• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Crystal growth & design >Structural Transference and Regulation of Bimodal Assembly of Charge-Assisted Hydrogen-Bonded Networks
【24h】

Structural Transference and Regulation of Bimodal Assembly of Charge-Assisted Hydrogen-Bonded Networks

机译：电荷辅助氢键网络的双峰组装的结构转移和调控

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 salt[2,2'-(1,4-phenylene)pyrimidine2+][hexacyanocyclopropanediide2-]([PBA2+][C6(CN)62-])(1)crystallized from organic solvents as two polymorphic forms through charge-assisted N-H…NC hydrogen bonding between the oppositely charged ions.The red polymorph(1R)crystallized in the Fdd2 space group,forming ribbons in which the pair of N-H groups on the same side of the PBA2+ion entered two modes of hydrogen bonding,one that can be described as a R_2~2(15)motif involving a pair of geminal cyano groups(i.e.,on the same methylidene carbon atom)of the C6(CN)_)6~(2-)ion and the other a R?2(18)motif involving a pair of nongeminal cyano groups(i.e.,on different methylidene carbon atoms).The green polymorph(1G)crystallized in the P1 space group and adopted a"staircase"ribbon motif with"risers"comprising two PBA2+ions that bridged C6(CN)_6~(2-)ions through N-H…NC hydrogen bonds.This form also exhibited two modes of hydrogen bonding,the R_2~2(15)motif and a more complex one involving multiple molecules.The different colors of the polymorphs were assignable to pi-pi charge-transfer interactions between the weak C6(CN)_6~(2-)electron donor and the weak PBA2+electron acceptor in the solid state,a feature suggested by single-crystal X-ray diffraction and confirmed by infrared spectroscopy.Heating 1G above 275 deg C produced a crystalline white polymorph(1W).The 1R form,however,exhibited thermal stability up to at least 300 deg C.The related salt[2,2'-(1,2-ethanediyl)pyrimidine2+]-[bexacyanocyclopropanediide2-]([EBA2+][C6(CN)_6~(2-)])(2Y)crystallized in the P2/c space group as yellow bipyramidal plates,forming infinite zigzag hydrogen-bonding ribbons.Unlike 1R and 1G,however,2Y only exhibits the R_2~2(18)motif because the shorter span of the EBA2+molecule,as defined by the intramolecular separation between N-H groups,did not allow formation of the R_2~2(15)motif.These structures reveal that the hydrogen-bonding modes of a bimodal system can be regulated through adjustment of key molecular structure parameters,which in the case of EBA2+produces a single hydrogen-bonding mode that is required for a hypothetical cyclic motif.Furthermore,the structural parameters of the ribbon motifs provide guidance for the choice of guest molecules capable of promoting formation of a cyclic motif through templating.
机译：盐[2,2'-（1,4-亚苯基）嘧啶2 +] [六氰基环丙烷二酰亚胺2-]（[PBA2 +] [C6（CN）62-]）（1）从有机溶剂中通过电荷辅助NH结晶为两种多晶型形式…带相反电荷的离子之间的NC氢键键合。红色多晶型物（1R）在Fdd2空间群中结晶，形成带，其中PBA2 +离子同一侧的一对NH基团进入两种氢键合模式，可以被描述为涉及C 6（CN）_）6〜（2-）离子的一对双氰基氰基（即，在相同的亚甲基碳原子上）的R_2〜2（15）基，另一个R 1为R 2。 2（18）基序，涉及一对非基氰基基团（即在不同的亚甲基碳原子上）。绿色多晶型物（1G）在P1空间群中结晶，并采用带有“上升”的“楼梯”色带基序，包含两个PBA2 +离子通过NH…NC氢键桥接C6（CN）_6〜（2-）离子。这种形式还表现出两种氢键合模式：R_2〜2（15）基序和一种更复杂的氢键涉及多个分子多晶型物的不同颜色可归因于固态的弱C6（CN）_6〜（2-）电子供体与弱PBA2 +电子受体之间的pi-pi电荷转移相互作用，这是单个提示的特征。结晶X射线衍射并通过红外光谱法确认。在275℃以上加热1G，产生结晶的白色多晶型物（1W）。然而1R形式在至少300℃下表现出热稳定性。相关盐[2，在P2 / c空间群中结晶的2'-（1,2-乙二基）嘧啶2 +]-[贝沙酰氨基环丙烷二胺2-]（[EBA2 +] [C6（CN）_6〜（2-）]）（2Y）呈黄色双锥体板结晶，形成无限的之字形氢键键合带。但是，与1R和1G不同，2Y仅显示R_2〜2（18）模体，因为EBA2 +分子的跨度较短，这是由NH基团之间的分子内分离确定的，不允许形成这些结构揭示了双峰体系的氢键模式可以通过调节键摩尔来调节分子结构参数，在EBA2 +的情况下，会产生假设的环状基序所需的单个氢键模式。此外，带状基序的结构参数为选择能够促进分子形成的客体分子提供了指导。通过模板形成环状图案。

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