TECHNOLOGY FOCUS - POLYMERS - Preferred Compound: The polynuclear metal complex having chromic near-infrared absorption characteristics is of formula: M1M2M3(( mu )3-X)(( mu )-RCOO)6(L1L2L3) (1).M1-M3=metal ions of group 4-13 having complexing ability, preferably titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, zinc, gallium, or palladium;X=oxo ion (O2-) or nitride ion (N3-);R=H, alkyl or monovalent aromatic group;L1-L3=ligands chosen from heterocyclic compound having conjugated double bond or its derivative(s), carbonyl (CO), isonitrile (R1NC), nitrosyl (NO), phosphine (PR2)3, ammine (NH3), aqua (H2O), hydroxo (OH-) and cyano (CN-);andR1,R2=alkyl or monovalent aromatic group.At least one of L1-L3 is nitrogen heterocyclic compound or its derivative(s), preferably pyridine type derivative having functional group, chosen from pyridine, methyl bipyridine, cyano pyridine, and dimethylamino pyridine. Preferred Components: The transparent organic polymer is chosen from vinyl polymer, (meth)acrylic-type polymer, polycarbonate-type polymer, polyarylate-type polymer, polyester-type polymer and olefin polymer, preferably vinyl alcohol type polymer and (meth)acrylic-type polymer, more preferably vinyl alcohol type polymer. Preferred Composition: The content of polynuclear metal complex having chromic near-infrared absorption characteristics with respect to 100 mass parts of transparent organic polymer in organic polymer composition is 0.01-50 mass parts. EXAMPLE - Ruthenium chloride n-hydrate (in g) (1) and sodium acetate (2) were dissolved in mixed solvent of ethanol (25 mL) and acetic acid (25 mL), refluxed for 6 hours, cooled to room temperature, sodium acetate was precipitated and removed by filtration, evaporated solution portion to dryness and dissolved the residue in methanol (100 mL), re-evaporated to dryness and precipitated, to obtain blue-green solid. The obtained blue-green solid (500 mg) was dissolved in methanol (20 mL), 1-methyl-4,4'-bipyridinium hexafluoro-phosphate salt (700 mg) was added, refluxed for 1 hour and crystallized, to obtain polynuclear metal complex. Polyvinyl alcohol (in mass parts) (100) was dissolved in water, to obtain polyvinyl alcohol aqueous solution. Then, polynuclear metal complex (1) was added to the aqueous solution and stirred, to obtain polyvinyl alcohol composition. The obtained composition was flow-spread on 60 degrees C-hotplate and dried at 60 degrees C, to obtain polyvinyl alcohol film. The obtained film had excellent external appearance.