缩氨基(硫)脲席夫碱化合物的自发对称性破缺研究

制备了4-苯基-1-(吡啶-2-亚甲基)氨基脲(PPMSC)和4-苯基-1-(吡啶-2-亚甲基)氨基硫脲(PPMTC).用元素分析、MS、1HNMR、UV吸收光谱、X射线单晶衍射和固体CD光谱等对其进行了表征.晶体结构数据显示PPMSC属于Sohncke P212121空间群,单个分子之间通过氢键形成一个一维螺旋链状结构,沿a轴形成左手螺旋结构.固体CD光谱和重结晶实验证明,PPMSC手性晶体的形成是结晶诱导的绝对不对称合成.PPMTC的固体CD光谱和重结晶实验具有与PPMSC类似现象.     

新型有机二氟化硼配合物的合成及其荧光性能

以2,4-二羟基苯乙酮为起始原料,经4步反应合成了新型的有机二氟化硼配合物:5-甲氧基.2-(2-喹啉基)苯酚二氟化硼(5),其结构经<'1>H NMR,<,13>C NMR和IR表征.UV和FL研究结果表明:5不仅具有良好的溶液荧光,也呈现明亮的固体荧光.     

Pd2(dba)3/BINAP催化合成1,4-双-(4''''-苯胺基苯酰基)苯

以Pd2(dba)3/BINAP催化1,4-双-(4'-溴苯酰基)苯和苯胺反应,合成了1,4-双-(4'-苯胺基苯酰基)苯,其结构经UV,1H NMR,13C NMR和元素分析表征.     

5-取代-1H-1,2,4-三氮唑-3-羧酸的合成及结构表征

以5-氨基-1H-1，2，4-三氮唑-3-羧酸为原料，经重氮化反应和Sandmeyer反应得到5-X(X=Cl，Br，I，CN)-1H-1，2，4-三氮唑-3-羧酸，通过元素分析、UV，IR，1H NMR和MS对所有产物的结构进行了表征。     

5-卤代-1H-1,2,4-三氮唑-3-羧酸乙酯及其衍生物的合成

以5-氨基-1H1,2,4-三氮唑-3-羧酸乙酯为原料,经Sandmeyer反应合成了5-X-1H-1,2,4-三氮唑-3-羧酸乙酯(X=C1,Br,I)(1a-1c),1a-1c再分别与α-2′,4′-二氟苯乙酮反应合成了3个5-卤代-1-1H-1,2,4-三氮唑-3-羧酸乙酯衍生物(2a-2c),其结构通过元素分析,IR,UV和^1H NMR进行了表征。     

新型偶氮化合物的合成及其光学性质

以咔唑和苯酚为原料,经重氮和偶合反应合成了一种新型偶氮化合物--N-对(4-羟基苯偶氮基)苯基-3,6-二(叔丁基)咔唑(4),其结构经1H NMR和13C NMR表征.4的 UV和固体荧光光谱研究结果表明,4具有较好的光学活性.     

新型三唑基咔唑衍生物的合成及其光学性质

合成了一种新型的三唑基咔唑衍生物--3,6-二(1,2,4-三唑)-N-己基咔唑(4),其结构经1H NMR, IR和MS表征.利用UV,单光子荧光光谱和固体荧光光谱研究了4的线性光学性质,结果表明4有望成为具有应用价值的发光材料.     

3-亚甲基异苯并呋喃-1(3H)-酮及其衍生物的合成研究

以2-乙烯基苯甲酸甲酯及其衍生物为原料,经过酯水解反应,随后发生环氧化、环合反应制备了3-羟甲基异苯并呋喃-1(3H)-酮及其衍生物;再和三溴化磷或者对甲苯磺酰氯发生亲核取代,最后通过消除反应合成了3-亚甲基异苯并呋喃-1(3H)-酮及其衍生物.在亲核取代和消除反应中,对甲苯磺酰氯法比三溴化磷法产率高.目标产物及其中间体有10个是新化合物.化合物结构用1H NMR,13C NMR,MS和IR表征.目标产物在空气中长期放置没有发生二聚.     

