一种新型的糖基型紫外线吸收剂的合成和表征

<正>紫外线是太阳光谱中波长200～400nm部分的电磁波,约占太阳辐射的6%,按波长不同,又可分为UVC(短波紫外线,200～280nm)、UVB(中波红斑效应紫外线,280～320nm)、UVA(长波黑斑效应紫外线,320～400nm)3个区段,其中UVC几乎全部被大气层阻滞,对人体无法造成伤害。     

1,2-环氧丙醚基芳香酮紫外线吸收剂的微波合成和表征

以2,4-二羟基二苯甲酮、4-羟基苯乙酮(HAP)为原料分别和环氧氯丙烷反应,经微波辐照合成了两种反应性紫外线吸收剂2-羟基-4-缩水甘油醚基二苯甲酮(HEPBP)和4-缩水甘油醚基苯乙酮(EPAP)。结构采用红外光谱、核磁和质谱表征。最佳合成条件为:n(羟基芳香酮)∶n(环氧氯丙烷)=1∶3,微波功率400W,于90℃反应15min,收率分别是52.6%和58.3%。与常规合成方法比较,微波合成法能降低反应温度、大大地缩短反应时间。产物中环氧丙烷基团的引入能明显改善芳香酮类紫外线吸收剂的紫外吸收性能。     

侧链中含二苯甲酮基的聚硅氧烷的合成与结构表征

在相转移催化剂四乙基溴化铵作用下,利用2,4-二羟基二苯甲酮与烯丙基缩水甘油醚在碱性水溶液中的开环加成反应,合成了中间体4-(β-羟基-γ-烯丙氧)丙氧基-2-羟基二苯甲酮(MUV-0),将其进-步与聚甲基氢硅氧烷进行硅氢化加成反应。合成了侧链中含二苯甲酮基的聚有机硅氧烷。用元素分析、红外光谱、紫外光谱和核磁共振等仪器对中间体以及目标聚硅氧烷的结构进行了表征和测定。结果表明：中间体和聚硅氧烷在紫外光区均具有二苯甲酮衍生物特有的三条吸收谱带,对波长240～400nm的紫外光有良好的吸收作用。     

N-杂环芳基水溶性碳点全光谱紫外吸收剂的合成与应用

通过水热法制备出以含N原子的芳香化合物、柠檬酸钠和乙二胺为原料的水溶性碳点紫外吸收剂,并对不同芳香族化合物制备的碳点进行老化试验,最终筛选出具有耐老化性能的碳点(A-CDs),其中,富含—COOH、—NH₂等官能团且具有紫外全吸收性能,并进一步通过优化反应条件提高了其吸收性能。将A-CDs与聚乙烯醇(PVA)复合,形成高性能的紫外屏蔽膜。当CDs的质量分数从0.02%增加至0.1%时,紫外透过率从8%降低至3%,说明碳点能在薄膜中稳定存在。同时,碳点的加入可以降低薄膜在紫外照射下的衰老速率,维持薄膜的力学性能。     

高效液相色谱法同时测定化妆品中9种二苯甲酮类紫外吸收剂

建立同时测定化妆品中9种二苯甲酮类紫外吸收剂的高效液相色谱法.样品用乙腈溶解,经超声提取后,选择Waters Symmetry C18(250 mm×2.1 mm,5μm)色谱柱,以乙腈–0.1％甲酸溶液为流动相,梯度洗脱,采用二极管阵列检测器检测,检测波长为322 nm,外标法定量.9种二苯甲酮类紫外吸收剂的质量浓度...     

2-[2,4-二羟基苯甲酰]苯甲酸金属盐的合成、表征及其光稳定能力研究

本工作合成了多种含不同过渡金属离子的络合物——2-[2,4-二羟基苯甲酰]苯甲酸钴、镍、锰金属盐.对它们进行了详细表征和光稳定能力进行了实际评价,结果表明这类化合物有很好的光稳定能力,并指出含锰离子的络合物具有最佳光稳定能力是由于锰离子对原有的分子内氢键结构破坏最小所致.     

