optimum temperature for the synthesis of tannic acid-metal complexes can vary depending on the specific metal and reaction conditions. Generally, room temperature or slightly elevated temperatures are common for these syntheses. Experimental conditions and desired outcomes can influence the choice of temperature, so it's advisable to refer to specific literature or experimental protocols for the metal complex you are interested in.

The optimum temperature for synthesizing tannic acid-metal complexes can vary based on specific conditions and metals involved. Generally, temperatures between 40-60°C are common for such syntheses.