Bertrand Hélène C, Clède Sylvain, Guillot Régis, Lambert François, Policar Clotilde
Sorbonne Universités, UPMC Univ Paris 06 , UMR 7203, Laboratoire des Biomolécules, F-75005 Paris, France.
Inorg Chem. 2014 Jun 16;53(12):6204-23. doi: 10.1021/ic5007007. Epub 2014 Jun 6.
Octahedral d(6) low-spin Re(I) tricarbonyl complexes are of considerable interest as noninvasive imaging probes and have been deeply studied owing to their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. We reported recently the bimodal IR and luminescence imaging of a Re(I) tricarbonyl complex with a Pyta ligand (4-(2-pyridyl)-1,2,3-triazole) in cells and labeled such metal-carbonyl complexes SCoMPIs for single-core multimodal probes for imaging. Re(I) tricarbonyl complexes have unique photophysical properties allowing for their unequivocal detection in cells but also present some weaknesses such as a very low luminescence quantum yield in aqueous medium. Further optimizations would thus be desirable. We therefore developed new Re(I) tricarbonyl complexes prepared from different ancillary ligands. Complexes with benzothiadiazole-triazole ligands show interesting luminescent quantum yields in acetonitrile and may constitute valuable luminescent metal complexes in organic media. A series of complexes with bidentate 1-(2-quinolinyl)-1,2,3-triazole (Taquin) and 1-(2-pyridyl)-1,2,3-triazole (Tapy) ligands bearing various 4-substituted alkyl side chains has been designed and synthesized with efficient procedures. Their photophysical properties have been characterized in acetonitrile and in a H2O/DMSO (98/2) mixture and compared with those of the parent Quinta- and Pyta-based complexes. Tapy complexes bearing long alkyl chains show impressive enhancement of their luminescent properties relative to the parent Pyta complex. Theoretical calculations have been performed to further characterize this new class of rhenium tricarbonyl complexes. Preliminary cellular imaging studies in MDA-MB231 breast cancer cells reveal a strong increase in the luminescence signal in cells incubated with the Tapy complex substituted with a C12 alkyl chain. This study points out the interesting potential of the Tapy ligand in coordination chemistry, which has been so far underexploited.
八面体d(6)低自旋铼(I)三羰基配合物作为无创成像探针备受关注，由于其生物稳定性、低毒性、大斯托克斯位移和长发光寿命，已得到深入研究。我们最近报道了一种带有Pyta配体（4-(2-吡啶基)-1,2,3-三唑）的铼(I)三羰基配合物在细胞中的红外和发光双模态成像，并将此类金属羰基配合物标记为SCoMPIs用于单核多模态成像探针。铼(I)三羰基配合物具有独特的光物理性质，使其能够在细胞中被明确检测到，但也存在一些弱点，例如在水性介质中发光量子产率非常低。因此需要进一步优化。我们因此开发了由不同辅助配体制备的新型铼(I)三羰基配合物。带有苯并噻二唑-三唑配体的配合物在乙腈中显示出有趣的发光量子产率，并且可能在有机介质中构成有价值的发光金属配合物。已经设计并通过有效方法合成了一系列带有各种4-取代烷基侧链的双齿1-(2-喹啉基)-1,2,3-三唑（Taquin）和1-(2-吡啶基)-1,2,3-三唑（Tapy）配体的配合物。它们的光物理性质已在乙腈和H2O/DMSO（98/2）混合物中进行了表征，并与基于母体Quinta和Pyta的配合物进行了比较。带有长烷基链的Tapy配合物相对于母体Pyta配合物显示出其发光性质的显著增强。已经进行了理论计算以进一步表征这类新型铼三羰基配合物。在MDA-MB231乳腺癌细胞中的初步细胞成像研究表明，在用C12烷基链取代的Tapy配合物孵育的细胞中，发光信号有强烈增加。这项研究指出了Tapy配体在配位化学中有趣的潜力，而这种潜力迄今为止尚未得到充分利用。
