多硫二硫醇烯配合物[Ni(C5S9)2]电磁学性能的研究

多硫 1 ,2 二硫醇烯能与过渡金属离子形成具有特殊平面共轭结构的稳定配合物 ,是构成有机导体或超导体的基本“砖块”[1,2 ] 。配合物的晶体结构研究表明 ,分子之间通过Ｓ…Ｓ原子ｐ轨道的重叠而存在的超分子相互作用是配合物具有高导电性的一个重要特征[3 ] 。增加分子间超分子相互作用的一个有效方法是增加配体上硫原子的个数。我们以Ｃ6Ｓ10 (图 1 )为中间体得到Ｃ5Ｓ2 -9(图2 ) ,与Ｎｉ2 + 离子配位后在四种不同阳离子作用下生成 (Ｃａｔ)2 [Ｎｉ(Ｃ5Ｓ9)2 ]型二价阴离子配合物。当这些配合物用Ｉ2 氧化时都生成了中性配位化合物 [Ｎｉ…     

含硫席夫碱安息香缩肼基二硫代甲酸甲酯过渡金属配合物的合成与表征

合成和表征了新的含硫席夫碱—安息香缩肼基二硫代甲酸甲酯 (H2 L)及与Mn(Ⅱ ) ,Co(Ⅱ ) ,Ni(Ⅱ )Zn(Ⅱ )和Cd(Ⅱ )生成的配合物 [M(HL) 2 ]。结果表明这些配合物中安息香缩肼基二硫代甲酸甲酯存在为去质子化的烯硫醇式三齿配体 ,通过甲亚胺基氮原子、醇羟基氧原子和烯硫醇硫原子配位 ,金属离子处于六配位的八面体环境。     

C—H…Cl Hydrogen Bond and π-π Interaction Based Two 3D Supramolecular Architectures of Cu(II) and Co(II) Complexes with Chiral 1,2-Bis(benzimidazol-2-yl) ethane Ligand Containing 2D Grids

合成了两个新的配合物CuLCl₂•2EtOH(1) 和CoLCl₂ (2) [L是( S , S )－1,2－二N－甲基苯并咪唑－1,2－二甲氧基－乙烷],并通过单晶X衍射确定它们的结构。配合物1中,L作为三齿[N, N, O]配体,而配合物2 中,L作为二齿[N, N]配体。这两个配合物共同的结构特点都是通过分子内氢键形成2维的格子结构,然后通过分子间的C－H···Cl型氢键和π–π堆积作用形成3维结构。     

四种新型柔性吡啶基配合物的合成、结构及配体构象与配合物结构的关系

合成了柔性配体3-吡啶甲酸-1,2-乙二酯(3-pyridinecarboxylic acid 1,2-ethanediyl ester,pcaede),并将其分别与Co盐和Hg盐进行组装,得到4个新配合物[Co(pcaede)2Cl2.2CH3CN.H2O]n(1),[Co(pcae-de)2Cl2.H2O]n(2),[Hg(pcaede)I2]n(3)和[Hg(pcaede)Br2]n(4),对其进行了元素分析、红外光谱及X射线单晶结构分析.配合物1和2为含有孔道的一维链状结构,配合物3是1D内消旋螺旋链,配合物4则是锯齿形1D链状结构.研究结果显示,孔道中填充的溶剂分子和平衡阴离子对配合物的组装有显著的影响.此外对4个配合物中配体的构象进行了理论计算.     

一种含取代异喹啉鎓离子的异马来二氰基二硫烯镍(Ⅱ)离子配合物的合成和晶体结构

二硫烯过渡金属配合物因特殊的结构和新颖的光、电、磁学等性质,多年来倍受化学家和材料学家重视[1,2].含[M(mnt)2]- (mnt为马来二氰基二硫烯,M 为 Ni、Pd、Pt和Fe等)配阴离子化合物NH4·Ni(mnt)2·H2O,发现低温下(<4.5 K)具有铁磁有序,是对二硫烯化学的新发展[3].     

