Pentacarbonylhydridorhenium is a chemical compound with the formula ReH(CO)<sub>5</sub>. This colorless liquid is a weak acid and represents one of the most important derivatives of dirhenium decacarbonyl (Re<sub>2</sub>(CO)<sub>10</sub>). It is synthesized by treating a methanolic solution of bromopentacarbonylrhenium(I) (Re(CO)<sub>5</sub>Br) with zinc and acetic acid (HOAc).
It is moderately sensitive to light: samples turn yellow due to the formation of the metal cluster Re<sub>3</sub>H(CO)<sub>14</sub>
At 100 ðC, it decomposes to Re<sub>2</sub>(CO)<sub>10</sub>: