Catalytic Synthesis of Hexyl-naphthalene over H-type Zeolites

H-type zeolites（ HY, Hβ, and HM） were synthesized and characterized by XRD, NH3-TPD, and Py-IR. Selectively catalytic alkylation of naphthalene with n-hexanol to hexyl-naphthalene over the zeolites was carried out. The experimental results show that the catalytic activities of the zeolites are mainly determined by their acid properties and pore structures. The larger the pore diameter is, the higher the catalytic activity is. NH3-TPD profiles show that Hβ and HM have lower acid strengths than HY. HY has both the highest activity and highest selectivity for the hexylnaphthalene. Higher reaction temperatures and longer reaction time are beneficial to the production of β-hexyl-naphthalene over the HY zeolite.     

New photochromic diarylethenes bearing a condensed aromatics moiety

A new class of diarylethenes based on a hybrid structure of naphthalene and thiophene have been developed and their properties including photochromism, fatigue resistance, and fluorescence have been investigated. The condensed aromatic naphthalene was connected directly to the central cyclopentene ring as an aryl moiety and available to participate in the photoinduced cyclization reaction. All of these compounds have exhibited good photochromism, notable fatigue resistance, and obvious fluorescence photo-switches in both solution and polymer matrix. Nevertheless, significantly different properties have been observed among these diarylethenes, which may be attributed to the effect of different substituent groups. Compared with the analogs bearing other six-membered aryl unit, the naphthalene moiety is more conducive, which leads to higher molar absorption coefficient and blue shift of the absorption maximum.     

Determination of histamine and histidine by capillary zone electrophoresis with pre-column naphthalene-2,3-dicarboxaldehyde derivatization and fluorescence detection

A rapid and sensitive method was developed for the simultaneous determination of histamine and histidine by capillary zone electrophoresis with lamp-induced fluorescence detection. A fluoregenic derivatization reagent, naphthalene-2,3-dicarboxaldehyde (NDA) was successfully applied to label the histamine and histidine respectively. The derivatization conditions and separation parameters including pH and concentration of electrolyte and sample injection were optimized in detail. The optimal derivatization reaction was performed with 1.0 mM NDA, 20 mM NaCN, and 20 mM borate buffer, pH 9.1 for 15 min. The separation of NDA-tagged histamine and histidine could be achieved in less than 200 s with 40 mM phosphate buffer (pH 5.8) as the running buffer. The detection limits for histamine and histidine were 5.5 x 10(-9) and 3.8 x 10(-9) M, respectively (S/N = 3). The relative standard derivations for migration time and peak height of derivatives were less than 1.5 and 5.0%, respectively. The method was successfully applied to the analysis of histamine and histidine in the P815 mastocytoma cells and the beer samples.     

An Alternative Synthesis of the Dopaminergic Drug 2‐Amino‐1,2,3,4‐tetrahydronaphthalene‐5,6‐diol (5,6‐ADTN)

Racemic 2‐amino‐1,2,3,4‐tetrahydronaphthalene‐5,6‐diol (5,6‐ADTN; 4 ) was synthesized from 5,6‐dimethoxynaphthalene‐2‐carboxylic acid ( 14 ) in four steps (60% overall yield; Scheme). The crucial steps of the synthesis are Birch reduction of 14 to the valuable synthon 15 , Curtius reaction and carbamate formation ( 16 ), hydrogenolysis ( 17 ), and demethylation to the biologically active hydrobromide salt 18 of 4 .     

Unsteady state behavior of CO oxidation over a supported Pt catalyst in the millibar range

The alkylation of naphthalene with isopropanol was investigated over a HY (Si/Al=4) zeolite under the following conditions: flow reactor, liquid phase with decalin as solvent, 623 K, 40 bar. Despite complete filling of the zeolite pores by coke during the first hour of reaction, the rate of formation of isopropylnaphthalene remained very high. This is due to the development of a new reaction process involving transalkylation between the polyisopropyl naphthalenes entrapped in the pores and naphthalene followed by the realkylation of the former compounds with isopropanol.     

