的宏环复合物 (Fe(III) 与混合基和酸或胺作为T1MRI探头的悬挂
Elizabeth A Kras1, Roy Cineus1, Matthew R Crawley1
1Department of Chemistry, University at Buffalo, the State University of New York, Amherst, NY 14260, USA. jmorrow@buffalo.edu.
Dalton transactions (Cambridge, England : 2003)
|February 6, 2024
概括
新的高旋铁 (III) 复合物显示出作为T1MRI对比剂的前景. 由于酸盐质子化,Fe (PTOB) 在酸性pH下表现出增强的放松性,这表明有针对性成像的潜力.
科学领域:
- 协调化学 协调化学
- 磁共振成像 (MRI) 对比剂对比剂
- 无机化学 无机化学
背景情况:
- 新型T1MRI对比剂的开发对于增强的诊断成像至关重要.
- 铁 (III) 复合物由于其对磁性特性而具有潜力.
- 1,4,7-triazacyclononane (TACN) 连接物为金属离子提供稳定的协调环境.
研究的目的:
- 为T1MRI应用合成和表征高旋转Fe(III) 复合物与混合氧供体吊.
- 研究连接体结构,特别是第三个悬挂组的存在对复杂性质的影响.
- 评估这些Fe (III) 复合物的溶液化学,放松性和结构特征.
主要方法:
- 合成Fe(III) 复合物与1,4,7-triazacyclononane (TACN) 和基,酸或胺.
- 溶液研究包括pKa的确定和氧化还原潜力的测量.
- 用于结构阐明的X射线晶体学.
- 在不同的pH值和磁场强度下测量放松度 (r1).
主要成果:
- (PTOB) 呈现两种电离 (酸的pKa为1.7,基的pKa为6.3); (TOAB) 呈现一种电离 (基的pKa为7.0).
- [Fe(PTOB) ]Br2的X射线结构显示了一个扭曲的八面体几何.
- 在各种具有挑战性的条件下,Fe (PTOB) 和Fe (TOAB) 都是动态惰性的.
- Fe(TOAB) 显示较低的r1缓解率 (0.6mM-1s-1在1.4T);Fe(PTOB) 显示较高的r1缓解率 (2.5mM-1s-1在酸性pH).
- 在酸性pH下Fe (PTOB) 的放松性增加归因于酸盐质子化.
结论:
- 研究的Fe(III) -TACN复合体是稳定的,适合作为MRI探针进行研究.
- Fe ((PTOB) 显示了pH依赖的放松性,提供了针对性或响应性MRI的潜力.
- 体设计,特别是酸盐组,显著影响MRI对比性质.
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