohexanethiol as S-nucleophiles, were characterized by spectroscopic methods.

Thiosubstituted nitrodiene compound 1a was obtained from 2-nitropentachlorobutadiene and dodecanethiol. Compound 1b was prepared from 2-nitropentachlorobutadiene and hexadecanethiol. Monosubstituted diene compounds 1a and 1b reacted with piperazines such as derivatives of 2 and 4 in CH2Cl2 and gave the novel compounds. 2-Nitro-3,4,4-trichloro-1-dodecylthio-1-(2-fluorophenylpiperazinyl]- 1,3-butadiene (3d) was synthesized and its crystal structure was determined.

Tetrakis‐(4‐chlorophenylthio)‐butatriene (3a) and tetrakis‐(tert‐butylthio)‐butatriene (3b) were synthesized, and their crystal structures were determined. The compound 3a is monoclinic, space group P21/c, a=6.9785(8), b=8.6803(9), c=22.884(2) A, β=93.887(6)o, V=1383.0(3) A3, Z=2. The compound 3b is monoclinic, space group P21/n, a=11.0615(6), b=10.8507(4), c=11.2717(6) A, β =116.427(2)o, V=1211.5(1) A3, Z=4. The title compounds 3a and 3b reside on an inversion center so that only half of the molecule is crystallographically unique. Both compounds are not planar. The crystal structures of 3a and 3b have cumulated double bonds. The C7–C8–C8i and C5–C6–C6i angles that show the linearity in both structures, respectively, are 176.4(3)° in 3a and 175.6(2)° in 3b.

Summary Effects of the gel preparation temperature Tprep and the initial monomer concentration c on the swelling and the porosity properties of poly(N-isopropylacrylamide) (PNIPA) networks are described. PNIPA networks were prepared by free-radical crosslinking copolymerization of N-isopropylacrylamide and N,N’-methylene(bis)acrylamide (BAAm) in aqueous solutions. The crosslinker (BAAm) concentration in the initial monomer mixture was kept constant at 30 wt %. It was shown that macroporous PNIPA networks with a stable porous structure can be prepared at Tprep = 22.5 0 C and at an initial monomer concentration c > 5 w/v %. The PNIPA networks contain pores of about 0.1 μm in radius, corresponding to the interstices between the microspheres. The experimental data also show collapse of the porous structure in PNIPA networks formed at higher temperatures.

The swelling and shrinking behaviors of a series of poly(N-isopropylacrylamide) (PNIPA) hydrogels are studied in aqueous solutions of sodium dodecylbenzenesulfonate (SDBS). Between 0 and 3 mol % 2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS) is used as an ionic comonomer in the hydrogel synthesis. It is shown that the collapsed PNIPA gels in water at 52°C start to swell above a critical SDBS concentration in the external solution. This critical concentration decreases as the ionic group content of PNIPA gel increases. A comparison of the swelling and shrinking experiments in SDBS solutions indicates strong hysteresis behavior of PNIPA gels. A more diluted solution is required to make a swollen gel start to reshrink than to cause gel swelling. The results show strong attractive forces between the isopropyl groups of the PNIPA network and the DB groups of SDBS molecules. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1228–1232, 2002

The formation conditions of macroporous poly( N -isopropyl)acrylamide (PNIPA) networks by free-radical crosslinking copolymerization are described. The networks were prepared in water at an initial monomer concentration of 20% using N , N ′-methylene(bis)acrylamide (BAAm) as the crosslinker. The synthesis parameters varied were the crosslinker concentration and the gel preparation temperature T prep . Depending on these parameters, the variations of the swelling, mechanical and texture properties of the networks were investigated. It was shown that, after passing a critical crosslinker concentration (2–5% BAAm), the network structure changes from homogeneous to heterogeneous ones. Further increase of the crosslinker content increases both the rate of swelling and the porosity of the networks. Heterogeneous PNIPA networks consist of spherical globules called microspheres of 0.1–0.5 μm in diameter aggregated to large, unshaped, discrete clusters with dimensions of a few μm. At 30% BAAm, the structure looks like cauliflowers, typical for a macroporous network. The dependence of the elastic moduli of PNIPA gels on the crosslinker content shows three different regimes depending on the structure of the networks. Increasing T prep from 9 to 50°C at a fixed BAAm content increases both the rate of swelling and the swelling capacity of the networks, while the total porosity decreases.

