Synthesis, Characterization, Co-Releasing And Luminescence Properties Of Transition Metals And Rare Earth-Transition Metals Carbonyl Complexes With N-Heterocyclic Ligands

Carbon monoxide (CO) is an important signaling molecule in organisms, playing an important role in many fields, such as regulating blood pressure, anti-inflammatory, anti-cell death, and organ transplant protection. Transition metal carbonyl complexes as CO carrier have drawn widely attention in biology and medical fields because of their advantage of low toxicity and good CO releasing performance.On the other hand, rare earth ion (Ln3+) functional compounds have aroused fast growing interests due to their unique electron structure and were widly applied in the fields of bioimaging, environmental catalytic, lighting, fluorescence immunoassay and medicine. Based on the applications in the biologic field of transition metal carbonyl complexes as CO carrier and rare earth luminescent materials, we carried out the work as follows.Firstly,20 new transition metal carbonyl complexes (1a～7a, 1b～7b, 1c, 3c～7c)were obtained by reactions of simple Mo、Rh、Ru carbonyl complexes with N-heterocyclic ligands L1～L7 using mild solvo-reflux method, respectively. The results of myoglobin assay reveal that 11 new carbonyl complexes can be used as the carbon monoxide releasing molecules.Secondly, rare earth metal complexes [LnLl](Ln=Eu、Tb and Nd) (1d-3d) were prepared by mild solvothermal method. X-ray single crystal diffraction analyses show that they all have the same crystal structures and good luminescence properties. By changing the ratio of the doped rare earth ions Eu3+/Tb3+, a series of adjustable luminescent complexes eventually be obtained. In addation, five new single nuclear rare earth complexes le-5e and one binuclear rare earth Eu3+complexes 6e were also obtained by reactions of L5 and L7 with the corresponding rare earth nitrate. The luminescence properties of them have been investigated.Finally, based on the good luminescence properties of L5 coordinated rare earth complexes le-5e,15 new rare earth-transition metal carbonyl complexes [RhLn]L5 (1f～5f), [RuLn]L5 (lg～5g), [MnLn]L5 (1h～5h), were synthesized by reactions of [RhCl(CO)2]2 (Ⅱ), [Ru(η3-C3H5)(CO)3Br] (Ⅲ), Mn(CO)5Br (IV) with Ln(NO3)3·6H2O(Sm3+, Eu3+, Tb3+, Nd3+ and Yb3+) by mild solvo-reflux method, respectively. All complexes were characterized by IR,1H-NMR, elemental analysis and MS. The properties of CO-releasing and luminescence were investigated by the myoglobin assay mathod in pure buffer illustrate and fluorescence spectra, respectively. The results show that Sm3+and Eu3+ can increase the release of CO, but Nd3+ and Yb3+ degrade the release of CO. Fluorescence spectra of these rare earth-transition metal carbonyl complexes show that the characteristic emission bands of Sm3+and Eu3+ are detectable and the complexes containing Ru and Mn have better luminescent performance, which can be used as the CO release molecules with fluorescently labeled function for further study.