Protonmotieven

Protonmotieven is a term used in Dutch-language chemistry and biochemistry to refer to recurring structural patterns in which protons play a decisive role. The concept covers protonation and deprotonation motifs, hydrogen-bond networks that shuttle protons, and sequences of proton transfer steps within molecules or across membranes. In this sense, motifs are not fixed molecules but characteristic arrangements that recur in different contexts and influence properties such as acidity, reactivity, and transport.

Motifs can be categorized by their function or topology. Protonation/deprotonation motifs describe sites that gain or lose protons, determining acid-base behavior. Hydrogen-bond motifs describe networks that stabilize charged or neutral forms and can steer proton transfer. Proton-transfer motifs involve sequences of donor and acceptor groups that create low-energy pathways for protons, as seen in enzymes, buffers, and proton channels. In catalysis, proton-motif patterns help explain how active sites facilitate reactions by arranging protons at key positions. In membranes, proton pores and networks underlie the generation of electrochemical gradients.

Researchers identify proton motifs through structural databases, pKa calculations, hydrogen-bond analysis, and simulations (classical and quantum chemical). Experimental techniques such as infrared spectroscopy, NMR, and neutron diffraction can corroborate proton positions and transfer events. The concept is used to rationalize observations across disciplines, from enzymology to materials science, where proton behavior governs acidity, selectivity, and energy conversion.

Note that protonmotieven is a Dutch-language label for a broader idea of recurring proton-related patterns. While not always standardized in English-language literature, the concept aligns with established ideas of protonation chemistry, hydrogen-bond networks, and proton-coupled processes.