TY - JOUR
T1 - Photophysical and structural properties of cyanoruthenate complexes of hexaazatriphenylene
AU - Herrera, Juan Manuel
AU - Pope, Simon J.A.
AU - Meijer, Anthony J.H.M.
AU - Easun, Timothy L.
AU - Adams, Harry
AU - Alsindi, Wassim Z.
AU - Sun, Xue Zhong
AU - George, Michael W.
AU - Faulkner, Stephen
AU - Ward, Michael D.
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2007/9/19
Y1 - 2007/9/19
N2 - The tritopic bridging ligand hexaazatriphenylene (HAT) has been used to prepare the mono-, di-, and trinuclear cyanoruthenate complexes [Ru(CN) 4(HAT)]2- ([1]2-), [{Ru(CN)4} 2(μ2-HAT)]4- ([2]4-), and [{Ru(CN)4}3(μ3-HAT)]6- ([3] 6-). These complexes are of interest both for their photophysical properties and ability to act as sensitizers, associated with strong MLCT absorptions; and their structural properties, with up to 12 externally directed cyanide ligands at a single "node" for preparation of coordination networks. The complexes are strongly solvatochromic, with broad and intense MLCT absorption manifolds arising from the presence of low-lying π* orbitals on the HAT ligand, as confirmed by DFT calculations; in aprotic solvents [3]6- is a panchromatic absorber of visible light. Although nonluminescent in fluid solution, the lowest MLCT excited states have lifetimes in D2O of tens of nanoseconds and could be detected by time-resolved IR spectrosocopy. For dinuclear [2]4- and trinuclear [3]6- the TRIR spectra are indicative of asymmetric MLCT excited states containing distinct Ru(III) and Ru(II) centers on the IR time scale. The complexes show red 3MLCT luminescence as solids and in EtOH/MeOH glass at 77 K. Ln(III) salts of [1]2-, [2]4-, and [3]6- form infinite coordination networks based on Ru-CN-Ln bridges with a range of one-, two-, and three-dimensional polymeric structures. In the Yb(III) and Nd(III) salts of [3]6- the complex anion forms an 8-connected node. Whereas all of the Gd(III) salts show strong 3MLCT luminescence in the solid state, the Ru-based emission in the Nd(III) and Yb(III) analogues is substantially quenched by Ru → Ln photoinduced energy transfer, which results in sensitized near-infrared luminescence from Yb(III) and Nd(III).
AB - The tritopic bridging ligand hexaazatriphenylene (HAT) has been used to prepare the mono-, di-, and trinuclear cyanoruthenate complexes [Ru(CN) 4(HAT)]2- ([1]2-), [{Ru(CN)4} 2(μ2-HAT)]4- ([2]4-), and [{Ru(CN)4}3(μ3-HAT)]6- ([3] 6-). These complexes are of interest both for their photophysical properties and ability to act as sensitizers, associated with strong MLCT absorptions; and their structural properties, with up to 12 externally directed cyanide ligands at a single "node" for preparation of coordination networks. The complexes are strongly solvatochromic, with broad and intense MLCT absorption manifolds arising from the presence of low-lying π* orbitals on the HAT ligand, as confirmed by DFT calculations; in aprotic solvents [3]6- is a panchromatic absorber of visible light. Although nonluminescent in fluid solution, the lowest MLCT excited states have lifetimes in D2O of tens of nanoseconds and could be detected by time-resolved IR spectrosocopy. For dinuclear [2]4- and trinuclear [3]6- the TRIR spectra are indicative of asymmetric MLCT excited states containing distinct Ru(III) and Ru(II) centers on the IR time scale. The complexes show red 3MLCT luminescence as solids and in EtOH/MeOH glass at 77 K. Ln(III) salts of [1]2-, [2]4-, and [3]6- form infinite coordination networks based on Ru-CN-Ln bridges with a range of one-, two-, and three-dimensional polymeric structures. In the Yb(III) and Nd(III) salts of [3]6- the complex anion forms an 8-connected node. Whereas all of the Gd(III) salts show strong 3MLCT luminescence in the solid state, the Ru-based emission in the Nd(III) and Yb(III) analogues is substantially quenched by Ru → Ln photoinduced energy transfer, which results in sensitized near-infrared luminescence from Yb(III) and Nd(III).
UR - http://www.scopus.com/inward/record.url?scp=35048872831&partnerID=8YFLogxK
U2 - 10.1021/ja072672w
DO - 10.1021/ja072672w
M3 - Article
C2 - 17713906
AN - SCOPUS:35048872831
SN - 0002-7863
VL - 129
SP - 11491
EP - 11504
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 37
ER -