Used as a catalyst in various organic reactions, particularly in coupling reactions such as the Ullmann reaction, where it facilitates the formation of carbon-carbon bonds. Commonly employed in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals. Acts as a reagent in the Sandmeyer reaction to prepare aryl halides from diazonium salts. Utilized in electroless copper plating processes for printed circuit boards due to its ability to reduce and deposit metallic copper. Also found in some wood preservatives and antifouling paints, where it inhibits microbial and algal growth. Plays a role in gas sensing technologies, especially for detecting carbon monoxide. Used in photochemical processes and in the development of luminescent materials.