In an effort to probe the feasibility of a model of Mo-Cu CODH (CODH = carbon monoxide dehydrogenase) lacking a bridging sulfido group, the new heterodinucleating ligand LH 2 was designed and its Cu(I)/Mo(VI) reactivity was investigated. LH 2 ((E)-3-(((5-(bis(pyridin-2-ylmethyl)amino)-2,7-di-tert-butyl-9,9-dimethyl-9H-xanthen-4-yl)imino)methyl)benzene-1,2-diol) features two different chelating positions bridged by a xanthene linker: bis(pyridyl)amine for Cu(I) and catecholate for Mo(VI). LH 2 was synthesized via the initial protection of one of the amine positions, followed by two consecutive alkylations of the second position, deprotection, and condensation to attach the catechol functionality. LH 2 was found to exhibit dynamic cooperativity between two reactive sites mediated by H-bonding of the catechol protons. In the free ligand, catechol protons exhibit H-bonding with imine (intramolecular) and with pyridine (intermolecular in the solid state). The reaction of LH 2 with [Cu-(NCMe) 4 ] + led to the tetradentate coordination of Cu(I) via all nitrogen donors of the ligand, including the imine. Cu(I) complexes were characterized by multinuclear NMR spectroscopy, high-resolution mass spectrometry (HRMS), X-ray crystallography, and DFT calculations. Cu(I) coordination to the imine disrupted H-bonding and caused rotation away from the catechol arm. The reaction of the Cu(I) complex [Cu(LH 2 )] + with a variety of monodentate ligands X (PPh 3 , Cl − , SCN − , CN − ) released the metal from coordination to the imine, thereby restoring imine H-bonding with the catechol proton. The second catechol proton engages in H-bonding with Cu−X (X = Cl, CN, SCN), which can be intermolecular (XRD) or intramolecular (DFT). The reaction of LH 2 with molybdate [MoO 4 ] 2− led to incorporation of [Mo VI O 3 ] at the catecholate position, producing [MoO 3 (L)] 2− . Similarly, the reaction of [Cu(LH 2 )] + with [MoO 4 ] 2− formed the heterodinuclear complex [CuMoO 3 (L)] − . Both complexes were characterized by multinuclear NMR, UV−vis, and HRMS. HRMS in both cases confirmed the constitution of the complexes, containing molecular ions with the expected isotopic distribution.