Electrocarboxylation of chloroacetonitrile by a Cobalt(I) complex of terpyridine

The electrocarboxylation of chloroacetonitrile (NC–CH₂–ClRCl) mediated by [Co^IIL₂]²⁺ (L = terpyridine) was investigated by cyclic voltammetry. Electrochemical studies under argon atmosphere showed that the monoelectronic reduction of [Co^IIL₂]²⁺ yielded a Cobalt(I) complex which after the loss of a terpyridine ligand reacted with chloroacetonitrile. The oxidative addition of chloroacetonitrile on [Co^IL]⁺ gave an alkylCobalt(III) complex [R–Co^IIIL]²⁺ which was reduced into an alkylCobalt(II) complex, highly unstable and decomposed into an alkyl anion and a Cobalt(II) complex. Under carbon dioxide atmosphere, Cobalt(I) complex was shown to be unreactive towards CO₂ but CO₂ insertion was observed in the alkylCobalt(III) complex [R–Co^IIIL] ²⁺ giving probably a CO₂ adduct [R–Co^IIIL(CO₂)]²⁺. This adduct presented a strong adsorption at the carbon electrode and was reduced at potential less cathodic than the one of alkylCobalt(III) complex. After reduction, the carboxylate RCO₂⁻ (NC–CH₂–CO₂⁻) was released and a catalytic bielectronic carboxylation of chloroacetonitrile took place. Controlled potential electrolyses confirmed the catalytic process and gave for cyanoacetic acid faradic yields up to 60% under low overpotential conditions.     

Synthesis of highly functionalized 9,10-anthraquinones

The reaction of dialkyl acetylenedicarboxylates with ethyl 9,10-dihydro-2-methyl-9,10-dioxo-anthracen-1-yl-carbamoyl-formate in the presence of triphenylphosphine produces dialkyl 2,5-dihydro-1-(9,10-dihydro-2-methyl-9,10-dioxoanthracen-1-yl)-4-ethoxy-5-oxo-1H-pyrrole-2,3-dicarboxylates in fairly good yields.     

1-苯氧基-91,0-蒽醌的合成与光致变色性研究

报道了一种新的光致变色化合物1-苯氧基-91,0-蒽醌的合成方法,具有较高产率。目标化合物的紫外-可见光谱在387,3192,81 nm处有3个等吸光点,在波长472 nm处吸收变化明显,证明了1-苯氧基-91,0-蒽醌具有光致变色性,且光致变色效果较好。     

Microbial Degradation of 9,10-Phenanthrenedione

Pseudomonas sp. strain PD1 capable of utilizing 9,10-phenanthrenedione as the sole source of carbon and energy for growth was isolated from a bacterial community previously enriched from a highly PAH-contaminated soil. Diphenic acid and phthalic acid were identified as major metabolic intermediates. Phthalic acid accumulates during 9,10-phenanthrenedione degradation and possibly acts as a toxicant to the bacteria when a defined concentration is exceeded.     

Synthesis and properties of 1,5- and 1,8-dichloro-substituted poly(9,10-dihydroanthracene-9,10-diylidene)s

Two new dichloro-substituted poly(9,10-dihydroanthracene-9,10-diylidene)s were prepared by self-condensation of 1,5-dichloroanthrone and 1,8-dichloroanthrone. The bromination and thermal and semiconductive properties were investigated.     

Optimization of the electropolymerization of 1-amino-9,10-anthraquinone conducting films from aqueous media

The optimum conditions for the electrochemical preparation of poly(1-amino-9,10-anthraquinone), PAAQ, films in environmentally safe aqueous solutions were investigated. The conducting polymer films were prepared by electrochemical oxidation of 1-amino-9,10-anthraquinone, AAQ, in sulfuric acid solutions in the potential range from 0.0 to +1.3 V. The influence of scan repetition, scan rate, and monomer concentration on the formation process and the properties of the polymer film were studied. The electrochemical response of the formed polymer film was investigated in both aqueous and non-aqueous media. The polymer films were found to be stable in aqueous acidic media. In non-aqueous solutions, like acetonitrile, dimethyl sulfoxide and dioxin, the polymer films showed remarkable degradation. The best electrochemical response of the PAAQ films was found to be in the potential range between +0.3 and +0.9 V. The presence of quinone units in the polymer film chain suggests promising applications of these conducting polymers in lightweight (rechargeable) batteries, electrochromic display devices, and biosensor and corrosion protection.     