四氮杂大环镍与[M(dmit)_2]~(2-)的离子对配合物[NiL][M(dmit)_2]的合成与表征

以1,3-二硫杂环戊烯-4,5-二硫醇-2-硫酮(dmit)和5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四-1,8-二烯(hmtade)或5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环十四烷(hmta)为配体合成了4个双金属的离子对配合物[NiL][M(dmit)2](L=hmtade,M=Ni(1);L=hmta,M=Ni(2);L=hmtade,M=Hg(3);L=hmta,M=Hg(4))。用元素分析、红外光谱、核磁共振氢谱、紫外-可见光谱、热重分析和循环伏安法等对它们进行了表征。研究结果表明,大环配体hmta、hmtade和配体dmit之间形成了N-H…S氢键,配阳离子均为五配位,配阴离子[M(dmit)2]2-的S对配阳离子的Ni(II)进行了配位。离子对配合物的稳定性顺序为:2134。     

二氰基二硫纶和邻菲咯啉二酮镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)配合物的电子光谱及分子内荷移跃迁

各种均一配体的金属二硫纶[1～4]、金属二亚胺[5,6]以及二硫纶和二亚胺混合配体的金属配合物[7,8],因其具有特殊的氧化还原性和光、电、磁功能,近10多年来一直受到科学家们的高度重视.笔者的兴趣在于二氰基二硫纶(mnt2-)的过渡金属配合物,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究[9～12].这些配合物不仅本身具有优异的气敏、光敏、催化等功能性,而且也是合成金属四氮杂卟啉的前驱物[13～14]和自组装有序分子聚集体的功能元件之一[15].……     

二氰基二硫纶和邻菲咯啉二酮镍（Ⅱ）,铜（Ⅱ）,锌（Ⅱ）配合物的电子光谱及分子内

各种均一配体的金属二硫纶[1～4]、金属二亚胺[5,6]以及二硫纶和二亚胺混合配体的金属配合物[7,8],因其具有特殊的氧化还原性和光、电、磁功能,近10多年来一直受到科学家们的高度重视.笔者的兴趣在于二氰基二硫纶(mnt2-)的过渡金属配合物,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究[9～12].这些配合物不仅本身具有优异的气敏、光敏、催化等功能性,而且也是合成金属四氮杂卟啉的前驱物[13～14]和自组装有序分子聚集体的功能元件之一[15].……     

1,2′-二氰基-1,2′-二硫烯镍(II)离子对配合物的合成及晶体结构和弱相互作用

二氰基二硫烯(mnt和i-mnt)的金属配合物因其结构独特并呈现出特殊的光、电和磁学等性质,多年来引起科学家们广泛的关注[1-2].特别是在含Ni(mnt)2阴离子的离子对配合物中,功能阳离子的大小和构型改变可以导致Ni(mnt)2阴离子的重叠模式和堆积方式的变化,从而影响这类配合物的物理性能[3-5].为进一步探索取代苄基吡啶鎓离子中取代基团对1,2′-二氰基-1,2′-二硫烯镍配合物的结构的影响,我们在以前工作的基础上[6-8],合成了1种新的1,2′-二氰基-1,2′-二硫镍(II)离子对配合物[Bz(Me)Py]2[Ni(mnt)2],用元素分析、红外光谱和X-射线衍射表征了其组成和结构,讨论了配合物晶体中弱的相互作用.     

二氰基二硫纶和邻菲咯啉二酮镍(II)、铜(II)、锌(II)配合物的电子光谱及分子内荷移跃迁

各种均一配体的金属二硫纶 [1～ 4 ]、金属二亚胺 [5,6]以及二硫纶和二亚胺混合配体的金属配合物 [7,8] ,因其具有特殊的氧化还原性和光、电、磁功能 ,近 1 0多年来一直受到科学家们的高度重视。笔者的兴趣在于二氰基二硫纶 (mnt2 - )的过渡金属配合物 ,以及二氰基二硫纶和α,α′-二亚胺混合配体过渡金属配合物的合成、性质、结构和电子功能研究 [9～ 12 ] 。这些配合物不仅本身具有优异的气敏、光敏、催化等功能性 ,而且也是合成金属四氮杂卟啉的前驱物 [13～ 14 ]和自组装有序分子聚集体的功能元件之一[15] 。　　最近 ,笔者合成和表征了…     

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.     

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%).     

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.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

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.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.