Sensitised near-infrared luminescence from lanthanide(III) centres using Re(I) and Pt(II) diimine complexes as energy donors in d-f dinuclear complexes based on 2,3-bis(2-pyridyl)pyrazine.
Sensitised near-infrared luminescence from lanthanide(III) centres using Re(I) and Pt(II) diimine complexes as energy donors in d-f dinuclear complexes based on 2,3-bis(2-pyridyl)pyrazine.
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DOI：
10.1039/b616423d
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发表时间：
2007-04
影响因子：
4
通讯作者：
Frazer Kennedy;N. M. Shavaleev;Thelma Koullourou;Zöe R. Bell;J. Jeffery;S. Faulkner;M. Ward
中科院分区：
文献类型：
--
作者：
Frazer Kennedy;N. M. Shavaleev;Thelma Koullourou;Zöe R. Bell;J. Jeffery;S. Faulkner;M. Ward
本文报道了过渡金属配合物[Re（CO）（3）Cl（bppz）]和[Pt（CC-C（6）H（4）CF（3））（2）（bppz）] [bppz = 2，3-bis（2-吡啶基）吡嗪]，其中潜在的桥连配体BPPZ的二亚胺结合位点之一是空的，已被用作“配合物配体”，通过在空位处连接{Ln（dik）（3）}片段（dik = 1，3-二酮化物）来制备异双核d-f配合物。当Ln = Pr、Nd、Er或Yb时，镧系元素中心具有低能f-f激发态，其能够从Pt（II）或Re（I）中心的（3）MLCT激发态接受能量，猝灭（3）MLCT发光并在近红外区域提供敏化的镧系元素（III）基发光。UV/维斯和发光光谱滴定允许测量（i）{Ln（dik）（3）}片段在[Re（CO）（3）Cl（bppz）]或[Pt（CC-C（6）H（4）CF（3））（2）（bppz）]的空二亚胺位点处结合的缔合常数，和（ii）根据Ln（III）中心的性质的（3）MLCT发光的淬灭程度。在所有情况下，发现Nd（III）在猝灭d区组分的（3）MLCT发光方面是系列中最有效的，因为适当能量的f-f激发态的高密度使其成为特别有效的能量受体。
The luminescent transition metal complexes [Re(CO)(3)Cl(bppz)] and [Pt(CC-C(6)H(4)CF(3))(2)(bppz)] [bppz = 2,3-bis(2-pyridyl)pyrazine], in which one of the diimine binding sites of the potentially bridging ligand bppz is vacant, have been used as 'complex ligands' to make heterodinuclear d-f complexes by attachment of a {Ln(dik)(3)} fragment (dik = a 1,3-diketonate) at the vacant site. When Ln = Pr, Nd, Er or Yb the lanthanide centre has low-energy f-f excited states capable of accepting energy from the (3)MLCT excited state of the Pt(II) or Re(I) centre, quenching the (3)MLCT luminescence and affording sensitised lanthanide(III)-based luminescence in the near-IR region. UV/Vis and luminescence spectroscopic titrations allowed measurement of (i) the association constants for binding of the {Ln(dik)(3)} fragment at the vacant diimine site of [Re(CO)(3)Cl(bppz)] or [Pt(CC-C(6)H(4)CF(3))(2)(bppz)], and (ii) the degree of quenching of the (3)MLCT luminescence according to the nature of the Ln(III) centre. In all cases Nd(III) was found to be the most effective of the series at quenching the (3)MLCT luminescence of the d-block component because the high density of f-f excited states of the appropriate energy make it a particularly effective energy-acceptor.