10-(异丙基-2-醇)-9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物的合成

以9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物(DOPO)和丙酮为原料,合成10-(异丙基-2-醇)-9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物。考察了原料摩尔比、反应温度和反应时间对产物收率的影响。结果表明,较优工艺条件为:n(丙酮)∶n(DOPO)=12∶1,反应温度为50℃,反应时间为30 min时,DOPO的转化率为99%,目标产物收率为90%。     

Electrocatalytic carboxylation of 2-amino-5-bromopyridine with CO2 in ionic liquid 1-butyl-3-methyllimidazoliumtetrafluoborate to 6-aminonicotinic acid

A new electrochemical procedure for the electrocatalytic carboxylation of 2-amino-5-bromopyridine with CO₂ in ionic liquid, 1-butyl-3-methyllimidazolium tetrafluoborate (BMIMBF₄), to 6-aminonicotinic acid was investigated for the first time. The experiments were carried out in three electrodes undivided cell under mild conditions, and the use of volatile and toxic solvents and catalysts, as well as any other additional supporting electrolytes, was avoided. The electrochemical reduction behavior of 2-amino-5-bromopyridine in BMIMBF₄ had been studied by cyclic voltammetry with a reduction peak at −1.6 V (vs. Ag). 6-Aminonicotinic acid was obtained in 75% yield and 100% selectivity, under the optimized condition. Moreover, the ionic liquid was successfully recycled.     

2，2＇[蒽-9，10-二（亚甲硫基）]-1，1’-二（对甲苯基）二乙醇的合成及其对Sr2＋的识别

以对甲基苯乙酮为原料合成了2,2’-[蒽-9,10-二（亚甲硫基）]-1,1’-二（对甲苯基）二乙醇,其结构经IR、1HNMR和MS表征。通过紫外吸收光谱法考察了该化合物对金属阳离子的识别性能,结果表明,该化合物对Sr。＋具有高选择识别能力。讨论了主客体识别作用的机制。     

Synthesis and characterization of highly soluble 9,10-diphenyl-substituted poly(2,6-anthracenevinylene)

We report the synthesis and optoelectronic properties of highly soluble poly(9,10-bis(3′,4′-di(2″-ethylhexyloxy))phenyl)-2,6-anthracenevinylene) (HSM-PAV). The key intermediate for the synthesis of HSM-PAV is 2,6-dimethyl-9,10-dibromoanthracene, and the high solubility of HSM-PAV is from the incorporation of lateral 3,4-di(2-ethylhexyloxy)phenyl moieties into the 9,10-positions of anthracene units. The increase of side alkyloxy groups endows HSM-PAV with higher molecular weight (M_n = 3.2 × 10⁴) and better electroluminescence performances (L_max = 590 cd/m², LE_max = 0.27 cd/A) compared with the poly(2,6-anthracenevinylene) with lateral monoalkyoxy moieties (M_n = 1.9 × 10⁴, L_max = 340 cd/m², LE_max = 0.17 cd/A). The electrical conductivity of doped HSM-PAV film with iodine is 5 × 10⁻² S cm⁻¹ that is several order higher than that of doped 9,10-anthracene-based polymers, further demonstrating that linkage position has a dramatic effect on the optoelectronic properties of anthracene-based conjugated polymers.     

