Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, South Africa, 9300.
Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
Dalton Trans. 2021 Dec 7;50(47):17506-17514. doi: 10.1039/d1dt03234h.
A novel proof-of-concept is reported to modify the water solubility and potential biological effects of a bis(diphenylphosphino)alkylamine (PNP) ligand and the corresponding metal complex, by introducing an amine group on the outer periphery of the pendant ligand arm. Thus, a tertiary butoxycarbonyl protected '-Boc-ethylenediamine-,-bis(diphenylphosphino) ('-Boc-PNP) ligand (1) was synthesized by reacting the protected ethylenediamine and chlorodiphenylphosphine in a 1 : 2 molar ratio. The corresponding -[Re(CO)('-Boc-PNP)Br] (1A) complex was then obtained by reacting '-Boc-PNP (1) with (EtN)-[Re(CO)Br] in equimolar amounts in DCM at 50 °C. De-protection of the '-Boc pendant amine group in 1A with TFA leads to -[Re(NH-PNP)(CO)Br]·CFCOO (1B) which is soluble in DO (>0.05 M). Treating 1B with saturated aqueous NaHCO yields -[Re(NH-PNP)(CO)Br]·MeOH (1C) in near quantitative yield. Although both 1A and 1C are not soluble in DO, addition of TFA easily generates 1B (P NMR), confirming the formation of the protonated amine. Isolation of -[Tc(CO)(-Boc-PNP)(Cl)] (1D) confirmed that the rhenium and technetium (Tc) can be easily interchanged in this process. Reported are hence the unique rhenium series of compounds 1A, 1B and 1C and the corresponding technetium complex 1D, unequivocally characterized by single crystal XRD, as well as IR and H NMR spectroscopy. Preliminary antimicrobial evaluation indicates that ligand 1 and its respective rhenium complexes (1A-1C) were not active against selected fungi () and bacteria (, , , and ). These types of ligands and complexes therefore present themselves as excellent radio models for further evaluation using Re, Re and Tc to potentially study the toxicity of appropriately designed complexes.
报道了一种通过在悬垂配体臂的外围引入氨基来修饰双（二苯基膦）烷基胺（PNP）配体及其相应金属配合物的水溶性和潜在生物学效应的新概念验证。因此，通过反应保护的乙二胺和氯二苯基膦以 1:2 摩尔比合成了叔丁氧羰基保护的 '-Boc-乙二胺-，-双（二苯基膦）（'-Boc-PNP）配体（1）。然后，通过将'-Boc-PNP（1）与（EtN）-[Re（CO）Br]以等摩尔量在 50°C 的 DCM 中反应，得到相应的 -[Re（CO）（'-Boc-PNP）Br]（1A）配合物。1A 中'-Boc 侧链伯胺基团的脱保护用 TFA 进行，得到在 DO（>0.05 M）中可溶的 -[Re（NH-PNP）（CO）Br]·CFCOO（1B）。用饱和碳酸氢钠水溶液处理 1B 可得到近定量产率的 -[Re（NH-PNP）（CO）Br]·MeOH（1C）。尽管 1A 和 1C 都不溶于 DO，但加入 TFA 很容易生成 1B（P NMR），证实了质子化胺的形成。 -[Tc（CO）（-Boc-PNP）（Cl）]（1D）的分离证实了该过程中铼和锝（Tc）可以很容易地相互交换。因此，报道了独特的铼系列化合物 1A、1B 和 1C 以及相应的锝配合物 1D，通过单晶 XRD 以及 IR 和 H NMR 光谱进行了明确的表征。初步的抗菌评估表明，配体 1 及其相应的铼配合物（1A-1C）对选定的真菌（）和细菌（，，，和）均无活性。这些类型的配体和配合物因此成为进一步使用 Re、Re 和 Tc 进行评估的优秀放射性模型，以潜在地研究适当设计的配合物的毒性。
