TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No general preparation given. Preferred Definitions:    R1,R3=cyano;    R2,R4=carboxy;and    M=ruthenium.    SPECIFIC COMPOUNDS - 39 Dyes e.g. 4',12'-bis((5-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)thiophen-2-yl))-8,8-diisothiocyanato-7,7',9,9'-tetraaza-8-ruthena-8,8'-spirobi(tricyclo(7.4.0.02,7)tridecane)-1(9),1'(9'),2(7),2'(7'),3,3',5,5',10,10',12,12'-dodecaene-4,12-dicarboxylic acid, 4'-(5-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)thiophen-2-yl)-12'-(5-(5-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)thiophen-2-yl)thiophen-2-yl)-8,8-diisothiocyanato-7,7',9,9'-tetraaza-8-ruthena-8,8'-spirobi(tricyclo(7.4.0.02,7)tridecane)-1(9),1'(9'),2(7),2'(7'),3,3',5,5',10,10',12,12'-dodecaene-4,12-dicarboxylic acid, 4'-(5-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)thiophen-2-yl)-12'-(5-(5-(5-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)thiophen-2-yl)thiophen-2-yl)thiophen-2-yl)-8,8-diisothiocyanato-7,7',9,9'-tetraaza-8-ruthena-8,8'-spirobi(tricyclo(7.4.0.02,7)tridecane)-1(9),1'(9'),2(7),2'(7'),3,3',5,5',10,10',12,12'-dodecaene-4,12-dicarboxylic acid, 4',12'-bis((10-((1E)-2-carboxy-2-cyanoeth-1-en-1-yl)-3,7,11-trithiatricyclo(6.3.0.02,6)undeca-1(8),2(6),4,9-tetraen-4-yl))-8,8-diisothiocyanato-7,7',9,9'-tetraaza-8-ruthena-8,8'-spirobi(tricyclo(7.4.0.02,7)tridecane)-1(9),1'(9'),2(7),2'(7'),3,3',5,5',10,10',12,12'-dodecaene-4,12-dicarboxylic acid or 12'-(5-(2-carboxy-2-cyanoethyl)thieno(3,2-b)thiophen-2-yl)-4'-(5-((1E)-2-carboxy-2-methyleth-1-en-1-yl)thieno(3,2-b)thiophen-2-yl)-8,8-diisothiocyanato-7,7',9,9'-tetraaza-8-ruthena-8,8'-spirobi(tricyclo(7.4.0.02,7)tridecane)-1(9),1'(9'),2(7),2'(7'),3,3',5,5',10,10',12,12'-dodecaene-4,12-dicarboxylic acid, are disclosed.    EXAMPLE - (2E)-3-(5-(4'-(4-((E)-2-carboxy-2-cyanovinyl)thien-2-yl)-2,2'-bipyridin-4-yl)thien-2-yl)-2-cyanoacrylic acid (2.04 g), ruthenium chloride (0.52 g) and N,N-dimethylformamide (50 ml) were mixed, stirred and heat-refluxed for 3 hours. The mixture was cooled to room temperature, and solvent was removed under reduced pressure. Hydrochloric acid was added and stirred at room temperature for 2 hours to produce dye at yield of 83.6%. The obtained dye was mixed with potassium thiocyanate aqueous solution (4.95 g), stirred, heat-refluxed and cooled to produce sensitizing dye.