共查询到19条相似文献,搜索用时 78 毫秒
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采用电喷雾离子阱质谱法(ESI-MS)对10种环钯化二茂铁亚胺-膦配合物的质谱特征进行了研究, 获得了其结构碎片信息, 对其质谱裂解途径进行了解析. 结果表明, 在正离子检测方式下可以得到强的准分子离子峰[M-Cl]+簇, 它们的(+) ESI-MSn(n=1~3)质谱主要产生碳-膦键断裂的碎片, 同时也能观察到Pd—P或Pd—C键的断裂, 这些特征为此类化合物及其结构类似物的结构推断提供了依据. 相似文献
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选用新型双二茂铁亚胺环钯配合物(Fc2C NPh)Pd Cl PPh3(Fc=Ferrocenyl,Ph=Phenyl)作为催化剂,通过碘代二茂铁作为反应底物,进行Suzuki-Miyaura交叉偶联反应,以良好产率,合成了一系列具有特殊取代基的二茂铁衍生物(1~9).优化了制备二茂铁衍生物的交叉偶联反应条件,考察了底物适应范围,给出了优化合成路线,推测了催化反应机理.结果表明,选用的环钯配合物催化剂对潮气和空气不敏感,具有催化剂用量少(痕量)、催化反应活性高、底物适应范围宽等优点,是制备二茂铁衍生物的理想催化剂. 相似文献
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以1,1'-双(二苯基膦)二茂铁(dppf)、1,1'-双(二叔丁基膦)二茂铁(dtbpf)为配体,合成了一类双齿有机膦二茂铁钯(Ⅱ)配合物[(dppf)PdCl_2]、[(dtbpf)PdCl_2]、[(dppf)PdBr_2]和[(dtbpf)PdBr_2],通过核磁共振对配合物进行化学结构表征。评价了它们对Suzuki偶联反应、Sonogashira偶联反应、Heck偶联反应以及2-羟基吡啶与硼酸试剂之间的偶联反应的催化作用。结果表明,配合物化学性质稳定,在非保护气氛下能高效地催化一系列偶联反应。催化剂在单边Sonogashira偶联反应中不但具有较高的催化活性,而且有很好的选择性,显示出很好的应用前景。 相似文献
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高效液相色谱-电喷雾质谱(HPLC-ESI-MS/MS)测定新型抗癌铂配合物 总被引:2,自引:0,他引:2
采用高效液相色谱-电喷雾-多级质谱法(HPLC-ESI-MS/MS), 研究了cis-3,5-diisopropylsalylic cyclohexanodiaminoplatinum(Ⅱ)的电喷雾质谱行为, 鉴定了其杂质, 并测定了其纯度. 相似文献
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利用电喷雾质谱技术研究了四种N-杂环钯卡宾配合物,优化出较适宜检测的电喷雾质谱条件极性较高的溶剂(如乙腈),较低的离子源温度,样品浓度以1.0×10-4mol/L左右为宜,使用较低锥孔电压(5~35V).在此实验条件下,在全扫描电喷雾正离子谱中都会出现[M-I CH3CN] 及[M-I] 的质谱峰.通过源内碰撞诱导电离(CID)技术进一步分析样品在溶液中的性质.实验说明ESI不仅可作为一种分析工具,也可作为获得更多信息的一种方法,来研究有机金属基团在溶液中的性质. 相似文献
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环钯化二茂铁亚胺-三苯基膦配合物的合成、表征及催化Suzuki反应研究 总被引:6,自引:0,他引:6
为筛选高效催化Suzuki反应的催化剂, 合成了3种新的环钯化二茂铁亚胺-三苯基膦配合物2~4, 经元素分析(或HRMS)、 红外光谱和核磁共振谱对其结构进行了表征, 并通过X射线单晶衍射测定了化合物3的晶体结构. 这些化合物容易合成, 在空气和溶液中稳定, 可用作芳基溴及杂芳基溴与苯基硼酸偶联的Suzuki反应催化剂. 使用摩尔分数为0.01%的催化剂3, 以2倍量的K3PO4为碱, 于110 ℃下, 在甲苯中反应5~15 h, 使具有不同电子和位阻效应的取代芳基溴及杂芳基溴能以较高的产率与苯基硼酸反应生成偶联产物; 与溴苯相比, 带吸电子基的溴苯反应活性较高, 催化剂的摩尔分数降低至0.001%时, 仍能得到较高产率, 而带强给电子基的溴苯如4-溴苯甲醚及带邻位取代基的溴苯在其它条件相同时, 需要延长反应时间才能得到较高的产率. 相似文献
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胺烷基二茂铁衍生物研究(Ⅱ)——(N、N-二乙基)胺甲基二茂铁钯配合物与烯烃的反应 总被引:1,自引:0,他引:1
本文报道了(N,N-二乙基)胺甲基二茂铁钯配合物的合成及其与烯烃的反应,以及(N,N-二乙基)胺甲基二茂铁(Ⅰ)、钯配合物(Ⅱ)和反应产物的波谱性质。 1 实验 1.1 仪器 IR光谱用Shimadzu IR-450红外分光光度计测定,固体用KBr压片,液体用CsI涂片。Ⅰ和反应产物的~1H NMR谱用Varian EM-390核磁共振仪测定,氘代氯仿作溶剂;Ⅱ用Varian XL-200核磁共振仪测定;氘代二甲亚砜作溶剂。均以TMS作内标。 相似文献
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通过直接进样方式,采用电喷雾电离质谱技术分析了8个合成的富勒烯-N-甲基吡咯烷衍生物,详细研究了其在电喷雾条件下的质谱行为。由结果可知,该类化合物在电喷雾电离过程中易得到电子而负离子化;当衍生物结构中有相对易质子化基团或有活泼氢时,则可获得质子化和去质子的正负离子谱图;衍生物在负离子模式下容易失去吡咯环产生富勒烯负离子,且在合适能量碰撞下易发生衍生化基团内部的逆环加成反应,通过失去1个中性小分子物质CH2‖N—CH3,产生新的一取代亚甲基富勒烯衍生物。基于电喷雾电离源技术联合离子阱分析器建立的质谱分析方法,不但能提供准确的分子量信息,还能通过获得高分辨同位素谱峰和丰富的二级碎片离子峰,进一步确认化合物的分子结构,是一种先进、快速的富勒烯吡咯烷衍生物定性分析方法。 相似文献
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Wojciech Ostrowski Błażej Gierczyk Marcin Hoffmann Rafał Frański 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):1141-1150
