Hydrogen–deuterium exchange of the carbon-bound C(8)-H protons of the inosine residues in tetrakis(inosine)platinum(II) chloride, S, with Pt binding at N(7), was studied in aqueous buffer solutions at 60 °C by 1H NMR spectroscopy. The kinetics at all four C(8) sites as a function of pD of the D2O/OD− medium was measured through the disappearance of the C(8)-H signal, which yielded the pseudo first-order rate constant for exchange, kobs. Plots of kobsversus [OD−] showed curvature reminiscent of saturation type kinetics and indicative of competitive deprotonation of N(1)-H sites. In contrast, the analogous N(1)-methylated cis-bis(1-methylinosine)diammineplatinum(II) chloride leads to a linear kobsversus [OD−] plot. The potentiometrically determined macroscopic composite N(1)-H ionization constant was further dissected into the successive microscopic N(1)-H acidity constants of the four inosine residues of the complex S. The kobs values were also deconvoluted into individual rate constants kex (i.e.k0, k1, k2, k3 for exchange of the successively deprotonated inosine moieties, S, S1, S2, S3, it being assumed that S4 where all four inosine ligands are deprotonated at N(1) is unreactive (“immunized”) to exchange. The kex values show a progressive attenuation in Pt activation of H–D exchange along the series, k0, k1, k2, k3. The kex data thus generated, together with the deconvoluted individual pKa values allow the construction of the plot, log kex [C(8)-H] vs. pKa [N(H)-1]. Remarkably, this plot exhibits good linearity (R2 = 0.99), which accords this as a linear free energy relationship (LFER). The large negative slope value (−2.3) of this LFER reflects the high sensitivity of transmission of electron density from the ionized N(1)viaPt and/or through space to the remaining C(8)-H sites. This is to our knowledge the first instance in which a LFER is generated through modulation of a structure in a single molecule. One can anticipate that this approach may lead to: (1) predicting N-H acidity; (2) C-H H–D exchange susceptibility in a range of metal–biomolecule complexes; (3) their carbon acidity.