二丁基锡氮杂环羧酸酯的合成

合成了１０种二丁基锡氮杂环羧酸酯（ｎ－Ｃ４Ｈ９）２Ｓｎ（Ｃｌ）２－ｎ（Ｏ２ＣＲ）ｎ（ｎ＝１,２;Ｒ＝吡啶基,吲哚烷基）,利用元素分析,ＩＲ及＾Ｈ ＮＭＲ表征了它们的结构。     

聚芳醚酮大环化合物的核磁共振谱解析

利用一维ＮＭＲ方法研究了新型聚芳醚酮大环化合物的影响，用二维同核＾１Ｈ－＾１Ｈ ＣＯＳＹ和＾１３Ｃ－＾１Ｈ ＣＯＳＹ实验方法以及类似物质标准谱图的比较，对一维ＮＭＲ谱峰进行了归属。     

NMR方法表征联萘衍生物：Ⅰ.2,2‘—二（对氨基氧基）—1,1’—联萘

用＾１Ｈ－ＮＭＲ＾１３Ｃ－ＮＭＲ和二维核共振技术研究了２，２’－二（对氨苯氧基）－１，１’－联萘的结构，并通过＾１Ｈ－＾１Ｈ质子同核相关及＾１３Ｃ－＾１Ｈ异核相关谱提供的信息确定了其＾１Ｈ谱和＾１３Ｃ谱中各谱峰的归属，为聚合物的表征提供依据。     

联萘衍生物的NMR表征

用一维＾１Ｈ ＮＭＲ、＾１３Ｃ ＮＭＲ方法研究了２,２’－（３,４－四酸二酐）二苯甲酰氧基－１,１‘－联萘的并通过二维＾１Ｈ－＾１Ｈ同核相关,＾１３Ｃ－＾１Ｈ异核相关及＾１３Ｃ－＾１Ｈ异核远程相关谱进一步地确定其＾１Ｈ谱和＾１３Ｃ谱中各谱峰的归属。为同类化合物的表征提供了依据。     

六氟磷酸二（4,4‘—二甲基—2,2’—联吡啶）.（2,2‘—联吡啶—4,4’—二羧？…

用＾１Ｈ ＮＭＲ和＾１３Ｃ ＮＭＲ谱研究了新型电化学发光探针六氟磷酸二（４,４’;－二甲基－２,２‘－联吡啶）．（４．４’－二羧酸－２,２‘－联吡啶）合钌的立体结构,通过＾１Ｈ ＾１Ｈ ＣＯＳＹ,＾１３Ｃ－＾１Ｈ ＨＥＴＣＯＲ谱对其氢谱和碳谱中的各谱峰进行了归属,并给出了氢谱和碳谱峰的化学位移值。     

对甲氧在偶氮苯衍生物的核磁共振表征

用一维＾Ｈ ＮＭＲ、＾１３Ｃ ＮＭＲ方法研究了对甲氧基偶氮苯衍生物的结构,并通过二维＾１Ｈ－＾１Ｈ同核相关谱（ＣＯＳＹ）、＾１３Ｃ－＾１Ｈ异核相关谱（ＨＥＴＣＯＲ）及＾１３Ｃ－＾１Ｈ异核远程相关谱进一步地确定了该类衍生物的＾１Ｈ和＾１３Ｃ谱中各谱峰的归属,为研究侧链液晶聚合物结构提供了有价值的数据。     

含硅香原料研究(VI)－顺(反)-1-取代-3-三甲硅基环己醇的合成、13C NMR谱及其香气评定

合成并分离得到７对１－取代－３－三甲硅基环己醇的顺、反异构体,它们的结构通过＾Ｈ ＮＭＲ、＾１３Ｃ ＮＭＲ、ＭＳ谱及ＧＣ（测其纯度）测定,利用＾１３Ｃ ＮＭＲ确定了各对顺、反异构体的构型。评定了各化合物的香气,大部化合的具有甜香或甜香与木香香气,其中（反）－１－正丁基－３－三甲硅基环己醇具有甜香和木香香气,香气透发,留香持久,质量上乘。     

