α,α',α''-Nitrilo(6-methyl-2-pyridinecarboxylic acid) | 345349-98-6

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡啶及其衍生物
• 英文名称: α,α',α''-Nitrilo(6-methyl-2-pyridinecarboxylic acid)
• 英文别名: α,α',α''-nitrilotris(6-methyl-2-pyridinecarboxylic acid)；α,α',α''-nitrilotri(6-methyl-2-pyridinecarboxylic acid)；6-[[Bis[(6-carboxypyridin-2-yl)methyl]amino]methyl]pyridine-2-carboxylic acid
• CAS: 345349-98-6
• 化学式: C₂₁H₁₈N₄O₆
• 分子量: 422.397
• InChiKey: RGWCMZMRKPTMHW-UHFFFAOYSA-N

物化性质

• 沸点：
  699.7±55.0 °C(Predicted)
• 密度：
  1.483±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  -1.1
• 重原子数：
  31
• 可旋转键数：
  9
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.14
• 拓扑面积：
  154
• 氢给体数：
  3
• 氢受体数：
  10

反应信息

• 作为反应物：
  描述：

  terbium(III) chloride hexahydrate 、 α,α',α''-Nitrilo(6-methyl-2-pyridinecarboxylic acid) 以 水 为溶剂， 生成 [Tb(α,α',α''-nitrilotri(6-methyl-2-pyridinecarboxylate)(H2O)]2*7H2O
  参考文献：
  名称：

  新型七齿三脚架配体镧系元素配合物的固态和溶液性质：to弛豫效率得到提高的to配合物的途径。

  摘要：

  三脚架配体（alpha，alpha'，alpha''tritrilotri（6-methyl-2-pyridine羧酸））（H（3）tpaa）形成具有松弛度（r（1p）= 13.3 mM （-1）在25摄氏度和60 MHz时的s（-1）明显高于当前临床上使用的基于八配位聚氨基羧酸盐复合物的造影剂（3.5-4.7 mM（-1）s（-1））和合理的热力学稳定性。配体及其La，Nd，Eu，Gd，Tb，Ho，Tm，Yb和Lu络合物的晶体结构已通过X射线晶体学测定。中性H（3）tpaa分子在固态下采用预先组织的三脚架构型，其中三个H（3）tpaa臂位于分子的同一侧，准备以七齿配位方式结合金属离子。Ln（III）配合物的结构沿着其核数和与金属配位的水分子数沿系列变化，并且观察到La（3+）离子的四聚体结构（9和10配位的金属中心） ，由Nd（3+）离子通过Yb（3+）离子（9坐标）形成二聚结构，而Lu

  DOI：

  10.1021/ic010591+
• 作为产物：
  描述：

  tris[6-((2-N,N-diethylcarbamoyl)pyridyl)methyl]amine 在 sodium hydroxide 作用下， 以 乙醇 为溶剂， 生成 α,α',α''-Nitrilo(6-methyl-2-pyridinecarboxylic acid)
  参考文献：
  名称：

  A new heptadentate tripodal ligand leading to a gadolinium complex with an improved relaxation efficiency

  摘要：

  The new heptadentate tripodal ligand tpaa containing three pyridinecarboxylate binding units reacts with Gd(III) in water to give a thermodynamically stable complex which displays high relaxivity.

  DOI：

  10.1039/b100657f

文献信息

• Relating Structural and Thermodynamic Effects of the Pb(II) Lone Pair:  A New Picolinate Ligand Designed to Accommodate the Pb(II) Lone Pair Leads to High Stability and Selectivity
  作者：Aymeric Pellissier、Yann Bretonnière、Nicholas Chatterton、Jacques Pécaut、Pascale Delangle、Marinella Mazzanti

  DOI：10.1021/ic061823d

  日期：2007.4.30

  The crystal and molecular structure and the stability of lead and calcium complexes of two chelates containing picolinate chelating groups in different geometries have been investigated in order to relate the ligand affinity and selectivity for lead over calcium with the ability of the ligand to accommodate a stereochemically active lone pair. The crystal structures of the lead complexes of the diprotonated and monoprotonated tripodal ligand tpaa(2-) show that the three picolinate arms of the tripodal ligand coordinate the lead in an asymmetric way leaving a gap in the coordination sphere to accommodate the lead lone pair. As a consequence of this binding mode, one picolinate arm is very weakly bound and therefore can be expected to contribute very little to the complex stability. Conversely, the geometry of the dipodal ligand H(2)dpaea is designed to accommodate the lead lone pair; in the structure of the [Pb(dpaea)] complex the donor atoms of the ligand occupy only a quarter of the coordination sphere, reducing the sterical interaction between the lead lone pair with respect to the H(3)tpaa complexes. As a result, in the lead structures of H(2)dpaea all the ligand donor atoms are strongly bound to the metal ion leading to increased stability. The high value of the formation constant measured for the lead complex of the dipodal dpaea(2-) (log beta(11)(Pb) = 12.1(3)) compared to the lower value found for the one of the tripodal tpaa(3-) (log beta(11)(Pb) = 10.0(1)) provides direct evidence of the influence of the stereochemically active lead lone pair on complex stability. As a result, since the ligand geometry has little effect on the stability of the calcium complex, a remarkable increase in the Pb/Ca selectivity is observed for dpaea(-)(10(6.6)) compared to tpaa(3-) (10(1.5)), making the dipodal ligand a good candidate for application as extracting agent for the lead removal from contaminated water.