Abstract The complexes of 2-phenyl-1,3,4-selena(thia/oxa)diazole with a palladium cation were studied by using electrospray ionization mass spectrometry. Palladium chloride was used as a source of palladium cations. The complexes of ligand:metal stoichiometry of 3:1 (ions [L3+PdCl]+) were formed for selenadiazoles and thiadiazoles. Quantum mechanical calculations performed indicated that ligand molecules are attached to palladium cation by the N-4 atom. The fragment ions formed [L2–H+Pd]+ may be regarded as organometallic species. Selenadiazoles were found more prone to form the palladium complexes than thiadiazoles. Oxadiazoles did not yield the respective palladium complexes. For comparison, the nickel cation was also included in the study but only 1:1, and less abundant 2:1 complexes were observed. Exchange of selenium into oxygen does not affect the abilities of the ligands to form nickel complexes. 相似文献
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Dr. Tyler K. Trefz Dr. Matthew A. Henderson Prof. Mikko Linnolahti Dr. Scott Collins Prof. J. Scott McIndoe 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(7):2980-2991
Electrospray‐ionization mass spectrometric studies of poly(methylaluminoxane) (MAO) in the presence of [Cp2ZrMe2], [Cp2ZrMe(Cl)], and [Cp2ZrCl2] in fluorobenzene (PhF) solution are reported. The results demonstrate that alkylation and ionization are separate events that occur at competitive rates in a polar solvent. Furthermore, there are significant differences in ion‐pair speciation that result from the use of metallocene dichloride complexes in comparison to alkylated precursors at otherwise identical Al/Zr ratios. Finally, the counter anions that form are dependent on the choice of precursor and Al/Zr ratio; halogenated aluminoxane anions [(MeAlO)x(Me3Al)y?z(Me2AlCl)zMe]? (z=1, 2, 3…?) are observed using metal chloride complexes and under some conditions may predominate over their non‐halogenated precursors [(MeAlO)x(Me3Al)yMe]?. Specifically, this halogenation process appears selective for the anions that form in comparison to the neutral components of MAO. Only at very high Al/Zr ratios is the same “native” anion distribution observed when using [Cp2ZrCl2] when compared with [Cp2ZrMe2]. Together, the results suggest that the need for a large excess of MAO when using metallocene dichloride complexes is a reflection of competitive alkylation vs. ionization, the persistence of unreactive, homodinuclear ion pairs in the case of [Cp2ZrCl2], as well as a change in ion pairing resulting from modification of the anions formed at lower Al/Zr ratios. Models for neutral precursors and anions are examined computationally. 相似文献
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应用电喷雾(ESI)质谱及其多级串联质谱(MS~n)技术研究了三个氨基酸衍 生物N-(N-亚甲基-2-吡咯烷酮)-缬氨酸(PMV),N,N-二-(N-亚甲基-2-吡咯烷 酮)-亮氨酸(PML)和N,N-二-(N-亚甲基-2-吡咯烷酮)-β-丙氨酸(PMA)在电 喷雾条件下的质谱行为。在此条件下三个氨基酸衍生物PMV,PML和PMA可以质子化 形式PMVH~+,PMLH~+和PMAH~+存在,并且检测到它们的Na~+和K~+的加合物。在电 喷雾条件下PMV,PML和PMA优先采取C-N键的断裂,并且通过分子间的氢键作用形成 了许多二聚和三聚物种。 相似文献
