A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands (XpyMe)TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal-bound functionalities. To illustrate such H-bonding interactions, a series of [(XpyMe)TpCu](2)(mu-OH)(2) (6a-6e) complexes were synthesized from the corresponding (XpyMe)TpCu-OAc (5a-5e) complexes. Single crystal X-ray structures of three new dinuclear [(XpyMe)TpCu](2)(mu-OH)(2) complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric (DMAPME)TpCu-OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced nu(OH) frequencies that tracks with the H-bond accepting ability of the pendant arm. Reversible protonation studies that interconvert [(XpyMe)TpCu](2)(mu-OH)(2) and [(XpyMe)TpCu(OH2)]OTf species indicate that the acidity of the corresponding aquo ligand decreases with increasing H-bond accepting ability of the pendant arm.