研究塑性有机固体的1H NMR方法

塑性有机固体的＾１Ｈ ＭＡＳ ＮＭＲ谱通常由一高分辨谱与一宽线谱组成，其中高分辨谱分量对应于塑性相，而宽线谱分量对应于刚性相。长延迟回波－ＭＡＳ ＮＭＲ实验可测得塑性相的高分辨谱，ＣＲＡＭＰＳ方法可测得整个固体＾１Ｈ体系的高分辨谱，常温下它往往以刚性相的贡献为主要成分。实验结果表明，结合＾１Ｈ ＭＡＳ、回波－ＭＡＳ与ＣＲＡＭＰＳ等三种固态高分辨＾１Ｈ ＮＭＲ技术可望成为深入研究塑性有机固体中塑性相     

蛇鞭的化学成分研究：Ⅰ.蛇鞭中新化合物异亮氨酸—苏氨酸—2—甲基—…

从黑眉锦蛇的蛇鞭中分离得到一个淡黄色固体化合物，用ＩＲ，＾１Ｈ－ＮＭＲ，＾１３Ｃ－ＮＭＲ，ＭＳ等现代波谱方法鉴定其化学结构为异亮氨酸－苏氨酸－２－甲基－环己胺。该化合物是一个未见文献报道的新合物。     

苯乙烯—甲基丙烯酸甲酯嵌段共聚物的合成与表征

采用阴离子聚合技术合成了一系列苯乙烯－甲基丙烯酸甲酯的两嵌段共聚物。采用ＧＰＣ、ＦＴＩＲ、ＮＭＲ（＾１Ｈ ＮＭＲ，＾１３Ｃ ＮＭＲ和固体ＮＭＲ）和ＤＭＡ等手段进行了表征。结果表明，所得产物为高分子量，窄分布，具有微相分离结构的两嵌段共聚物。     

Infrared and Nuclear Magnetic Resonance Absorptions of Common Liquid Stationary Phases for Preparative Gas Chromatography

It is well known that many liquid stationary phases for gas chromatography have a tendency to bleed at high temperature and/or at high flow rate. This problem is especially important in preprative applications, since the liquid phase may then be the contaminant of a pure component. Such contaminant can hardly be deteced by gas chromatography. However, for routine spectral analysis it may introduce certain extraneous peaks in both infrared and nuclear magnetic resonance spectra of the pure component. Consequently, it is desirable to have handy references to avoid misleading by those peaks.     

Chemical Reaction Monitoring using Zero-Field Nuclear Magnetic Resonance Enables Study of Heterogeneous Samples in Metal Containers

We demonstrate that heterogeneous/biphasic chemical reactions can be monitored with high spectroscopic resolution using zero-field nuclear magnetic resonance spectroscopy. This is possible because magnetic susceptibility broadening is negligible at ultralow magnetic fields. We show the two-step hydrogenation of dimethyl acetylenedicarboxylate with para-enriched hydrogen gas in conventional glass NMR tubes, as well as in a titanium tube. The low frequency zero-field NMR signals ensure that there is no significant signal attenuation arising from shielding by the electrically conductive sample container. This method paves the way for in situ monitoring of reactions in complex heterogeneous multiphase systems and in reactors made of conductive materials while maintaining resolution and chemical specificity.     

Background-Free Detection of Spin-Exchange Dynamics at Ultra-Low Magnetic Field

Ultra-low field nuclear magnetic resonance spectroscopy (NMR) and imaging (MRI) inherently suffer from a low signal-to-noise ratio due to the small thermal polarization of nuclear spins. Transfer of polarization from a pre-polarized spin system to a thermally polarized spin system via the Spin Polarization Induced Nuclear Overhauser Effect (SPINOE) could potentially be used to overcome this limitation. SPINOE is particularly advantageous at ultra-low magnetic field, where the transferred polarization can be several orders of magnitude higher than thermal polarization. Here we demonstrate direct detection of polarization transfer from highly polarized ¹²⁹Xe gas spins to ¹H spins in solution via SPINOE. At ultra-low field, where thermal nuclear spin polarization is close to background noise levels and where different nuclei can be simultaneously detected in a single spectrum, the dynamics of the polarization transfer can be observed in real time. We show that by simply bubbling hyperpolarized ¹²⁹Xe into solution, we can enhance ¹H polarization levels by a factor of up to 151-fold. While our protocol leads to lower enhancements than those previously reported under extreme Xe gas pressures, the methodology is easily repeatable and allows for on-demand enhanced spectroscopy. SPINOE at ultra-low magnetic field could also be employed to study ¹²⁹Xe interactions in solutions.     

