scholarly journals X-ray Structure Analysis and the Intervalent Electron Transfer in Organic Mixed-Valence Crystals with Bridged Aromatic Cation Radicals

2002 ◽  
Vol 124 (5) ◽  
pp. 843-855 ◽  
Author(s):  
Sergey V. Lindeman ◽  
Sergiy V. Rosokha ◽  
Duoli Sun ◽  
Jay K. Kochi
1987 ◽  
Vol 42 (10) ◽  
pp. 1298-1306 ◽  
Author(s):  
Dieter Sellmann ◽  
Gerhard Binker ◽  
Falk Knoch

Abstract In order to investigate the specific properties which are associated with metal sulfur cen­ters, the system Ru/S2C6H42- has been studied with respect to the synthesis of new com­plexes and their reactions as well as their structure. cis-(NBu4)(Ru(NO))(PMe4)(S2C6H4)2] reacts with an excess of PMe3 in boiling THF to give the paramagnetic (μeff = 0,96 B. M., 295 K) trans-(NBu4)(Ru(PMe4)2(S2C6H4)2) (I). A plausible intermediate in this reaction is the nitrido complex (NBu4)(Ru(N)(S2C6H4)2) (2) since 2 gives with one equivalent of PMe3 a very labile product which is probably (NBu4)(Ru(N)(PMe4)(S2C6H4)2) (3). but reacts with an excess of PMe3 even at 20 °C to give 1. The Ru(III) complex 1 is easily oxidized by O2 or PhN2BF4 to yield the diamagnetic Ru(IV) species trans-(Ru(PMe3)2(S2C6H4)2) (4). Remarkably, the transformation of 1 into 4 is achieved also by H+ ions, providing a model reaction for the coupled H+-electron transfer which has been discussed for substrate reactions at metal sulfur centers of enzymes. - The reaction of RuCl2(PMe3)4 with S2C6H42- yields [Ru(PMe3)4(S2C6H4)] (5) at 20 °C, even if an excess of S2C6H42- is applied. Upon heating in THF or EtOH, 5 looses one PMe3 ligand to give the 16e -complex [Ru(PMe4)4(S2C6H4)] (6) which rapidly coordinates CO to give [Ru(CO)(PMe4)4(S2C6H4)] (7); '1P NMR indicates a meridional coordination of PMe4 in 7, and consequently CO must be trans to S2C6H42-. 6 reacts also with LiAlH4 to yield a very sensitive hydride complex to which the tentative formula [Ru(H)2(PMe3)2(S2C6H4)] is assigned. All compounds were characterized by elemental analyses and spectroscopic means, the structures of I and 5 were determined by X-ray structure analysis.


1976 ◽  
Vol 31 (9) ◽  
pp. 1285-1286 ◽  
Author(s):  
G. Birke ◽  
H. P. Latscha ◽  
H. Pritzkow

The reaction between isopropylamine and isopropylammonium hexachloroantimonate(V) yields a red product of the composition C12H40Cl8N4Sb. The X-ray structure analysis showed that this is a mixed valence compound of SbCl63- and SbCl6- octahedra.


2018 ◽  
Vol 74 (11) ◽  
pp. 1487-1494 ◽  
Author(s):  
Brandon Derstine ◽  
Carmen Chamberlain ◽  
Morgan Glover ◽  
Lindsey Porter ◽  
Amanda Eckermann

The triruthenium oxo clusters [Ru3(OAc)6O(L)3]+ and [Ru3(OAc)6O(L)2(CO)] possess unique electronic characteristics that vary based on the ligands L. Here we report an investigation of the structural, electrochemical, and optical properties of clusters with imidazole, benzimidazole, and 4-phenylpyridine ligands. The complexes [Ru3(OAc)6O(L)3]+ [1+ : L = imidazole (im); 2+ : L = benzimidazole (benzim); 3+ : L = 4-phenylpyridine (4PP)] and [Ru3(OAc)6O(L)2(CO)] (1-CO and 3-CO) were synthesized by reaction of either [Ru3(OAc)6O(MeOH)3]+ or [Ru3(OAc)6O(MeOH)2(CO)], respectively, with the corresponding heterocycle. We further discovered that [3]OAc could be reduced to the mixed-valence neutral state 3 by refluxing the complex under nitrogen in methanol. Single-crystal X-ray structure analysis of hexa-μ2-acetato-μ3-oxido-tris(1H-imidazole)triruthenium hexafluorophosphate acetonitrile hemisolvate, [Ru3(C2H3O2)6O(C3H4N2)3]PF6·0.5CH3CN, [1]PF6 , hexa-μ2-acetato-carbonylbis(1H-imidazole)-μ3-oxido-triruthenium methanol monosolvate, [Ru3(C2H3O2)6O(C3H4N2)(CO)]·CH3OH, 1-CO, hexa-μ2-acetato-μ3-oxido-tris(4-phenylpyridine)triruthenium pentahydrate, [Ru3(C2H3O2)6O(C11H9N)3]·5H2O, 3, and hexa-μ2-acetato-carbonyl-μ3-oxido-bis(4-phenylpyridine)triruthenium methanol monosolvate, [Ru3(C2H3O2)6O(C11H9N)2(CO)]·CH3OH, 3-CO, show the expected triruthenium μ3-oxo core and N-coordination of the ligands. Cyclic voltammetry revealed quasi-reversible and irreversible redox couples in [1]PF6 , 1-CO, and [2]PF6 , while [3]PF6 and 3-CO exhibit reversible redox couples. The optical properties of these richly colored species were investigated using UV–Vis spectroscopy.


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