The mechanism of occurrence of cooperative properties in conjugate hydrogen bonds

The literature data on the change of v(HX) frequencies in hydrogen-bonded complexes of different structure are analysed. It is shown that the earlier found frequency dependencies can have a simple physical explanation. It consists in the fact that the XH-bond of any molecule, apart from its proton-donor and proton-acceptor properties, also has certain transmission abilities. It means that when hydrogen bonds are conjugated, to the proton-donor ability of any XH-group is always added a certain part (specific for this XH-group) of the proton-donor ability of the molecule, in relation to which this XH-group acts as a proton-acceptor. Similarly, the proton-acceptor property of XH-group is increased by a certain part (specific for this XH-group) of the proton-acceptor ability of the molecule, in relation to which this XH-group acts as the proton-donor. The dependence of the proton-donor (proton-acceptor) ability on the bend of the angle adjacent to the hydrogen bond is found.