Spectrophotometric determination of nitrate and nitrite in soil and water samples with a diazotizable aromatic amine and coupling agent using column preconcentration on naphthalene supported with ion-pair of tetradecyldimethylbenzylammonium and iodide

Composite diazotization-coupling reagents containing sulfanilamide (SAM), sulfapyridine (SP) or sulfathiazole (ST) as the diazotizable aromatic amines and sodium 1-naphthol-4-sulfonate (NS) as the coupling agent using column preconcentration on naphthalene-tetradecyldimethylbenzylammonium(TDBA)-iodide adsorbent have been used for the spectrometric determination of trace nitrate and nitrite in soil and water samples. Nitrite ion reacts with SAM in the pH range 2.0–5.0, SP in the pH range 2.0–2.5 and ST in the pH range 2.0–3.3 in HCl medium to form water-soluble colourless diazonium cations. These cations were coupled with NS in the pH range 9.0–12.0 for the SAM system, 9.6–12.0 for the SP system and 8.5–12.0 for the ST system to be retained on naphthalene-TDBA-I material packed in a column. The solid mass is dissolved from the column with 5 ml of dimethylformamide and the absorbance is measured spectrometerically at 543 nm for SAM-NS, 533 nm for SP-NS and 535 nm for ST-NS. Nitrate is reduced to nitrite by a copper-coated cadmium reductor column and the nitrite is then treated with the diazotization-coupling reagent by column preconcentration. The absorbance due to the sum of nitrate and nitrite is measured and nitrate is determined by difference. The calibration graph was linear over the range 2–40 ng NO₂⁻-N ml⁻¹ and 1.5–30 ng NO₃⁻-N ml⁻¹ in aqueous samples for the SAM and ST systems and 2–48 ng NO₂⁻-N ml⁻¹ and 1.5–36 ng NO₃⁻-N ml⁻¹ in aqueous samples for the SP system, respectively. The sensitivity, accuracy and precision of the systems decreased in the order STSAMSP. The detection limits were 1.4 ng NO₂⁻-N ml⁻¹ and 1.1 ng NO₃⁻-N ml⁻¹ for SAM, 1.6 ng NO₂⁻-N ml⁻¹ and 1.2 ng NO₃⁻-N ml⁻¹ for SP, and 1.0 ng NO₂⁻-N ml⁻¹ and 0.75 ng NO₃⁻-N ml⁻¹ for ST, respectively. The preconcentration factors are 8, 5 and 6 for SAM-NS, SP-NS and ST-NS, respectively. Interferences from various foreign ions have been studied and the methods have been applied to the determination of ng ml⁻¹ levels of nitrite and nitrate in soil and water samples. The mean recovery was 95–102% for all three systems.     

可溶性侧链含萘聚酰亚胺的合成与性能

以萘甲醛和2,6-二甲基苯胺或苯胺为原料合成了2种含萘的二胺单体, 进一步与二苯醚四酸二酐(ODPA)经高温溶液缩聚, 得到2种侧链含萘的聚酰亚胺, 对聚合物进行了核磁共振谱、 傅里叶变换红外光谱及溶解性、 耐热性、 憎水性、 机械性能等结构与性能的测试. 结果表明, 含醚侧链含萘的聚酰亚胺具有优异的溶解性, 良好的耐热性, 较好的憎水性与机械性能. 另外, 通过静电纺丝的方法制备了侧链含萘的聚酰亚胺纤维, 研究了纤维的形貌与憎水性.     

基于杯[4]芳烃的银离子荧光探针的合成及性能

合成了25,27-二羟基-26,28-二{3-[N-(2-萘基)-2-硫代乙酰胺]丙氧基}-5,11,17,23-四叔丁基杯[4]芳烃(2), 并利用荧光光谱考察了其在乙醇-水混合溶液中对Ag⁺的光谱选择性. 结果表明, 含有S₂O₂结合位点的探针分子2对Ag⁺具有良好的选择性. 通过荧光光谱连续滴定测得探针分子2-Ag⁺体系的猝灭常数为3.39×10³ L/mol, 探针分子对Ag⁺的检出限可达2.34×10^-7 mol/L. 在实际的Ag⁺检测中, 探针分子2具有一定的应用前景.     

A simple naphthalene-based colorimetric sensor selective for acetate

A new naphthalene based receptor (L) has been designed and synthesized which shows a remarkable color change from colorless to pink on selective binding with acetate. The anion recognition property of the receptor via hydrogen bonding interactions is monitored by UV-vis, fluorescence, and ¹H NMR titrations. It is observed that in each case, the receptor shows a specific selectivity toward the acetate ion over other interfering anions. Thus, a significant bathochromic shift in UV-vis spectrum with a sharp pink color in ‘naked-eye’ makes the receptor suitable for the detection of the acetate ion.     

Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.