高效液相色谱法同时测定纺织品中11种二苯甲酮类紫外吸收剂

剪碎后的纺织品样品0.500 0g经30mL甲醇于60℃超声提取30min,冷却至室温后,取上清液用0.45μm有机滤膜过滤,采用高效液相色谱法同时测定滤液中11种二苯甲酮类紫外吸收剂的含量。以xBridge shield RP C_(18)色谱柱(250mm×4.6mm,5μm)为分离柱,用0.1%(体积分数,下同)甲酸溶液和含0.1%甲酸的甲醇-异丙醇溶液(甲醇与异丙醇体积比为7∶3)以不同比例混合的溶液为流动相进行梯度洗脱,在检测波长280nm处进行测定。11种二苯甲酮类紫外吸收剂的质量浓度均在0.5～20.0mg·L~(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为3～9mg·kg~(-1),测定下限(10S/N)为9～27mg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为87.6%～107%,测定值的相对标准偏差(n=6)为1.9%～8.3%。方法应用于33批次的防紫外线纺织产品样品的分析,4-羟基二苯甲酮在所有样品中均未检出,其他二苯甲酮类紫外吸收剂均在样品中有不同程度的检出,2-羟基-4-甲氧基二苯甲酮的检出率最高,达到了58%,质量分数在42～261mg·kg~(-1)之间。     

聚醚-紫外侧基聚硅氧烷的结构表征与膜形态

利用聚甲基氢硅氧烷(PHMS)与4-(β-羟基-γ-烯丙氧)丙氧基-2-羟基二苯甲酮(MUV-O)、α-烯基聚醚(F6)的硅氢化加成反应,合成了一种新型聚醚-二苯甲酮衍生物侧基聚硅氧烷PE-PUVSi,用红外光谱(IR)、紫外光谱(UV)、核磁共振氢谱(1H-NMR)以及原子力显微镜(AFM)等仪器对产物的结构和成膜形态进行了研究。结果表明,新合成的PE-PUVSi对波长为243.6、289.2、325.0nm的紫外光有强吸收作用。在纤维及单晶硅表面,PE-PUVSi均可成膜。但宏观上平滑的PE-PUVSi膜,微观上实则呈非均一、相分离结构,其中UV侧基以纤细尖峰分布在聚硅氧烷膜表面,而亲水性聚醚基团则卷曲堆积成峰包。     

Synthesis of a novel water-soluble polymeric UV-absorber for cotton

A water-soluble polymeric UV-absorber with polyvinylamine as backbone and benzotriazole type UV absorber as anti-UV functional group was synthesized by grafting brominated(2’-acetoxy-5’-methylphenyl)-2H-benzotriazole onto polyvinylamine. The intermediates and synthesized polymeric UV absorber were characterized by ~1H NMR,MS,IR and UV spectroscopy.The finishing properties of the polymeric UV absorber on cotton were investigated to show good UV protection property and wash fastness.     

2,4,6-Trichloro-1,3,5-triazine as an Efficient Catalyst for Synthesis of Benzopyran Derivatives under Solvent-Free Conditions

An efficient and convenient procedure has been developed for the synthesis of benzopyran derivatives by one-pot condensation of substituted salicyaldehydes and substituted 1,3-hexanediones in the presence of a catalytic amount of 2,4,6-trichloro-1,3,5-triazine (TCT, cyanuric chloride) under solvent-free conditions.     

2,4,6-三萘基-1,3,5-三嗪的合成与光谱行为

本文通过Suzuki偶联反应高效合成了两种三萘基三嗪化合物,即2,4,6-三(1-萘基)-1,3,5-三嗪(T1NT)和2,4,6-三(2-萘基)-1,3,5-三嗪(T2NT). 考察了介质的极性、温度以及THF-H₂O二元溶剂体系中的溶解性等因素对它们吸收和发射光谱行为的影响.研究发现, 由于T1NT比T2NT具有更好的分子平面性,其激发态下分子内电荷转移的程度较大,导致其在溶液中吸收光谱、发射光谱比T2NT呈现显著红移.冻结态下,分子平面性较差的T2NT显示出较短波长的发光.     

Synthesis of diiodo- and triiodoanilines by iodination of aniline with potassium dichloroiodate and preparation of 1,3,5-triiodobenzene

A new chemoselective procedure was developed for the synthesis of 2,4,6-triiodoaniline and 2,4-diiodoaniline by the reaction of aniline with potassium dichloroiodate in dilute HCl. Subsequent deamination of 2,4,6-triiodoaniline afforded 1,3,5-triiodobenzene in good yield.     

