2,2 -bipyridyl cyanides

The versatility of cyanide and bipyridyl ligands has been used to stabilize low oxidation states. By using potassium in liquid ammonia, K3Ti (CN)6 is reduced to K2Ti (CN)4 and TiBt3 - - KCN to K4Ti°(CN)4. With ZrBt3 and M CN (M = K, Rb) in liquid ammonia, ammonolysis occurs and zerovalent Zr is produced ... 

Table XVI shows a selection of stability constants and redox potentials for iron(II) and iron(III) complexes. This Table covers a wide range of the latter, showing how the relative stabilities of the iron(II) and iron(III) complexes are refiected in. B (Fe /Fe ) values. A more detailed illustration is provided by the complexes of a series of linear hexadentate hydroxypyridinonate and catecholate ligands, where again high stabilities for the respective iron(III) complexes are refiected in markedly negative redox potentials (213). The combination of the high stabilities of iron(III) complexes of hydrox5rpyridinones, as of hydroxamates, catecholates, and siderophores, and the low stabilities of their iron(II) analogues is also apparent in Fig. 8. Here redox potentials for hydroxypyranonate and hydroxypyridinonate complexes of iron are placed in the overall context of redox potentials for iron(III)/iron(II) couples. The -(Fe /Fe ) range for e.g., water, cyanide, edta, 2,2 -bipyridyl, and (substituted) 1,10-phenanthrolines is...

The standard electrode potentials, E°(V) for some chelates of the Fe /Fe redox couple areas follows o-phenanthroline, 1.20 2,2 -bipyridyl 1.096 water, 0.77 cyanide, 0.10 oxalate, -0.01 and 8-hydroquinone, -0.15 (Latimer, 1952). In the case of bipyridyl... 

Both the cyanide, [Au(CN)2] , and fulminate, [Au(CNO)2] , ions contain linear gold(I) centres.387,388 A report that KAu(CN)2(2,2 -bipyridyl) contains square planar gold(I) has been disproved the bipy ligand is not coordinated to gold and the complex contains linear [Au(CN)2J ions. 390 AuCN is polymeric with a linear (—Au—CN—) Au— chain structure.391... 

Other aqueous preparative methods include aerial oxidation of an alkaline solution of CoS04 and NaCNO to give the fulminatocobaltate(III) anion [Co(CNO)6]3-, reduction of ruthenate(VI) by excess of fulminate to give [Ru(CNO)6]4, and displacement of 2,2 -bipyridyl or 1,10-phenan-throline from nickel(II) or cobalt(III) complexes to give [Ni(CNO)4]2 or [Co(CNO)6]3. Liquid ammonia may replace water as solvent [Ni(NH3) ]2+ and [Co(NH3)6]3+, for example, react with sodium fulminate in this solvent to form [Ni(CNO)4]2 and [Co(CNO)6]3. In all these reactions fulminate behaves very like cyanide with [AuClJ-, however, reduction to form the gold(I) complex [Au(CNO)2] takes place and no gold(III) complex can be isolated. 

Dyes such as erythrosin B [172], eosin [173-177], rose bengal [178,179], rhodamines [180-185], cresyl violet [186-191], thionine [192], chlorophyll a and b [193-198], chlorophyllin [197,199], anthracene-9-carboxylate [200,201], perylene [202,203] 8-hydroxyquinoline [204], porphyrins [205], phthalocyanines [206,207], transition metal cyanides [208,209], Ru(bpy)32+ and its analogs [83,170,210-218], cyanines [169,219-226], squaraines [55,227-230], and phe-nylfluorone [231] which have high extinction coefficients in the visible, are often employed to extend the photoresponse of the semiconductor in photoelectro-chemical systems. Visible light sensitization of platinized Ti02 photocatalyst by surface-coated polymers derivatized with ruthenium tris(bipyridyl) complex has also been attempted [232,233]. Because the singlet excited state of these dyes is short lived it becomes essential to adsorb them on the semiconductor surface with... 

The compound m-[Ru(CN)2(bipy)2] 3H20 was first prepared from NaCN, 2,2 -bipyridyl and K2[RuCl5(OH2)] followed by reduction with bisulfite ion. Tt is protonated on the cyanide nitrogen atoms by perchloric acid in acetic acid40 and its IR spectrum has been recorded and discussed.41 An alternative synthesis from reaction of [Ru(C204)(bipy)2] 4H20 with NaCN is available.42... 

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