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邻二肟配合物和邻肟-亚胺配合物已作为维生素B_(12)的模拟物加以研究。二齿异亚硝基-β-酮胺配体,由于其异亚硝基(肟基)配位功能而引起人们的兴趣。在已知的这类配体的金属配合物中,肟 相似文献
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The crystal structure determination and mass spectrometric fragmentation analysis of the medicinal ingredient eprosartan (4-[2-butyl-5-(2-carboxy-3-thiophen-2-yl-propenyl)-imidazol-l-ylmethyl]-benzoic acid) are presented. The single-crystal X-ray diffraction shows that the colorless transparent crystal of eprosartan is of monoclinic system, space group P2/c with a = 16.1861(15), b = 10.9813(12), c = 28.610(3) A, β = 118.452(2)°, Z = 4, V= 4471.1(8) A3, Dc = 1.288 g/cm3,μ(MoKα) = 0.178 mm^-1 and F(000) = 1831. The independent part of the unit cell contains two eprosartan molecules and one unordered H2O molecule in the crystal structure which is fixed by inter- and intramolecular hydrogen bonds. The product ions in electrospray ionization tandem mass spectrometry (ESI-MSn) displays the protonated eprosartan dissociated in three competitive pathways and the fragmentation mechanism is proposed and supported by the FTICRMSn results. 相似文献
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The fragmentation of the antiviral drug adefovir dipivoxil and its two active metabolites, adefovir and monopivoxil adefovir, was investigated using both ion trap and triple-quadrupole mass spectrometers. Fragment ions due to loss of 30 Da were observed and attributed to an unanticipated rearrangement process by loss of formaldehyde. The proposed mechanism is supported with the aid of three newly synthesized adefovir derivatives and with accurate mass measurement. Other fragmentations by loss of a pivaloyl group, loss of water, C-P bond cleavage and C-O bond cleavage were also observed for adefovir derivatives. It was concluded that the compounds containing a >POO-CHR-OCO- group generally displayed a rearrangement reaction by loss of RCHO in collision-induced dissociation, and the process generally required an activation energy lower than for a direct bond cleavage. 相似文献
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Six palladium(Ⅱ) complexes with isonitrosoethylacetoacetate imine Schiff base ligands, Pd(R-IEAI)2, were prepared and characterized by IR, Raman and electronic spectra. Complex tran Pd(p-CH3C6H4-IEAI)2 (2) cry- stallizes in the monoclinic system, space group P21/c,with a=1.2002(2),b=0.9972(2),c=1.1121(2)nm,β=90.43(3)°,Z=2,F(000)=616,μ=7.44cm-1. The final R and wR are 0.0244 and 0.0625 for 2620 ob-served reflections with I≥2σ(I), respectively. The geometry around the Pd(Ⅱ) ions in those complexes has a distorted PdN4 square plane, the Schiff base ligands R-IEAI- being coordinated through their oximino-nitrogen atoms and imino-nitrogen atoms. 相似文献