手性双二茂铁基配体的合成、表征及固体CD光谱

以甲酰基二茂铁(1)和手性1,2-二苯基乙二胺[(1R, 2R)-1,2-二苯基乙二胺(2R), (1S,2S)-1,2-二苯基乙二胺(2S)]为原料, 经缩合、还原和N-烷基化反应, 制备了一对新型手性四齿双二茂铁基配体[N,N’-二(二茂铁基甲基)-N,N’-二(2-羟基丙基)-(1R,2R)-1,2-二苯基乙二胺(5R)和N,N’-二(二茂铁基甲基)-N,N’-二(2-羟基丙基)-(1S,2S)-1,2-二苯基乙二胺(5S)]. 用元素分析、红外(IR)、质子核磁共振(1H NMR)、紫外-可见(UV-Vis)、固体圆二色(CD)光谱等对手性产物(3R-5S)进行了表征. 固体CD光谱研究表明, 配体5R(或5S)的手性特征和4R(或4S)相似而与3R(或3S)却有一定差别.     

3-叠氮基-4-酰氯肟基呋咱的合成及其热稳定性

以3-氨基-4-酰氨肟基呋咱为原料,经重氮化和叠氮化反应合成了新化合物3-叠氮基-4-酰氯肟基呋咱(3),总收率67％.其结构经1H NMR,13C NMR,15N NMR,IR及元素分析表征.热失重法研究结果表明,3具有良好的热稳定性.     

Stereochemistry of chiral pentacoordinate spirophosphoranes correlated with solid-state circular dichroism and 1H NMR spectroscopy

Two sets of diastereomers of pentacoordinate spirophosphoranes separately derived from l-valine (or d-valine) and l-leucine (or d-leucine) were synthesized, isolated, and structurally characterized both in the solid state (X-ray crystallography and solid-state CD spectroscopy) and in the solution (¹H NMR). The Λ and Δ absolute configurations of a pair of enantiomers 3a and 4a with distorted trigonal bipyramids (TBPs) geometry are directly determined by X-ray diffraction analysis, respectively. The chiral-at-phosphorus features of the related diastereomers were correlated with their solid-state CD and ¹H NMR spectra.     

D3h-symmetrical hydrogen-bonding unit as a saccharide recognition and self-assembling module

A D(3h)-symmetrical triresorcinol module 1,3,5-tris(2,6-dihydroxy-4-pentylphenyl)benzene ( 3) was investigated in terms of its hydrogen-bonding ability for glycoside recognition and self-association. When 3 was treated with glycoside, corresponding changes were induced in (1)H NMR, UV, and CD spectra. The titration experiments indicated the participation of not only a 1:1 but also a 1:2 association of a glucosamine derivative guest. Self-association of 3 caused gelation with CDCl(3), and was studied by (1)H NMR and X-ray analysis.     

Synthesis and Crystal Structure of 3,3＇-Dimethyl-dibenzo-18-crown-6

1 INTRODUCTION Since the report about unusual coordination num- bers and arrangements to metal ions of crown ether compounds by Pedersen[1], the crown ether compounds have attracted much attention. Due to their novel coordination modes, crown ethers have been widely used in catalyst, solvent extraction, iso- tope separation, bionics, material chemistry, host- guest chemistry and supramolecular chemistry[2~5]. So it is vital to study the synthesis of new crown ethers and their crystal stru…     

Solid-state and high-resolution liquid 119Sn NMR spectroscopy of some monomeric, two-coordinate low-valent tin compounds: very large chemical shift anisotropies

