浅谈分子对称性中独立的对称元素

通过图示和矩阵两方面来阐述独立的对称元素和非独立的对称元素之间的区别与联系,利用比较法帮助读者正确理解独立对称元素的内涵。     

浅谈仪器分析实验教学的实践和体会

为帮助学生深刻领会仪器分析理论基础知识,高效掌握有关实验内容,培养学生动手能力、观察能力和团队协作精神,增强实验教学效果,我们以紫外-可见分光光度法及荧光分光光度法实验教学为例,进行了一段时间的摸索。通过调整教学内容、强化理论知识与实验联系、归纳仪器操作步骤、注重细节培养等措施,提高了仪器分析实验教学质量,取得了较好的效果。学生完成基础实验后,能自由运用所学知识,独立设计实验方案,获得所需实验结果。     

思维导图在仪器分析实验教学中的应用——以电化学分析实验为例

在电化学分析实验教学中引入思维导图,探讨了思维导图在仪器分析实验教学中的应用方法及效果评价。实验原理的教学依托“比较与对比图”和“逻辑思维图”,强调相关方法原理之间的联系,突出新方法的特点;实验步骤则以清晰易懂的“流程图”方式呈现。教学实践表明,思维导图有利于学生对实验基本原理的理解和掌握,提高了学生的实验兴趣,促进了学生的独立思考能力和解决问题的能力,显著提升了实验教学效果。     

大型仪器分析实验教学多层次培训体系的建立与实践

在大型仪器分析实验教学中,为了提升学生对基础知识的运用能力,提高学生的动手能力、创新能力,通过引入培训、教学双模式,建立了大型仪器多层次（即基础理论培训、上机操作技术培训和仪器功能应用培训）培训体系。实践证明这种多层次培训体系搭建了学生与专家、学者之间交流的平台。从理论讲解到操作,再到应用的多层次培训体系有效地弥补了大型仪器实验教学中单一教学模式存在的不足,可以很好地培养本科生和研究生的学习兴趣,提高学生分析问题、解决问题的科研能力,同时提升了仪器使用效率,储备了大量仪器方面的专业人才。     

仪器分析实验教学内容改革与实践

针对现行的仪器分析实验教学内容中存在的验证性实验偏多、缺少条件实验、忽视样品的预处理等问题,提出了改革方案。以提高学生的实践能力为出发点,从筛选与生产、生活联系密切的实验,重视样品的预处理和实验条件的选择,加强综合性、设计性实验,开设开放性和创新性实验,吸引学生参与教师的科研工作等方面对仪器分析实验教学内容改革进行了探讨。     

BODIPY荧光探针的合成及次氯酸检测的综合实验

有机实验和仪器分析实验是本科生阶段化学教学的重点内容，虽然现有的教学实验内容已十分丰富与完善，但缺少两者之间的融合以及与科研领域的联系。针对上述不足，我们将科学研究前沿和热点的荧光检测技术引入教学实践。实验通过对BODIPY (氟硼二吡咯)荧光染料结构的设计改良，合成一种具有快速响应、选择性高和灵敏度好的新型次氯酸荧光探针，对荧光探针结构进行表征，并测定荧光探针的荧光性质。通过对探针结构与荧光性质之间关系的研究，有助于加深学生荧光发光原理的理解。实验内容涵盖有机合成、产物仪器表征、光谱分析等方面，综合性强且易于学生操作。教学实践过程有助于培养学生的科学思维、理论与实践相结合的能力。     

仪器分析发展史在大学教学中的应用探讨

在大学仪器分析教学过程中 ,通过讲授仪器分析发展史 ,培养学生的创新能力 ,激发学生学习该课程的热情 ,使学生能更好地掌握基础原理与实验技能。介绍了仪器分析发展史在本科教学中的几种讲授方式     

高职“仪器分析及实验”循环进阶教学模式的开发与应用

通过分析"仪器分析"教学内容及教学对象的特点,针对"仪器分析"课程传统教学方法存在的弊端进行改革。从教学体系、教学内容、教学方法等多方面设计"仪器分析及实验"课程,构建出以学生为主体、基于认知规律、多层次阶梯式的教学模式,以提升学生对仪器分析方法的实际应用能力。     

“校准曲线”视角下仪器分析课程内容的提炼

仪器分析类课程涉及知识面广、理解难度大、实践能力要求高。对此，如何引入新的视角梳理和凝练教学内容、提升学习效果，值得探讨。从“校准曲线”的角度，直观地诠释灵敏度、特征浓度、特征质量、检出限、定量下限等方法学指标的意义和联系，将仪器分析诸多干扰的类型及其消除方法以校准曲线为融入点归纳共性、探寻本质、提炼思路和策略，为仪器分析课程的学习提供了“数形结合”和“应用导向”的新视角。该视角有助于知识要点融会贯通，有利于培养学生“学以致用”的意识和思维方法。     

从科研中提炼出的精细化工专业实验:新型疏水缔合聚合物的制备、表征及性能测定*

结合教师科研项目,推荐一个精细化工专业实验:疏水缔合聚合物的制备、表征及性能测定。通过该实验可以使学生掌握自由基共聚法制备聚合物的基本原理,掌握一些大型仪器的基本操作、聚合物常用的表征手段及结构分析方法,理解疏水缔合聚合物结构与性能之间深层次的理论联系。该实验项目来源于科研,服务于实践,集聚合反应、结构表征、大分子溶液理化性能测试于一体,具有综合性、前沿性、研究性等特点。本实验的开设有利于提高精细化工方向学生的专业实验水平,提升学生的综合探究素质、创新意识及动手能力。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.