TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The metal complex has structure of formula (II).M = transition metal atom chosen from ruthenium, osmium, iron, cobalt and copper; andLL1 = compound chosen from formulae (III-1) to (III-5).R11-R20 = carboxyl, hydroxyl, sulfonic acid group, phosphonic acid group, phosphoric acid group, silicic acid group, boric acid group or their proton dissociation components;R21-R30 = substituent which couples R11-R30 at any position on ring;c1-c9,c11-c19 = 0-4; andc10,c20 = 2 or more.Preferred Material: The optoelectronic transducer contains electrode to which semiconductor microparticles are coupled and/or adsorbed to the optoelectronic transducer material. Preferred Definitions:    R1-R4 = (un)substituted aryl, preferably a group of formula (V).    R31 = as R7; and    a3 = 0-5.    EXAMPLE - Tetrakis (dimethyl sulfoxide) ruthenium dichloride RuCl2(DMSO)4 (in g) (5), 4,4'-dicarboxy-2,2'-bipyridine (2.2), chloroform (100 ml) and ethanol (100 ml) were mixed in argon atmosphere. The mixture was refluxed for 6 days and stirred. Ethanol and chloroform were distilled after cooling to room temperature, and mixed solvent of acetone and ether was added to the residue. The obtained powder was filtered, and complex (A-7) was obtained. (A-7) (1.8) was mixed with bipyridyl type compound (A-4) (2.1) and dehydrated N,N-dimethyl formamide (100 ml). The mixture was stirred at 100 degrees C for 10 hours in argon atmosphere, and the obtained solution was evaporated under reduced pressure. The residue was recrystallized using mixed solvent of methanol and diethyl ether, and metal complex (6-1) was obtained.    R = -C6H5-COOH.    Semiconductor microparticles electrode substrate provided with substrate, conductive layer and semiconductor layer was immersed into ethanol solution of (6-1) for 15 hours. Subsequently, the substrate was removed and immersed into an acetonitrile solution of 4-t-butyl pyridine, and washed with ethanol. Platinum vapor-deposited glass was laminated on electrode substrate, and optoelectronic transducer was obtained. The transducer had excellent photoelectric current value and durability.