• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Metal cation affinities of commonly used MALDI matrices determined by guided ion beam tandem mass spectrometry: Implications for MALDI mass analyses.
【24h】

Metal cation affinities of commonly used MALDI matrices determined by guided ion beam tandem mass spectrometry: Implications for MALDI mass analyses.

机译：通过导向离子束串联质谱法测定的常用MALDI基质的金属阳离子亲和力：对MALDI质量分析的意义。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The kinetic energy dependence of the collision-induced dissociation of M+(xBA) and M+(MALDI) complexes with Xe is studied using guided on beam tandem mass spectrometry. The xBA ligands studied include benzoic acid and all of the mono- and dihydroxy substituted benzoic acids: 2-, 3-, and 4-hydroxybenzoic add and 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-dihydroxybenzoic acid. The MALDI ligands studied include: quinoline, 3-aminoquinoline, 4-nitroaniline, nicotinic acid, picotinic acid, 3-hydroxypicolinic acid, ferrulic acid, sinapic acid, alpha-cyano-4-hydroxycinnamic add, and 4-hydroxyphenylazobenzoic acid. The metal cations examined include: Na+, K+, and Ag+. The dominant dissociation pathway for the Na+(xBA), K +(xBA), Na+(MALDI), and K+ (MALDI) complexes is simple collision-induced dissociation (CID) corresponding to endothermic loss of the intact xBA or MALDI ligand. Simple CID is generally also observed for the Ag+(xBA) and Ag+(MALDI) complexes. However, low-energy activated dissociation pathways are also observed in the CID of these latter complexes.; The cross section thresholds for loss of the intact xBA or MALDI ligand are interpreted to yield zero and 298 K M+-- xBA and M+--MALDI bond dissociation energies (BDEs) for the Na+(xBA), K+( xBA), Na+(MALDI) K+(MALDI) and several of the Ag+(x8A) and Ag+(MALDI) complexes, while upper bounds for these BDEs are provided in cases where low-energy activated dissociation pathways are observed.; Ab initio and density functional theoretical calculations are performed at the B3LYP/6-310* and B3LYP/6-31G*-SRSC levels of theory to obtain structures, molecular constants, and dipole moments for the neutral xBA and MALDI M+(xBA) and M+(MALDI) complexes, and transition states between different stable conformations of these species. Theoretical estimates for the BDEs of the M+( xBA) and M+(MALDI) complexes are determined from calculations at the B3LYP and MP2(full) levels of theory using 6-311+G(2d,2p) and 6-311+G(2d,2p)-SRSC basis sets and the 63LYP/6-31G* and B3LYP/6-31G*-SRSC optimized geometries. Zero point energy and basis set super position error corrections are also included in the calculated BDEs. Theoretical estimates for the isotropic molecular polarizabilities of the neutral xBA and MALDI ligands are determined at the PBE0/6-311+G(2d,2p) level of theory using the B3LYP/6-31G* optimized geometries. The stability of the neutral xBA and MALDI ligands and their metal cationized complexes are enhanced by intramolecular hydrogen bonds formation and chelation interactions. UV visible spectra of solutions of the xBA ligands and MALDI matrices are obtained to investigate the possible use of these ligands with various lasers. The experimentally determined BDEs are compared with those calculated here and reported in the literature.
机译：利用引导的串联质谱研究了M +（xBA）和M +（MALDI）配合物与Xe碰撞诱导解离的动能依赖性。研究的xBA配体包括苯甲酸以及所有的单羟基和二羟基取代的苯甲酸：2-，3-和4-羟基苯甲酸加成和2,3-，2,4-，2,5-，2,6- ，3,4-和3,5-二羟基苯甲酸。所研究的MALDI配体包括：喹啉，3-氨基喹啉，4-硝基苯胺，烟酸，吡啶甲酸，3-羟基吡啶甲酸，阿魏酸，芥子酸，α-氰基-4-羟基肉桂酸和4-羟基苯基偶氮苯甲酸。检查的金属阳离子包括：Na +，K +和Ag +。 Na +（xBA），K +（xBA），Na +（MALDI）和K +（MALDI）复合物的主要解离途径是简单的碰撞诱导解离（CID），对应于完整xBA或MALDI配体的吸热损失。通常还观察到Ag +（xBA）和Ag +（MALDI）配合物的简单CID。但是，在这些复合物的CID中也观察到了低能激活的解离途径。完整的xBA或MALDI配体损失的横截面阈值被解释为对Na +（xBA），K +（xBA），Na +（）产生零和298 K M +-xBA和M + -MALDI键解离能（BDE）。 MALDI）K +（MALDI）以及几种Ag +（x8A）和Ag +（MALDI）配合物，而在观察到低能活化解离途径的情况下，提供了这些BDE的上限。在理论水平的B3LYP / 6-310 *和B3LYP / 6-31G * -SRSC上进行从头算和密度泛函理论计算，以获得中性xBA和MALDI M +（xBA）的结构，分子常数和偶极矩。 M +（MALDI）配合物，以及这些物种不同稳定构象之间的过渡态。 M +（xBA）和M +（MALDI）配合物的BDE的理论估计值是根据B3LYP和MP2（full）理论水平的计算确定的，使用6-311 + G（2d，2p）和6-311 + G（ 2d，2p）-SRSC基础集以及63LYP / 6-31G *和B3LYP / 6-31G * -SRSC优化的几何形状。零点能量和基集超级位置误差校正也包括在计算的BDE中。使用B3LYP / 6-31G *优化的几何结构，在理论上的PBE0 / 6-311 + G（2d，2p）水平确定中性xBA和MALDI配体各向同性分子极化的理论估计。分子内氢键的形成和螯合相互作用增强了中性xBA和MALDI配体及其金属阳离子化配合物的稳定性。获得了xBA配体和MALDI基质溶液的紫外可见光谱，以研究这些配体在各种激光中的可能用途。将实验确定的BDE与此处计算的BDE进行比较，并在文献中进行报道。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号