Energy-transfer rate in crystals of double-complex salts composed of [RU(N-N)(3)](2+) (N-N=2,2 '-bipyridine or 1,10-phenanthroline) and [Cr(CN)(6)](3-): Effect of relative orientation between donor and acceptor

Citation
T. Otsuka et al., Energy-transfer rate in crystals of double-complex salts composed of [RU(N-N)(3)](2+) (N-N=2,2 '-bipyridine or 1,10-phenanthroline) and [Cr(CN)(6)](3-): Effect of relative orientation between donor and acceptor, INORG CHEM, 40(14), 2001, pp. 3406-3412
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
INORGANIC CHEMISTRY
ISSN journal
0020-1669 → ACNP
Volume
40
Issue
14
Year of publication
2001
Pages
3406 - 3412
Database
ISI
SICI code
0020-1669(20010702)40:14<3406:ERICOD>2.0.ZU;2-X
Abstract
A block single-crystal was obtained using a diffusion method with a concent rated acetone-water(vol. 1/1) solution of [Ru(phen)(3)]Cl-2. 6H(2)O (phen = 1,10-phenanthroline) and a concentrated aqueous solution of K-3[Cr(CN)(6)] , without evaporating solvents. The crystal was identified as a double-comp lex salt including two acetone and fourteen solvent water molecules, [Ru(ph en)(3)](2)[Cr(CN)(6)]Cl .2(CH3)(2)CO . 14H(2)O (1). Measurement of the X-ra y diffraction pattern of the double-complex salt was performed using an X-r ay diffractometer with an Imaging-Flare (IP) Weissenberg camera. 1 crystall izes in the triclinic space group P (1) over bar, with a = 13.930(5) Angstr om, b = 14.783(5) Angstrom, c = 11.137(6) Angstrom, alpha = 89.87(4)degrees , beta = 107.47(3)degrees gamma = 96.68(3)degrees, and Z = 2. The crystal s tructure is very different from that of [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl . 8H(2 )O (2) (bpy = 2,2 ' -bipyridine), which could be obtained using the same pr ocedure and crystallizes in the monoclinic space group C2, with a = 22.414( 2) Angstrom, b = 13.7686(15) Angstrom, c = 22.207(2) Angstrom, beta = 90.71 3(8)degrees, and Z = 4. The distance between the central-metal ions of ruth enium(II) and chromium(III) complexes in [Ru(phen)(3)](2)[Cr(CN)(6)]Cl .2(C H3)(2)CO . 14H(2)O (7.170 Angstrom) is shorter than that in [Ru(bPY)(3)](2) [Cr(CN)(6)]Cl . 8H(2)O (9.173 Angstrom) by about 2 Angstrom, while the rate of energy transfer from the (MLCT)-M-3 state of [Ru(N-N)(3)](2+) to the E- 2(g) state of [Cr(CN)(6)](3-) in the former salt (9.5 x 10(5) s(-1)) is far slower than that in the latter one (6.0 x 10(6) s(-1)) at 77 K. These resu lts indicate that the energy-transfer rate strongly depends, not upon the d istance between central metal ions, rather, upon the mutual relative orient ation between the donor and the acceptor complexes in double-complex salts.