Laser-ablated Cu, Ag, and Au atoms react with H2O2 and with H-2 + O-2 molecules during condensation in excess argon to give four new IR absorptions in each system (O-H stretch, M-O-H bend, O-M-O stretch, and M-O-H deformation modes) that are due to the coinage metal M(OH)(2) dihydroxide molecules. Isotopic substitution (D2O2, O-18(2), (OO)-O-16-O-18, D-2, and HD) and comparison with frequencies computed by DFT verify these assignments. The calculations converge to (2)Bg ground electronic state structures with C-2h symmetry, 111-117 degrees M-O-H bond angles, and substantial covalent character for these new metal dihydroxide molecules, particularly for Au(OH)(2). This is probably due to the high electron affinity of gold owing to the effect of relativity.