High-resolution liquid- and solid-state 119Sn NMR spectroscopy was used to study the bonding environment in the series of monomeric, two-coordinate Sn(II) compounds of formula Sn(X)C6H3-2,6-Trip2 (X = Cl, Cr(eta 5-C5H5)(CO)3, t-Bu, Sn(Me)2C6H3-2,6-Trip2; Trip = C6H2-2,4,6-i-Pr3). The trends in the principal components of the chemical shift tensor extracted from the solid-state NMR data were consistent with the structures determined by X-ray crystallography. Furthermore, the spectra for the first three compounds displayed the largest 119Sn NMR chemical shift anisotropies (up to 3798 ppm) of any tin compound for which data are currently available. Relaxation time based calculations for the dimetallic compound 2,6-Trip2H3C6Sn-Sn(Me)2C6H3-2,6-Trip2 suggests that the chemical shift anisotropy for the two-coordinate tin center may be as much as ca. 7098 ppm, which is as broad as the 1 MHz bandwidth of the NMR spectrometer.     

Chiral 3D Coordination Polymers Consisting of Achiral Terpyridyl Precursors: from Spontaneous Resolution to Enantioenriched Induction

A pair of enantiomers of three-dimensional (3D) chiral coordination polymers (CCPs) were successfully constructed by using achiral components 4,2′:6′,4′′-terpyridyl precursors and Cu²⁺ through spontaneous resolution ( 1 a ). By utilising feeding controlled chiral-templated induction and chiral auxiliary behaviour of optically pure camphor sulfonate (CSA), the enantioenriched ( 1 b-P and 1 b-M ) and CSA captured ( 1 c-P and 1 c-M ) CCPs were successfully synthesised, respectively. The chiral information of the corresponding products was confirmed by X-ray single crystal diffraction and solid-state CD spectra. Meanwhile, the formation processes of 1 b-P and 1 b-M were monitored through solution CD spectra, UV/Vis spectra and ESI-TOF MS. Based on these results, a reasonable chiral-templated induction mechanism of forming 1 b-P and 1 b-M was proposed.     

Spectroscopic and Structural Study of the 1:2 Aluminium(III) Complex of Quercetin

Quercetin (3, 3’, 4’, 5, 7-pentahydroxyflavone) is one of the most common flavonols present in nature. The complexation of Al(III) by various flavonoids has been suggested to reduce the overload of aluminum in the diet, a metal which has been implicated…     

Natural-abundance solid-state 2H NMR spectroscopy at high magnetic field

High-resolution solid-state (2)H NMR spectroscopy provides a method for measuring (1)H NMR chemical shifts in solids and is advantageous over the direct measurement of high-resolution solid-state (1)H NMR spectra, as it requires only the application of routine magic angle sample spinning (MAS) and routine (1)H decoupling methods, in contrast to the requirement for complex pulse sequences for homonuclear (1)H decoupling and ultrafast MAS in the case of high-resolution solid-state (1)H NMR. However, a significant obstacle to the routine application of high-resolution solid-state (2)H NMR is the very low natural abundance of (2)H, with the consequent problem of inherently low sensitivity. Here, we explore the feasibility of measuring (2)H MAS NMR spectra of various solids with natural isotopic abundances at high magnetic field (850 MHz), focusing on samples of amino acids, peptides, collagen, and various organic solids. The results show that high-resolution solid-state (2)H NMR can be used successfully to measure isotropic (1)H chemical shifts in favorable cases, particularly for mobile functional groups, such as methyl and -N(+)H(3) groups, and in some cases phenyl groups. Furthermore, we demonstrate that routine (2)H MAS NMR measurements can be exploited for assessing the relative dynamics of different functional groups in a molecule and for assessing whole-molecule motions in the solid state. The magnitude and field-dependence of second-order shifts due to the (2)H quadrupole interaction are also investigated, on the basis of analysis of simulated and experimental (1)H and (2)H MAS NMR spectra of fully deuterated and selectively deuterated samples of the α polymorph of glycine at two different magnetic field strengths.