Photocatalytic self-assembled solid porphyrin microcrystals from water-soluble porphyrins: Synthesis,characterization and application

In this article, we report on the formation of a photocatalytic porphyrin crystalline structure using two oppositely charged commercially available low cost porphyrins, [meso-tetra(N-methy-4-pyridyl)porphyrin tetratosylate (TMPyP) and zinc-tetrakis(4-sulfonatophenyl)porphyrin (Zn-TPPS)], by self-assembly at room temperature without acidification. Using optical microscopy, the crystals were determined to have a length of 30–55 μm and width of 2–50 μm, depending on the molar ratio of the porphyrins in the starting solution. The porphyrin crystals were characterized by means of powder X-ray diffraction and UV–Vis, fluorescence, and optical microscopic techniques. The UV–Vis absorbance spectrum of the crystalline structure is different than those of the monomer solutions, involving a broadened Soret band that is split into two blue-shifted and red-shifted peaks and broadened red-shifted Q-bands. The crystals exhibit a different emission spectrum from those of the porphyrin solutions in that they are red-shifted, split, and show a dramatic decrease in intensities. A hypothetical model for the crystal structure of the porphyrin crystals is developed. Illumination of the crystals in a 2,4,6-trinitrotoluene solution with a tungsten lamp results in TNT reduction to 1,3,5-trinitrobenzene and 4-amino-2,6-dinitrotoluene.     

Trisubstituted 1,3,5-Triazines. 6. Synthesis of 2,4,6-Tris(acetonyl)-1,3,5-triazine

Acylation of 2,4,6-tris(tert-butoxycarbonylmethyl)-1,3,5-triazine with acetic anhydride in the presence of lithium hydride with subsequent removal of the tert-butoxycarbonyl groups with trifluoroacetic acid leads to 2,4,6-tris(acetonyl)-1,3,5-triazine, the cyclic analog of -cyanoacetone. The special spectral features of this compound compared with triazines obtained previously are discussed.     

Greener approach toward synthesis of biologically active s-Triazine (TCT) derivatives: A recent update

The greener methodology to synthesize s-triazine derivatives (also known as TCT) is described, including synthesis through microwave, ultrasound, and solvent-free conditions. This review mainly focuses on reactions of TCT (2,4,6-trichloro-1,3,5-triazine) with various substituents having amine and hydroxy functionalities to give corresponding triazine derivatives under a greener approach. The results of reactions indicate that, unlike classical methods, green methods result in better yields of the product, through a rapid reaction, under mild reaction conditions, and by easy workup procedures.     

Adducts of lanthanide β-diketonates with 2,4,6-tri(2-pyridyl)-1,3,5-triazine: Synthesis,structural characterization,and photoluminescence studies

Adducts of lanthanide β-diketonates of the general formula LnL₃(TPTZ) were synthesized and structurally characterized by single crystal X-ray diffraction [Ln = Eu³⁺, Tb³⁺, Er³⁺; L is the conjugate base of dibenzoylmethane (DBM), 1-benzoylacetone (BA), thenoyltrifluoroacetone (TTA), or 4,4,4-trifluoro-1-phenyl-1,3-butanedione (BTFA); TPTZ = 2,4,6-tri(2-pyridyl)-1,3,5-triazine, a rigid Lewis base with a large π system]. The lanthanide ion in each of these complexes is nonacoordinate with six β-diketonate oxygen atoms and three TPTZ nitrogen atoms, forming a coordination polyhedron best describable as a monocapped square antiprism. Characteristic red, green, and near infrared luminescence was observed for the Eu³⁺, Tb³⁺, and Er³⁺ complexes, respectively. All complexes showed significantly enhanced luminescence quantum yields when compared with the corresponding aqua analogues, with one of the Eu³⁺ complexes displaying a quantum yield of 69.7% in chloroform.     

Microwave Assisted Synthesis of 2,4,6-Triarylamino-1,3,5-triazines as Potential UV Absorbent

Abstract

2,4,6-Triarylamino-1,3,5-triazines was synthesized in a few minutes by reaction of cyanuric chloride with aromatic amines under microwave irradiation. This method is featured with rapid reaction, convenient operation, high yield, and clean. UV-absorption was tested for each compound.     

One-Pot Formylation and Dimerization of p-Alkyl Phenols Using DCMT-Activated DMSO

Dimerization and formylation of p-alkyl-substituted phenols have been successfully achieved in one pot, using 2,4-dichloro-6-methoxy[1,3,5]triazine (DCMT)-activated dimethylsulfoxide. Similarly, the d5-labeled products have been prepared in high selectivity. To the best of our knowledge, the products are of new skeletons, which have not been reported to date. A plausible mechanism is proposed based on the experiments.