Modeling the allosteric effect: modification of the tautomerism by intermolecular interactions and extension to molecular wires
B3LYP/6−31G(d) and B3LYP/6−311++G(d,p) calculations were carried out on quinolone and its four azaderivatives (15 tautomers), five wire models (10 tautomers) for proton transfer formed of anthracenol and azaacridines and the corresponding five crown ethers (ten tautomers) in the anthracenol part. The wires are formed by four carbon atoms existing either as cumulenes (pentaene) or polyynes (diyne). On these structures the effect of hydrogen bonds with HF as hydrogen bond donor, protonation on the aza N atoms and coordination with Li+ on the same positions were studied. The resulting energies were analyzed taking into account proximity effects.