首页> 外文学位 >Organic Ligand Investigations to Assess the Potential for Palladium and Platinum Coordination
【24h】

Organic Ligand Investigations to Assess the Potential for Palladium and Platinum Coordination

机译:有机配体研究以评估钯和铂的配位潜力

获取原文
获取原文并翻译 | 示例

摘要

Palladium and platinum complexes are of great importance to chemists for their unique ability to assume a wide variety of chemical roles. They are of interest to synthetic chemists chiefly due to their well-known ability to catalyze coupling reactions, greatly increasing yield and efficiency. Since its introduction to the literature in 1974 by Bonnett and Ibers, tris(dibenzylideneacetone)-dipalladium(chloroform) (Pd2(dba)3˙CHCl3) has been reported hundreds of times as a source of zero-valent palladium and is widely used as a conveniently soluble homogeneous palladium catalyst.;A palladium complex reported by Itoh et al. spurred interest in pursuing ligand studies on compounds that have a benzoquinone motif for stabilizing zero-valent palladium and platinum compounds. Itoh's complex, Pd 2(bq)2(nbe)2, resulted in two palladium atoms each coordinated to a double bond of the benzoquinone (bq) and coordinated to a single norbornene (nbe) ligand. Itoh et al. also showed that a single palladium atom could be stabilized by using bq and cyclooctadiene (cod) ligands. This complex, Pd(bq)(cod) further showed that palladium was amenable to eta-bonding interactions with the double bonds of bq, and therefore ligand studies included organic compounds with the bq motif. Previous work by Nate Fisher and Dominick Babbini has included the synthesis and characterization of tripalladium sandwich complexes. This unique system contains three zero-valent palladium centers stabilized by eta-bonding between electron density in the double bonds of the tropylium ion and the palladium atoms.;An issue with zero-valent metal centers is that they bring with them an intrinsic instability, making preparation and shelf-life potential issues for complexes of this nature. Both palladium and platinum are able to form eta, eta, bonds with pi, pi,-conjugated systems like those in dibenzylideneacetone (dba) analogues and tropylium (C 7H7)+. With the massive amount of unsaturated pi-conjugated systems available to chemists, there are plenty of compounds that can potentially be used to stabilize zero-valent metal centers. It is an interest of chemists to develop organometallic compounds that stabilize zero-valent metal centers because these compounds are often readily soluble in organic solvents, but more importantly, the ligands can release the zero-valent metal which can participate in subsequent reactions, such as catalytic processes. The eta-bonding motif often associated with zero-valent palladium complexes is a weaker bond than a direct sigma-bond to a ligand.;With the previous success of the tripalladium [Pd3Tr 2X3]-- motif, it was desirable to synthesize a series of compounds that palladium could theoretically interact with through eta-type bonding. The inclusion of pi-bonds in various organic compounds should, in theory, be amenable to palladium coordination. By designing uncharged ligands, one can isolate zero-valent palladium compounds that could be used as Pd2(dba)3˙CHCl3 analogues. It is for this reason that a series of 7-aryl-6H-dibenzo[b,h]xanthene-5,6,8,13(7H)-tetraone (BNQ), 14-phenyl-14H-dibenzo[a,j]xanthene (DBX), 3,4,5,6,7,9-Hexahydro-3,3,6,6- tetramethyl-9-phenyl-1H-xanthene-1,8(2H)-dione (TMXD), and 4'-Aryl-2,2':6',2''-terpyridines (terpy) compounds were synthesized and characterized.
机译:钯和铂配合物对化学家非常重要,因为它们具有承担多种化学作用的独特能力。它们是合成化学家所感兴趣的,主要是因为它们众所周知的催化偶联反应的能力,大大提高了产率和效率。自1974年Bonnett和Ibers将其引入文献以来,三(二亚苄基丙酮)-二钯(氯仿)(Pd2(dba)3·CHCl3)已被报道数百次作为零价钯的来源,并被广泛用作一种方便溶解的均相钯催化剂。Itoh等报道的钯配合物。在对具有苯醌基序的化合物进行配体研究以稳定零价钯和铂化合物方面引起了人们的兴趣。伊藤的络合物Pd 2(bq)2(nbe)2产生两个钯原子,每个钯原子与苯醌(bq)的双键配位并与单个降冰片烯(nbe)配体配位。伊藤等。还表明,使用bq和环辛二烯(cod)配体可以稳定单个钯原子。这种复合物Pd(bq)(cod)进一步表明,钯适合与bq的双键进行eta键相互作用,因此配体研究包括具有bq图案的有机化合物。 Nate Fisher和Dominick Babbini的先前工作包括三方三明治复合物的合成和表征。这个独特的系统包含三个零价钯中心,这些中心通过对位鎓离子和钯原子的双键中的电子密度之间的η键稳定化。;零价金属中心的一个问题是它们带来固有的不稳定性,为这种性质的配合物准备和潜在的保质期问题。钯和铂均能够与pi,pi共轭体系形成eta,eta键,例如二亚苄基丙酮(dba)类似物和对(C 7H7)+。随着化学家可获得大量的不饱和pi共轭体系,有许多化合物可以潜在地用于稳定零价金属中心。化学家的兴趣是开发能够稳定零价金属中心的有机金属化合物,因为这些化合物通常易于溶于有机溶剂,但是更重要的是,配体可以释放零价金属,从而可以参与后续反应,例如催化过程。与零价钯配合物相比,常与零价钯配合物相关的η-键基序键较弱。与三方钯[Pd3Tr 2X3]-基序的先前成功相结合,人们希望合成一系列理论上讲,钯可以通过eta型键与之相互作用的化合物。理论上,在各种有机化合物中包含pi键应该适合钯的配位。通过设计不带电荷的配体,可以分离可用作Pd 2(dba)3 -CHCl 3类似物的零价钯化合物。因此,一系列的7-芳基-6H-二苯并[b,h] h吨-5,6,8,13(7H)-四酮(BNQ),14-苯基-14H-二苯并[a,j] ] x吨(DBX),3,4,5,6,7,9-六氢-3,3,6,6-四甲基-9-苯基-1H-x吨-1,8(2H)-二酮(TMXD),合成并表征了4'-Aryl-2,2':6',2''-叔吡啶(terpy)化合物。

著录项

  • 作者

    Herring, Julian.;

  • 作者单位

    Northern Arizona University.;

  • 授予单位 Northern Arizona University.;
  • 学科 Inorganic chemistry.;Organic chemistry.;Chemistry.
  • 学位 M.S.
  • 年度 2018
  • 页码 139 p.
  • 总页数 139
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 新闻学、新闻事业;
  • 关键词

  • 入库时间 2022-08-17 11:41:17

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