• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Spin States of Homochiral and Heterochiral Isomers of [Fe(PyBo_x)_2]~(2+) Derivatives
【24h】

Spin States of Homochiral and Heterochiral Isomers of [Fe(PyBo_x)_2]~(2+) Derivatives

机译：[Fe（Pybo_x）_2]〜（2+）衍生物的旋转状态

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 following iron(II) complexes of 2,6-bis(oxazolinyl) pyridine (PyBo_x; LH) derivatives are reported: [Fe(LH)_2] [ClO_4]_2 (1); [Fe((R)-L~(Me))_2][ClO_4]_2 ((R)-2; L~(Me)=2,6-bis{4-methyloxazolinyl} pyridine); [Fe((R)-L~(Ph))_2][ClO_4]_2 ((R)-3) and [Fe((R)-L~(Ph))((S)-L~(Ph))][ClO_4]_2 ((RS)-3; L~(Ph)=2,6-bis{4-phenyloxazolinyl}pyridine); and [Fe((R)-L~(iPr))_2][ClO_4]_2 ((R)-4) and [Fe((R)-L~(iPr))((S)-L~(iPr))] [ClO_4]_2 ((RS)-4; L~(iPr)=2,6-bis{4-isopropyloxazolinyl}pyridine). Solid (R)-3·MeNO_2 exhibits an unusual very gradual, but discontinuous thermal spin-crossover with an approximate T1=2 of 350 K. The discontinuity around 240 K lies well below T1=2, and is unconnected to a crystallographic phase change occurring at 170 K. Rather, it can be correlated with a gradual ordering of the ligand conformation as the temperature is raised. The other solid compounds either exhibit spin-crossover above room temperature (1 and (RS)-3), or remain high-spin between 5-300 K [(R)-2, (R)-4 and (RS)-4]. Homochiral (R)-3 and (R)-4 exhibit more twisted ligand conformations and coordination geometries than their heterochiral isomers, which can be attributed to steric clashes between ligand substituents [(R)-3]; or, between the isopropyl substituents of one ligand and the backbone of the other ((R)-4). In solution, (RS)-3 retains its structural integrity but (RS)-4 undergoes significant racemization through ligand redistribution by ~1H NMR. (R)-4 and (RS)-4 remain high-spin in solution, whereas the other compounds all undergo spin-crossover equilibria. Importantly, T1=2 for (R)-3 (244 K) is 34 K lower than for (RS)-3 (278 K) in CD3CN, which is the first demonstration of chiral discrimination between metal ion spin states in a molecular complex.
机译：报道了2,6-双（恶唑啉基）吡啶（PybO_x; LH）衍生物的以下铁（II）复合物：[Fe（LH）_2] [CLO_4] _2（1）; [Fe（（r）-1〜（me））_ 2] [clo_4] _2（（r）-2; l〜（me）= 2,6-双{4-甲基恶唑啉基}吡啶）; [Fe（（R）-L〜（pH））_ 2] [CLO_4] _2（（R）-3）和[Fe（（（（（r）-L〜（pH））（（s）-L〜（pH） ）] [ClO_4] _2（（RS）-3; L〜（pH）= 2,6-双{4-苯基恶唑啉基吡啶）; [Fe（（r）-l〜（ipr））_ 2] _2] _2（（r）-4）和[fe（（r）-l〜（ipr））（（s）-l〜（ipr ））]] [ClO_4] _2（（RS）-4; L〜（IPR）= 2,6-双{4-异丙恶唑苯基}吡啶）。固体（R）-3·meno_2表现出不寻常的非常渐进的，但不连续的热旋转 - 交叉，其近似T1 = 2 of 350 K. 240 k约为240 k的不连续性远低于T1 = 2，并且与晶体相变不连接在170k处发生。相反，随着温度升高，它可以与配体构象的逐渐排序相关。另一种固体化合物在室温（1和（Rs）-3）上方表现出旋转交叉，或者保持高旋转在5-300k [（R）-2，（R）-4和（RS）-4之间]。 HOOCHIRAL（R）-3和（R）-4表现出比其异细类异构体具有更多扭曲的配体构象和配位几何形状，其可归因于配体取代基之间的空间裂纹[（r）-3];或者，在一个配体的异丙基取代基和另一个配体的骨架之间（（r）-4）之间。在溶液中，（RS）-3保持其结构完整性，但（RS）-4通过〜1H NMR通过配体再分配进行显着的外向性。 （r）-4和（Rs）-4保持高旋转溶液，而其他化合物全部经历旋转交叉平衡。重要的是，（R）-3（244k）的T1 = 2比CD3CN中的（RS）-3（278 k）低34 k，这是分子复合物中金属离子旋转状态之间的手性判别的第一次说明。

著录项

  • 来源
    《Chemistry: A European journal》 |2017年第38期|共9页
  • 作者

    Kay E. Burrows; Sarah E. McGrath; Rafal Kulmaczewski; Oscar Cespedes; Simon A. Barrett; Malcolm A. Halcrow;

  • 作者单位

    School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT (UK) Fax: (+44) 113-343-6565;

    School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT (UK) Fax: (+44) 113-343-6565;

    School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT (UK) Fax: (+44) 113-343-6565;

    School of Physics and Astronomy University of Leeds E. C. Stoner Building Leeds LS2 9JT (UK);

    School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT (UK) Fax: (+44) 113-343-6565;

    School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT (UK) Fax: (+44) 113-343-6565;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 应用化学;
  • 关键词

    chirality; iron; isomers; N-ligands; spin-crossover;

    机译：手性;铁;异构体;n-配体;旋转交叉;

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