Luminescent Platinum(II) Dimers with a Cyclometallating Aryldiamine Ligand
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- 作者：Hershel Jude ; Jeanette A. Krause Bauer ; and William B. Connick
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：March 7, 2005
- 年：2005
- 卷：44
- 期：5
- 页码：1211 - 1220
- 全文大小：183K
- 年卷期：v.44,no.5(March 7, 2005)
- ISSN：1520-510X
文摘
Triflate salts of three (Pt(pip2NCN))2(
-L)2+ (pip2NCNH = 1,3-bis(piperidylmethyl)benzene) dimers bridged by aseries of nitrogen-donor ligands (L = pyrazine (pyz), 1,2-bis(4-pyridyl)ethane (bpa), trans-1,2-bis(4-pyridyl)ethylene(bpe)) are reported. These complexes have been fully characterized by 1H NMR spectroscopy and elementalanalysis. The X-ray crystal structures of [(Pt(pip2NCN))2(-pyz)](CF3SO3)2 and [(Pt(pip2NCN))2(-bpe)](CF3SO3)2·2CH2Cl2 are reported. [(Pt(pip2NCN))2(-pyz)](CF3SO3)2: triclinic, P
, a = 12.5240(5) Å, b = 14.1570(6) Å, c = 14.2928(6) Å, 
= 106.458(1)
, 
= 92.527(1), 
= 106.880(1), V = 2303.46(17) Å3, Z = 2. [(Pt(pip2NCN))2(-bpe)](CF3SO3)2·2CH2Cl2: monoclinic, P21/c, a = 10.1288(6) Å, b = 16.3346(9) Å, c = 17.4764(10) Å, =90.882(2), V = 2891.1(3) Å3, Z = 2. These structures and solution measurements provide evidence for thestrong trans-directing properties of the pip2NCN- ligand. The electronic structures of these complexes and thoseof the 4,4'-bipyridine (bpy) dimer, (Pt(pip2NCN))2(-bpy)2+, also have been investigated by UV-visible absorptionand emission spectroscopies, as well as cyclic voltammetry. The accumulated data indicate that variations in thebridging ligands provide remarkable control over the electronic structures and photophysics of these complexes.Notably, the bpa dimer exhibits a broad, low-energy emission from a metal-centered 3LF excited state, whereasthe bpe and bpy dimers exhibit structured emission from a lowest pyridyl-centered 3(
-*) excited state. In contrast,the pyz dimer exhibits remarkably intense yellow emission tentatively assigned to a triplet metal-to-ligand charge-transfer excited state.
-L)2+ (pip2NCNH = 1,3-bis(piperidylmethyl)benzene) dimers bridged by aseries of nitrogen-donor ligands (L = pyrazine (pyz), 1,2-bis(4-pyridyl)ethane (bpa), trans-1,2-bis(4-pyridyl)ethylene(bpe)) are reported. These complexes have been fully characterized by 1H NMR spectroscopy and elementalanalysis. The X-ray crystal structures of [(Pt(pip2NCN))2(-pyz)](CF3SO3)2 and [(Pt(pip2NCN))2(-bpe)](CF3SO3)2·2CH2Cl2 are reported. [(Pt(pip2NCN))2(-pyz)](CF3SO3)2: triclinic, P, a = 12.5240(5) Å, b = 14.1570(6) Å, c = 14.2928(6) Å, = 106.458(1), = 92.527(1), = 106.880(1), V = 2303.46(17) Å3, Z = 2. [(Pt(pip2NCN))2(-bpe)](CF3SO3)2·2CH2Cl2: monoclinic, P21/c, a = 10.1288(6) Å, b = 16.3346(9) Å, c = 17.4764(10) Å, =90.882(2), V = 2891.1(3) Å3, Z = 2. These structures and solution measurements provide evidence for thestrong trans-directing properties of the pip2NCN- ligand. The electronic structures of these complexes and thoseof the 4,4'-bipyridine (bpy) dimer, (Pt(pip2NCN))2(-bpy)2+, also have been investigated by UV-visible absorptionand emission spectroscopies, as well as cyclic voltammetry. The accumulated data indicate that variations in thebridging ligands provide remarkable control over the electronic structures and photophysics of these complexes.Notably, the bpa dimer exhibits a broad, low-energy emission from a metal-centered 3LF excited state, whereasthe bpe and bpy dimers exhibit structured emission from a lowest pyridyl-centered 3(-*) excited state. In contrast,the pyz dimer exhibits remarkably intense yellow emission tentatively assigned to a triplet metal-to-ligand charge-transfer excited state.