9,10-蒽醌-2-磺酰-L-氨基酸的合成

合成了5种9,10-蒽醌-2-磺酰-L-氨基酸化合物,其结构经过紫外光谱、红外光谱、质谱、核磁共振氢谱和元素分析确证。经过对合成条件的摸索和探讨,找到了最佳的分离和纯化条件。     

1-甲氧基-9,10-二苯基蒽的制备及在农业上的应用

以蒽醌、溴苯等为主要起始原料,通过蒽的1位及9、10位取代,合成了1-甲氧基-9,10-二苯基蒽(MDPA)。改进和优化了各步合成工艺条件:在汞盐催化下,当反应温度为130℃,发烟硫酸浓度为20%~25%,反应时间为1.5 h时,中间体蒽醌-1-硫酸钾收率为53.7%;采用苯基锂与1-甲氧基蒽醌加成后,直接用SnC l2的乙酸水溶液还原,产品收率为68.9%。测试了MDPA在PE农膜中的转光性质。结果表明,将MDPA掺入PE树脂中而形成的蓝光膜能在波长438 nm处光致发光,该波长与植物光合作用所需的蓝光区相吻合;与普通农膜相比,蓝光膜可促进作物生长,使白菜、茼蒿、莴笋等蔬菜产量增加20%左右。     

Electrochemical preparation and characterization of poly(1-amino-9,10-anthraquinone) films

Poly(1-amino-9,10-anthraquinone), PAAQ, films were prepared by electrochemical oxidation of the monomer, AAQ, in acetonitrile using LiClO₄ as supporting electrolyte. The influence of scan repetition, scan rate and monomer concentration on the formation of polymer film was studied. The electrochemical behavior of the formed polymer films was investigated in both non-aqueous and aqueous media. The prepared films were found to be more stable in organic solvents than in aqueous solutions. The investigated organic solvents are methanol, ethanol, acetone, carbon tetrachloride, benzene, and chloroform. The polymer film shows electrochemical response in both non-aqueous and aqueous media. In non-aqueous solutions it has a wide potential range of electroactivity (from −1.5 to +1.3 V). In aqueous media the polymer film shows electrochemical response in the potential range between −0.3 and +1.3 V only. The presence of quinone units suggests potential applications in diverse areas such as electrocatalytic processes and lithium ion batteries.     

Electrochemical characteristics and dyeing properties of selected 9,10-anthraquinones as mediators for the indirect cathodic reduction of dyes

Substituted 9,10-anthraquinones were characterised using cyclic voltammetry for their potential to serve as mediators for the indirect cathodic reduction of dispersed sulphur dyes, vat dyes and indigo. Besides characterisation of the electrochemical behaviour, the compounds were assessed in model dyeing experiments for chemical stability and staining of cotton fabric. 1,2-, 1,4- and 1,8-dihydroxy-9,10-anthraquinones exhibited negative mid-point potential ((E_p)_d + (E_p)_a)/2 of −713 to −820 mV (vs. Ag/AgCl, 3 M KCl). Under model dyebath conditions staining of cotton fabric occurred. 9,10-anthraquinone-1,5-disulfonate and 9,10-anthraquinone-2,6-disulfonate both imparted low staining to cotton; their mid-point potentials (−698 mV and −475 mV, respectively) limit their applicability to the reduction of sulphur dyes. Dihydroxy substituted 9,10-anthraquinone-sulfonates exhibited low staining owing to their good solubility. The mid-point potentials of 1,4-dihydroxy-9,10-anthraquinone-2-sulfonate and 5,8-dihydroxy-9,10-anthraquinone-2-sulfonate were only −618 mV and −675 mV respectively. Of the 9,10-anthraquinoids studied, 1,2-dihydroxy-9,10-anthraquinone-3-sulfonate (C.I. Mordant Red 3) could be identified as the most promising reversible redox couple, displaying a mid-point potential of −848 mV, low staining of cotton fabric and sufficient chemical stability under dyebath conditions.     

Electrochemical preparation of peroxodisulfuric acid using boron doped diamond thin film electrodes

We have investigated the electrochemical oxidation of sulfuric acid on boron-doped synthetic diamond electrodes (BDD) obtained by HF CVD on p-Si. The results have shown that high current efficiency for sulfuric acid oxidation to peroxodisulfuric acid can be achieved in concentrated H₂SO₄ (>2 M) at moderate temperatures (8-10 °C). The main side reaction is oxygen evolution. Small amounts of peroxomonosulfuric acid (Caro's acid) have also been detected. A reaction mechanism involving hydroxyl radicals, HSO₄⁻ and undissociated H₂SO₄ has been proposed. According to this mechanism electrogenerated hydroxyl radicals at the BDD anode react with HSO₄⁻ and H₂SO₄ giving peroxodisulfate.     

