具不同軸取代之脯胺醇配位基於含鎳超氧化物歧化酶擬態化合物之合成、鑑定及對超氧離子活性探討

Abstract

本實驗室之前發表了Ni(BDPP)作為NiSOD 的擬態化合物，而本研究為了改良擬態化合物對超氧離子的活性及提升配位基的可變性，利用2,6-bis(((S)-2-(bis(4-methylphenyl)hydroxymethyl)-1-pyrrolidinyl)-methyl)-pyridine (H2BDPMeP) 及(S, S)-bis[2-(diphenylmethanol)-pyrrolidine]dipropylaniline (H2BDPPA) 兩種配位基， 分別得到了Ni(BDPMeP) (1)、[Ni(HBDPMeP)](ClO4)·(CH2Cl2)2 (2)和Ni2(BDPPA)2 (3)等幾種不同的NiSOD 擬態化合物。這些NiSOD 擬態化合物以X 光單晶繞射儀、紫外光可見光光譜儀及循環伏安法所鑑定。錯合物1 為Ni(BDPP) 的衍生物， 其在249.5 mV (versus Ag/AgCl inDCM, E = 124 mV)有一可逆的NiIII/NiII 氧化還原峰，而錯合物3 在714 mV (versus Ag/AgCl in DCM, E = 192 mV)也顯示了一組准可逆的NiIII/NiII 氧化還原峰，由錯合物1 和3 的電化學分析可知，他們可藉由二茂鐵離子或1,1’-二溴二茂鐵離子氧化生成三價鎳錯合物[NiIII(BDPMeP)](BF4) (4)及NiIII2(BDPPA)2(BF4)2 (5)。更重要的是錯合物4 和5 能將超氧離子轉化為氧氣，並分別還原回二價鎳錯合物1和3。Recently, the complex Ni(BDPP) was reported as a NiSOD model compound. In this study, we would like to improve the superoxidere activity of the NiSOD mimics and to augment the ligand alterability. The alternative NiSOD model compounds, Ni(BDPMeP) (1),[Ni(HBDPMeP)](ClO4)·(CH2Cl2)2 (2), and Ni2(BDPPA)2 (3), were supported by a new ligand, 2,6-bis(((S)-2-(bis(4-methylphenyl)-hydroxymethyl)-1-pyrrolidinyl)methyl)-pyridine (H2BDPMeP) or (S,S)-bis[2-(diphenylmethanol)- pyrrolidine]dipropylaniline (H2BDPPA),respectively. These NiSOD mimics were characterized by X-raycrystallography, UV-vis spectroscopy, and cyclic voltammetry. Complex1, a derivative of Ni(BDPP), demonstrated a reversible NiIII/NiII redoxcouple at E1/2 = 249.5 mV versus Ag/AgCl in DCM (ΔE = 124 mV). In addition, complex 3 showed a quasi-reversible NiIII/NiII redox couple atE1/2 = 714 mV versus Ag/AgCl in DCM (ΔE = 192 mV). Complex 1 and3 can be oxidized to nickel(III) species, [NiIII(BDPMeP)](BF4) (4) and NiIII2(BDPPA)2(BF4)2 (5), by ferrocenium salt and 1,1’-dibromoferrocenium salt respectively. Importantly, complexes 4 and 5 have shown the ability to convert O2– into O2 along with the formation of 1 and 3.