The role of the preparation temperature of poly(N-isopropylacrylamide) (PNIPA) gels on their swelling behavior in water and in aqueous solutions of sodium dodecylbenzenesulfonate was investigated. PNIPA gels were prepared by free-radical crosslinking copolymerization of N-isopropylacrylamide and N,N'-methylene(bis) acrylamide in water at fixed monomer and crosslinker concentrations. The equilibrium swelling ratio of the gels increases first slightly up to about 20 degrees C then rapidly with increasing gel preparation temperature. Magnitude of the collapse transition in water at 34 degrees C becomes larger as the gel preparation temperature increases. Calculations indicate a decrease in the effective crosslink density of PNIPA gels with increasing preparation temperature. The gels prepared at temperatures higher then 20 degrees C were heterogeneous consisting of highly crosslinked regions interconnected by the PNIPA chains.

Singlet energies and fluorescence quantum yields of synthesized dihydrocarbazolocarbazole, 1 , dimethylcarbazolocarbazole, 2 , dibenzylcarbazolocarbazole, 3 , were measured to be between 76.5−74.3kcal/mol and 0.07−0.02, respectively. A Stern-Volmer plot of fluorescence quenching of dihydrocarbazolocarbazole, 1 , with 2,4,5,7-tetranitrofluorenone, 4 , has given a rate constant of quenching of k q =7.4×10 12 M −1 s −1 . The free energies of the exothermic electron transfer reaction are calculated to be −33.6 kcal/mol for dihydrocarbazolocarbazole, 1 , and −26.8 kcal/mol for dimethylcarbazolocarbazole, 2 . High values for the rate of fluorescence quenching and the free energies are the evidence for an electron transfer process between these strong π-electron donor-acceptor complexed molecules.

Virgatic acid triterpene, extracted from salvia plants, is found to be quenched by singlet oxygen at chemical and photosensitized oxygenations. A charge-transfer energy transfer is attributed to the quenching of singlet oxygen, which may be accounted as a protective mechanism of salvia plants to photooxygenations.

Ketene dithioacetals 3a-f, dithia compounds 4c, 4f and a disulphide compound 5c were prepared from 2-nitroperhalo-1,3-butadiene (1) and dithiols (2). Benzthiazoles (6a) and (6b) were prepared from the reaction of 1 with 2-aminothiophenol in diethylether.

The tetrakis(thio)-substituted-1,4-benzoquinone products 4a-e, 6, 7, and the mono(alkoxy)-tris(thio)-substituted-1,4-benzoquinone products 5a-e and 8a-e were synthesized from the reactions of p-chloranil with some thiols and mixture of two different thiol compounds in alcohol in the presence of Na 2 CO 3 at room temperature. The structures of the novel S,S,S,S- and S,S,S,O- substituted products, which were obtained by the reactions of p-chloranil as a starting compound with n-propanethiol, n-pentanethiol, n-decanethiol, n-dodecanethiol, 2-methyl-2-propanethiol, and mixture of n-decanethiol and n-cyclohexanethiol as S-nucleophiles, were characterized by spectroscopic methods.

In the title compound, C30H45Cl3FN3O2S, the piperazine ring is in a chair conformation. The alkyl substituent has a fully extended conformation.

The mol­ecule of the title compound, C10H4Cl5NO2S, is not planar. The chloro­phenyl ring and the butadiene group are inclined at an angle of 59.5 (1)°.