Monopicolinate-dipicolyl Derivative of Triazacyclononane for Stable Complexation of Cu<sup>2+</sup> and <sup>64</sup>Cu<sup>2+</sup>
作者:Melissa Roger、Luís M. P. Lima、Mathieu Frindel、Carlos Platas-Iglesias、Jean-François Gestin、Rita Delgado、Véronique Patinec、Raphaël Tripier
DOI:10.1021/ic400174r
日期:2013.5.6
The synthesis and characterization of Hno1pa2py, a new tacn-based ligand, is reported. The complexation process with Cu2+ was proved to be very fast even in acidic medium. Potentiometric titrations allowed us to establish that Hno1pa2py exhibits an overall low basicity as well as a high selectivity for Cu2+ over Zn2+ cations. The copper(II) complex was synthesized and characterized using UV–vis and
Significant relaxivity gap between a low-spin and a high-spin iron(<scp>ii</scp>) complex of structural similarity: an attractive off–on system for the potential design of responsive MRI probes
similar iron complexes in the oxidation state II that exist in a low-spin and a high-spin electronic spin state in aqueous media, respectively. The low-spin, diamagnetic complex (LS, 1) is mute in MRI while the high-spin, paramagnetic complex (HS, 2) generates considerable contrast in MRI. These results demonstrate that iron(II) complexes, hitherto neglected for contrast enhancement in MRI, have potential
我们已经确定了一对在氧化态II中结构相似的铁配合物,它们分别在水性介质中以低自旋和高自旋电子自旋态存在。低自旋抗磁性复合物(最小二乘,1)在MRI中是静音的,而高旋转顺磁性复合物(HS,2)在MRI中产生相当大的对比度。这些结果表明,迄今为止被忽略以增强MRI对比度的铁(II)配合物具有设计MRI探针的潜力,该MRI探针在目标生化活性的影响下会从一种状态传递到另一种状态,因此处于关闭状态–on模式。在300 MHz(质子 7 T场强时的共振频率)和 磷酸盐缓冲液,我们发现纵向弛豫率(r 1)为1.29 mM -1 s -1对于2,鉴于中心金属原子的未成对电子的差异(Fe II为4 ; Gd III为7 )非常接近与of(III)–DOTA(2.44 mM -1 s -1)的商业化MRI造影剂。由于g络合物始终是顺磁性的,因此无法在MRI中静音,因此本文介绍的基于Fe(II)的系统提供了开发响应性MRI探针的替代策略。
Contrast Agents for Magnetic Resonance Imaging
申请人:Hasserodt Jens
公开号:US20070218010A1
公开(公告)日:2007-09-20
The invention relates to contrast agents for magnetic resonance imaging comprising a chelating ligand and a transition metal ion, said ligand carrying a substituent capable of reacting chemically or biochemically with a target substance while bringing about a change in the spin state.
aqueous sample if it contains a molecular probe that responds to the addition of a chemicalanalyte by turning from a diamagnetic state into a paramagnetic one (off–on). We explore here a stable, low-spin, binary iron(II) complex that stores so much potential energy that its transformation by the target analyte leads to its fragmentation into a high-spin complex despite the imposing strength of the chelate
如果含水样品中含有一种分子探针,该分子探针通过从抗磁性状态转变为顺磁性状态(关-开)来响应化学分析物的添加,则可以在水性样品中建立顺磁性质。我们在这里探索了一种稳定的、低自旋的二元铁 (II) 复合物,该复合物存储了如此多的势能,尽管螯合效应的强度很大,但它被目标分析物的转化导致其碎裂成高自旋复合物。基础配体是混合胺,其成分可以自由变化以优化响应动力学,同时保留初始探针稳定性。随着唑组分离去基团特性的降低,探针稳定性提高,响应动力学降低。可以找到一种最佳排列,将吡唑与缺电子的芳香族甲醛组分(硝基取代)配对。与硝基还原为氨基相关的剧烈电子反转是观察到最初稳定的探针与还原性分析物反应时会迅速碎裂的主要原因。
Pyridyl-Based Pentadentate Ligands: Base-Catalyzed Hydrolysis of <i>a</i><i>sym</i>-[Co(dmptacn)Cl]<sup>2+</sup>
作者:W. Gregory Jackson、Alistair J. Dickie、Rajumati Bhula、Josephine A. McKeon、Leone Spiccia、Suzanne J. Brudenell、David C. R. Hockless、Anthony C. Willis
DOI:10.1021/ic040041m
日期:2004.10.1
perchlorate salt. The kinetics of base-catalyzed hydrolysis establishes the usual [OH(-)] dependence (k(OH) = 0.040 M(-1) s(-1), 25 degrees C, I = 1.0 M, NaCl), but D-exchange experiments reveal that substantial if not complete reaction proceeds via the new pseudoaminate mechanism, i.e., via deprotonation at an alpha-CH(2) center rather than the NH. The significant kinetic isotopeeffect (k(H)/k(D) = 2.1)