Sensitization of lanthanide luminescence by two different Pt → Ln energy transfer pathways in PtLn3 heterotetranuclear complexes with 5-ethynyl-2,2′-bipyridine
作者:Hai-Bing Xu、Li-Yi Zhang、Zhong-Hui Chen、Lin-Xi Shi、Zhong-Ning Chen
DOI:10.1039/b801573b
日期:——
Reactions of 5-[2-(trimethylsilyl)-1-ethynyl]-2,2â²-bipyridine (Me3SiCCbpy) with Pt(bpy)Cl2 (bpy = 2,2â²-bipyridine) and Pt(bpyCCâCCbpy)Cl2 (bpyCCâCCbpy = bis(2,2â²-bipyridin-5-yl)butadiyne) induced isolation of Pt(bpy)(CCbpy)2 (1) and Pt(bpyCCâCCbpy)(CCbpy)2 (5), respectively. Incorporating Ln(hfac)3(H2O)2 (hfac = hexafluoroacetylacetone) with 1 or 5 gave the corresponding PtLn2 (Ln = Nd (2), Eu (3), Yb (4)) or PtLn3 arrays (Ln = Nd (6), Eu (7), Gd (8), Yb (9)). With excitation at 360 ⤠λex ⤠480 nm, which is the MLCT absorption region of the Pt(2,2â²-bipyridyl)(acetylide)2 chromophore, sensitized lanthanide luminescence is successfully attained by efficient Pt â Ln energy transfer from the PtII antenna chromophores. In contrast with quite efficient Pt â Ln energy transfer in the PtâCCbpyâLn (Ptâ¯Ln = 8.6 Ã
) array, energy transfer transmitted across the PtâbpyCCâCCbpyâLn (Ptâ¯Ln = 13.3 Ã
) array is less efficient owing to the much longer Ptâ¯Ln separation in the latter.
5-[2-(trimethylsill)-1-ethynyl]-2,2â²-bipyridine (Me3SiCCbpy) 与 Pt(bpy)Cl2 (bpy = 2,2â²-bipyridine) 和 Pt(bpyCCâCCbpy)Cl2 (bpyCCâCCbpy = bis(2. 2â²-bipyridin-5-yl)butadiyne) 的反应诱导分离出 Pt(bpy)(CCbpy)2 (1) 和 Pt(bpyCCâCCbpy) (2)、2,2â²-联吡啶-5-基)丁二炔)分别诱导分离出 Pt(bpy)(CCbpy)2 (1) 和 Pt(bpyCCâCCbpy)(CCbpy)2 (5)。将 Ln(hfac)3(H2O)2(hfac = 六氟乙酰丙酮)与 1 或 5 结合,可得到相应的 PtLn2(Ln = Nd (2)、Eu (3)、Yb (4))或 PtLn3 阵列(Ln = Nd (6)、Eu (7)、Gd (8)、Yb (9))。铂(2,2â²-联吡啶)(乙酰基)2发色团的MLCT吸收区为360⤠Π"ex⤠480纳米,在此激发下,通过从PtII天线发色团进行高效的PtâLn能量转移,成功实现了敏化镧系元素发光。与PtâCCbpyâLn(Ptâ¯Ln = 8.6 Ã)阵列中相当高效的PtâLn能量转移相比,PtâbpyCCâCCbpyâLn(Ptâ¯Ln = 13.3 Ã)阵列中的能量转移效率较低,原因是后者的Ptâ¯Ln间距更长。