07-27U

The possibility of the first- or the second-order transitions from uniform phase into phase with doubled lattice period in the quasi-one-dimensional structures with hydrogen bonds is studied in framework of proposed pseudospin-electron model. The dependence of the electron concentration and mean number of protons on site on temperature and asymmetry field were obtained. It was shown, that abruptly changes of this characteristics at the first- -order transitions is smaller for the structures with high proton tunnelling frequency. The equation for the second-order phase transition temperature is obtained. The electron spectrum is calculated. The dependence of the splitting of the electron spectrum and dependence of the electron conductivity on temperature and asymmetry field is investigated.