稀土与不同端基直链聚醚配合物的合成及其NMR研究

合成了稀土高氯酸盐分别与一缩二乙二醇二甲醚(EO_2Me_2)和一缩二乙二醇-二-(邻甲氧基苯基)醚[EO_2(MeOP)_2]形成的两系列17种新的配合物,经元素分析、IR、NMR表征,确定配合物组成为Ln_3(ClO_4)_9(EO_2Me_2)_5·18H_2O(Ln=La,Pr,Nd)和Ln(ClO_4)_3EO_2Me_2·8H_2O(Ln=Sm,Eu,Gd,Tb,Dy,Ho,Er,Yb,Y)及Ln(ClO_4)_3EO_2(MeOP)_2·6H_2O(Ln=La,Pr,Nd,Eu,Gd).讨论了它们的NMR及光谱等性质,研究了不同端基直链聚醚对配位作用的影响。     

希土高氯酸盐与直链醚配合物的合成与性质

本文首次合成了十五种希土高氯酸盐与三缩四乙二醇(EO_4)的配合物。很有意义地见到金属:EO_4的摩尔比均为1:2。通过元素分析、摩尔电导、热重一差热分析及红外光谱等表征,确证其组成为Ln(EO_4)_2(ClO_4)_3·nH_2O(Ln=La-Gd,n=2;Ln=Tb-Lu,Y,n=3)。文中探讨了不同溶剂、不同阴离子等对配位性质的影响,并与相应的冠醚配合物进行了比较。     

三元体系Ln(ClO4)3-4-ClCH2COAp-H2O(30℃)的相平衡研究(Ln=La,Sm,Er)

我们测定了三元体系 Ln(ClO_4)_3—4-ClCH_2COA_p—H_2O(Ln=La,Sm,Er)存30℃时的溶度及饱和溶液的折光指数,绘制了相应的溶度图和饱和溶液的折光指数曲线图.体系的溶度曲线和折光指数曲线均由四支组成,分别与4-ClCH_2COA_p、Ln(4-ClCH_2COAp)_3(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,8;Er,4)、Ln(4-ClCH_2COAp)_2(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,6;Er,4)和 Ln(ClO_4)_3·nH_2O(Ln=La,n=8;Sm,9;Er,6)相对应,两类配合物均为固液异组成化合物.     

希土与芳香胺及其氮氧化物形成配合物的研究 X.镧系元素高氯酸盐与2,2''''—二喹啉甲烷固态配合物的合成及性质

本文报道了除钜以外的镧系元素高氯酸盐与2,2′-二喹啉甲烷(Biqm)所形成的新型固体配合物Ln(Biqm)_2(ClO_4)_3·nH_2O(n=0～4)的合成方法,以及通过元素分析、红外光谱、紫外光谱、差热-热重分析、X射线物相分析和电导测定等手段,对配合物的组成和性质所进行的研究结果,推测该类配合物的结构式为:[Ln(Biqm)_2ClO_4]·(ClO_4)_2·nH_2O。     

稀土元素与二缩三乙二醇二甲醚配合物的合成、NMR及其构象研究

合成了15种新的镧系高氯酸盐和二缩三乙二醇二甲醚的配合物,证明其组成为 Ln(ClO_4)·EO_3Me_2·5H_2O(Ln=La—Lu,Y).由于端基的改变明显影响配位能力,因而引起配合物组成及物化性质等一系列变化.本文尝试以~C NMR 弛豫速率法获取直链聚醚配合物中的结构信息,并探讨其构象问题,实验证明成配后配体采取全 TGT 构象.     

三元体系LaX3—PIAP—H2O（X^—=ClO4^—,NO3^—,Cl^—）（30℃）的相平衡

测定了三个三元体系LaX_3-PIAP-H_2O（X~- = ClO_4~-，NO_3~-，Cl~-， PIAP为4－（邻苯二甲酰基）亚基安替比林）在30℃时的溶解度。研究发现La (NO_3)_3-PIAP-H_2O和LaCl_3-PIAP-H_2O体系均为简单共饱型；La(ClO_4)_3- PIAP-H_2O体系有一个新固相形成，其组成为La(PIAP)_3（ClO_4）_3·4H_2O和体 系均为简单共饱型；La(ClO_4)_3-PIAP-H_2O体系的相平衡研究结果，合成了相应 的镧系配合物Ln(PIAP)_3(ClO_4)_3·4H_2O(Ln = La, Pr, Nd, Sm, Gd, Yb)，通 过化学分析、元素分析TG-DTG'IR谱和密度对化合物进行了表征。     

镧系双亚砜络合物的研究(Ⅲ)——镧系高氯酸盐的双(正-辛基亚砜)乙烷络合物

合成了12个镧系高氯酸盐的高熔点双(正-辛基亚砜)乙烷(α-BOSE)络合物。元素分析、摩尔电导、红外光谱、热谱和电子光谱等研究证实,络合物组成为:Ln(ClO_4)_3(BOSE)_3·nH_2O(Ln=La、Sm、Gd、Ho、Tm、n=0;Ln=Ce、Pr、Nd、Eu、n=2)和Ln_2(ClO_4)_6(BOSE)_5·4H_2O(Ln=Dy、Er)以及Yb(ClO_4)_3(BOSE)_2·2H_2O。络合物中的BOSE均通过>S=O基团的氧原子与镧系离子结合。随镧系离子半径减小,络合物的配位数、共价参数和热稳定性等均有减小倾向。     

希土冠醚类配合物的研究--Ⅹ.轻希土硝酸盐与二苯并-24-冠-8固态配合物的合成及性质

在乙腈介质中制得了2:1型固态配合物[Ln(NO_3)_3]_2·DB24C8.2H_2O(Ln=La、Pr)和3:2型固态配合物[Ln(NO_3)_3]_3(DB24C8)_2·3H_2O(Ln=Nd,Sm,Eu)。研究了冠醚及其配合物的红外光谱、紫外光谱、热稳定性及X—射线粉末衍射等性质,观察了它们在常见有机溶剂中的溶解情况,在乙腈中的电导测定结果表明这些配合物均为非电解质。     

希土二氯醋酸盐与邻菲罗啉(phen)混配配合物合成和表征

本文采用一种新的合成方法在水、乙醇和四氢呋喃混合溶剂中合成了6种希土二氯醋酸盐与邻菲罗啉(phen)混配配合物,通过元素分析、红外光谱、差热-热重和紫外光谱等分析测试手段研究了配合物的性质,并确定配合物的组成为:Ln(CCl_2HCOO)_3(phen)_2·2H_2O[Ln=Gd、Tb、Er、Yb]和Ln(CCl_2HCOO)_3(phen)_2·H_2O·C_2H_5OH[Ln=Pr、Nd].     

三氯醋酸稀土与1,10—邻菲绕啉配合物的合成与性质研究

关于稀土与1,10-邻菲绕啉(phen)等杂环胺双齿配合物的研究,人们发现当阴离子为Cl~-、NO_3~-时,稀土与杂环胺的配合比为1:2;当阴离子为ClO_4~-时,配比为1:3,1:4;而当阴离子为醋酸根或卤代醋酸根时,配比均为1:1。文献曾报道了在萃取溶液中存在Ln(TCA)_3(phen)_2配合物。本文合成并表征了Ln(TCA)_3(phen)_2·nH_2O(n=0,Ln=La、Nd;n=2,Ln=Gd、Er)的固态配合物,说明以三氯醋酸根(TCA~-)为阴离子时,同样存在Ln:phen=1:2的固态配合物。     

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.