Abstract
<title>Abstract</title> <p> Proton-coupled charge transfer (PCCT), a fundamental principle underlying biological electron transport, has rarely been realized in crystalline materials, where the charge, proton, and spin degrees of freedom can be cooperatively controlled. Herein, we report a redox-active layered donor (D)–acceptor (A) metal-organic framework (D <sub>2</sub> A-MOF), in which modulation of the intramolecular hydrogen bonds (HBs) acts as a decisive trigger for intralattice charge transfer and a concomitant magnetic phase transformation. The framework is constructed from an <italic>o</italic> -hydroxybenzoate-bridged paddlewheel-type diruthenium(II,II) complex as the D unit and bis[1,2,5]dithiazolotetracyanoquinodimethane (BTDA-TCNQ) as the A unit. Systematic solvent desorption selectively disrupts the intramolecular HB between the <italic>o</italic> -hydroxy group and the carboxylate oxygen, effectively converting the D unit into a D* state at a higher potential. This HB-mediated electronic reorganization induces a one-electron transfer from [Ru <sub>2</sub> ] to BTDA-TCNQ, generating a [–{Ru <sub>2</sub> } <sup>+</sup> –(BTDA-TCNQ) <sup>•–</sup> –{Ru <sub>2</sub> } <sup>0</sup> –] state that converts the material from a paramagnet to an antiferromagnet with a Néel temperature of 58 K. Density functional theory (DFT) calculations corroborate the decisive role of HB mode switching in tuning the highest occupied molecular orbital (HOMO) level of the donor and enabling charge transfer. This study establishes modulation of intramolecular HBs as a powerful design principle for PCCT in MOFs and demonstrates a chemically triggered magnetic phase transition driven by guest-controlled proton dynamics. </p>