磷酸酯类阻燃剂DOPO合成工艺的改进

为解决因采用高温反应所引起的9，10-二氢-9-氧杂-10磷杂菲-10氧化物（DOPO）。产品质量问题，首先采用在170-180℃下、8h反应的一步法合成中间产物6-氯-6氢-二苯并[c，e][1，2]-氧杂膦（CDOP），以简化反应过程，并减少副反应的发生，然后在过量水存在的条件下充分进行水解反应，并采用有机溶剂对水解产物进行提纯，以避免使用高真空；最后在116—125℃的低温进行的脱水反应。以防止产物发生分解，从而得到高纯度、高收率的产品DOPO。     

Electrochemical reduction of butyraldehyde in the presence of CO2

The reduction of butyraldehyde in nominally dry acetonitrile has been investigated using cyclic voltammetry and in situ FTIR spectroelectrochemistry. The major products (butanol, enolate anion equilibrium species and the aldol) have been identified, the formation of which may be attributed to the electrochemical formation of the highly basic radical anion that abstracts protons form free butyraldehyde ultimately resulting in the well-known aldol condensation reaction. However, in the presence of electrophilic CO₂, the aldol and enolate formations are suppressed, and to account for this observation a reaction scheme is proposed involving the nucleophilic coupling of the enolate carbanion with CO₂ to form the carboxylate.     

Synthesis of soluble poly(9,10-dihydrophenanthrene-2,7-diyl)s. A new class of luminescent poly(p-phenylene)s with ethylene type bridges

Poly(9,10-dihydrophenanthrene-2,7-diyl)s with -OSi(R)₂(R′) groups at the 9,10-positions were synthesized by dehalogenative polycondensation of the corresponding monomers by using a zerovalent nickel complex. They showed number average molecular weights (M_n's) of 9800-69,000 and high quantum yields (62%-quantitative) in photoluminescence. Palladium catalyzed copolymerization of 2,7-dibromo-9,10-dihydrophenanthrene having -OCH₃ or -OSi(R)₂(R′) groups at the 9,10-positions with diethynyl- or diboronic-aromatic compounds also gave photoluminescent polymers with high quantum yields.     

Selective Synthesis of Glyceryl Tris[9,10-(threo)-dihydroxyoctadecanoate]

Elaborating novel triacylglyceride (TAG) based polyester hyperbranched unimolecular encapsulating agents represents an original and promising approach to the selective delivery of hydrophobic biologically active compounds. However, selective modification of double bonds in unsaturated TAG to obtain corresponding pure polyhydroxy derivatives with high yields is still a big challenge. Two novel approaches to synthesize the glyceryl tris[9,10-(threo)-dihydroxyoctadecanoate] were proposed and tested: (1) via the bromination and nucleophilic substitution of secondary halide functions by oxyacetyl groups followed by the hydrolysis of acetyls, and (2) direct transformation of the double bonds by the reaction with peroxoformic acid in an excess of formic acid, and the removal of formyl protective groups. Glycerol trioleate and natural olive oil were used as starting materials. The first synthetic route allowed for successful preparation of the corresponding polyhalide and polyoxyacetyl products; however, a more effective final deacetylation procedure is required. The second proposed approach showed a very good reproducibility in obtaining hydroxy-oxyformyl derivatives. The optimal conditions of the reaction involve the use of diethyl ether as a cosolvent and stirring at room temperature for 30 min. To remove the formyl groups, three original procedures using organic solvent medium at room temperature were proposed: in the presence of cesium carbonate in chloroform–methanol mixture, and two methods using hydrochloric acid in chloroform–methanol mixture or in acetone. All three methods were efficient to carry out the deformylation; nevertheless, TAG esters remained stable only with 15–17 % hydrochloric acid in acetone. Simple isolation procedures and high overall yields (95.6 and 94.9 % for both triolein and olive oil, respectively) allow considering the second approach as a promising method to obtain threo-polyhydroxy derivatives from unsaturated TAG.