Chemical Reaction Monitoring using Zero‐Field Nuclear Magnetic Resonance Enables Study of Heterogeneous Samples in Metal Containers

We demonstrate that heterogeneous/biphasic chemical reactions can be monitored with high spectroscopic resolution using zero‐field nuclear magnetic resonance spectroscopy. This is possible because magnetic susceptibility broadening is negligible at ultralow magnetic fields. We show the two‐step hydrogenation of dimethyl acetylenedicarboxylate with para‐enriched hydrogen gas in conventional glass NMR tubes, as well as in a titanium tube. The low frequency zero‐field NMR signals ensure that there is no significant signal attenuation arising from shielding by the electrically conductive sample container. This method paves the way for in situ monitoring of reactions in complex heterogeneous multiphase systems and in reactors made of conductive materials while maintaining resolution and chemical specificity.     

Solvent suppression in solid-state DNP NMR using Electronic Mixing-Mediated Annihilation (EMMA)

We show here that the Electronic Mixing-Mediated Annihilation (EMMA) method, previously reported for the suppression of background signals in solid-state nuclear magnetic resonance spectra, can be successfully applied to remove the solvent signals observed in the case of nuclear magnetic resonance spectra obtained with dynamic nuclear polarization. The methodology presented here is applied to two standard sample preparation methods for dynamic nuclear polarization, namely, glass forming and incipient wetness impregnation. It is demonstrated that the Electronic Mixing-Mediated Annihilation method is complementary to the different methods for solvent suppression based on relaxation filters and that it can be used to preserve the quantitative information that might be present in the pristine spectra.     

1-甲基-3,4-二苯基喹啉-2(1H)-酮的合成和结构表征

以N-甲基苯胺和苯丙炔酸为原料,经过缩合、亲电环化、偶联反应合成了1-甲基-3,4-二苯基喹啉-2(1H)-酮;利用核磁共振谱和气相色谱-质谱表征了产物的结构.结果表明,所用合成方法具有产率高、反应条件温和、操作简单等优点,目标产物的总产率达62.7%.     

Obtaining the key set of typical vectors by factor analysis and subsequent isolation of component spectra

The key set of typical rows (or typical columns), used to reproduce a data matrix, are obtained by finding the set of rows (or set of columns) most orthogonal to each other. If the data matrix consists of the spectra of a series of related mixtures, and there exists at least one data point unique to each of the components, the spectra of the pure components can be isolated. The method is applied to problems in nuclear magnetic resonance, gas—liquid chromatography and mass spectrometry.     

Solid-State NMR Spectroscopy: A Powerful Technique to Directly Study Small Gas Molecules Adsorbed in Metal–Organic Frameworks

Metal–organic frameworks (MOFs) have shown great potential in gas separation and storage, and the design of MOFs for these purposes is an on-going field of research. Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a valuable technique for characterizing these functional materials. It can provide a wide range of structural and motional insights that are complementary to and/or difficult to access with alternative methods. In this Concept article, the recent advances made in SSNMR investigations of small gas molecules (i.e., carbon dioxide, carbon monoxide, hydrogen gas and light hydrocarbons) adsorbed in MOFs are discussed. These studies demonstrate the breadth of information that can be obtained by SSNMR spectroscopy, such as the number and location of guest adsorption sites, host–guest binding strengths and guest mobility. The knowledge acquired from these experiments yields a powerful tool for progress in MOF development.     

Analysis of Cyclocitral Mixtures by Nuclear Magnetic Resonance Spectroscopy

Abstract

Adequately separated signals in the nuclear megnetic resonance spectra of mixtures of cyclocitrals were assigned to the individual components. This assignment allowed direct integration of the signals of interst and calculation of the percentages of α-cyclocitral, β-cyclocitral, para-cymene, and 1-acetyl-4, 4-dimethyl-1-cyclohexene. The rapidity and nondestructive nature of the nuclear magnetic resonance analysis are superior to the fractional crystallization of the semi-carbazones and gas chromatography techniques previously utilized.     

A Convenient Method to Synthesize 1,3‐Selenazolidin‐2‐ones from 2‐Chloroethyl Amine Salts by Se/CO System under Atmospheric Pressure and Temperature

1,3‐Selenazolidin‐2‐ones were successfully synthesized by the reaction of 2‐chloroethyl amine salts with the Se/CO system via selenation and carbonylation in the presence of NaOH under atmospheric pressure and temperature, and were characterized by gas chromatography–mass spectrometry and nuclear magnetic resonance.