TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Definitions:    M = Ru(II) or Os(II);    A1, A2 = COOH, -COON(C4H9)4, -PO(OH)2, provided that any one of A1 and A2 is different from H;    X = NCS or CN;    Y2 = pentane-2,4-dione, 3-methyl-pentane-2,4-dione, 2,2,6,6-tetramethyl-heptane-3,5-dione, 1-phenyl-butane-1,3-dione, 1,3-diphenyl-propane-1,3-dione, 1,1,1-trifluoro-pentane-2,4-dione, 1,1,1-trifluoro-hept-6-yne-2,4-dione, 1,1,1,5,5,5-hexafluoro-pentane-2,4-dione, 1,1,1,5,5,6,6,6-octafluoro-hexane-2,4-dione or 4,4,4-trifluoro-1-phenyl-butane-1,3-dione; and    Y3 = 4,4,4-trifluoro-1-(4-fluoro-phenyl)-butane-1,3-dione, 1-(4-chloro-phenyl)-4,4,4-trifluoro-butane-1,3-dione, 4-(4,4,4-trifluoro-3-oxo-butyryl)-benzonitrile, 4,4,4-trifluoro-1-(4-trifluoromethyl-phenyl)-butane-1,3-dione, 4,4,4-trifluoro-1-(4-nitro-phenyl)- butane-1,3-dione, 4,4,4-trifluoro-1-(4-methyl-phenyl)-butane-1,3-dione, 4,4,5,5,5-pentafluoro-1-(4-fluoro-phenyl)-pentane-1,3-dione, 1-(4-chloro-phenyl)-4,4,5,5,5-pentafluoro-pentane-1,3-dione, 4-(4,4,5,5,5-pentafluoro-3-oxo-pentanoyl)-benzonitrile, 4-(2,4,4,4-tetrafluoro-3-oxo-butyryl)-benzonitrile, 2,4,4,4-tetrafluoro-1-(4-fluoro-phenyl)-butane-1,3-dione, 1-(4-chloro-phenyl)-2,4,4,4-tetrafluoro-butane-1,3-dione, 2,4,4,4-tetrafluoro-1-(4-trifluoromethyl-phenyl)-butane-1,3-dione, 2,4,4,4-tetrafluoro-1-p-tolyl-butane-1,3-dione, 4,4,4-trifluoro-1-phenyl-butane-1,3-dione, 4,4,5,5,5-pentafluoro-1-phenyl-pentane-1,3-dione or 4,4,5,5,5-pentafluoro-1-p-tolyl-pentane-1,3-dione.    SPECIFIC COMPOUNDS - 29 Compounds (A) are disclosed e.g. ruthenium (4,4'-dicarboxy-4"-nonadecyl-2,2':6',2''-terpyridine)(1,1,1-trifluoropentane-2,4-dionato)(thiocyanato)(tetrabutylammonium), ruthenium (4,4'-dicarboxy-4"-nonadecyl-2,2':6',2''-terpyridine)(4,4,4-trifluoro-1-(4-fluorophenyl)butane-1,3-dione)(thiocyanato)(tetrabutylammonium), and ruthenium complexes of formulae (Aa)-(Ac).    EXAMPLE - 1,1,1-Trifluoropentane-2,4-dione (236 mu l) and triethylamine (0.5 ml) was added to a solution of the complex ruthenium (4,4'-diethoxycarbonyl-4"-nonadecyl-2,2':6',2''-terpyridine)trichloride (300 mg) in methanol (100 ml). The reaction mixture was refluxed for 8 hours and the solvent was then allowed to evaporate on a rotary evaporator. The solid mass thus obtained was dissolved in dimethylformamide (30 ml) under nitrogen. An aqueous solution (5 ml) of sodium thiocyanate (300 mg) was added to this solution. After being refluxed for 8 hours, triethylamine (10 ml) was added, and the solution was refluxed for further 24 hours. The reaction mixture was allowed to cool, and the solvent was removed on a rotary evaporator. The resulting solid was dissolved in 0.1 M aqueous sodium hydroxide and ruthenium (4,4'-dicarboxy-4"-nonadecyl-2,2':6',2''-terpyridine)(1,1,1-trifluoropentane-2,4-dionato)(thiocyanato) was precipitated by the addition of 0.1 M nitric acid. The resulting precipitate was filtered and dried. The isolated solid was recrystallized from methanol-diethyl ether, after which it was further purified. Powder ruthenium (4,4'-dicarboxy-4"-nonadecyl-2,2':6',2''-terpyridine)(1,1,1-trifluoropentane-2,4-dionato)(thiocyanato) was dissolved in 0.1 M aqueous tetrabutylammonium hydroxide and the mixture heated to 110 degrees C for 4 hours (the pH of the solution was about 11). The resulting purple solution was filtered to remove a small amount of insoluble material and the pH was adjusted to 5 with dilute hydrochloric acid. After allowing to cool to (25 degrees C) room temperature, it was filtered through a sintered glass crucible and dried under vacuum to give ruthenium (4,4'-dicarboxy-4"-nonadecyl-2,2':6',2''-terpyridine)(1,1,1-trifluoropentane-2,4-dionato)(thiocyanato)(tetrabutylammonium).