Quasimolecular dipole transition moments have been considered analytically within the framework of the two-state approximation. In the process, the conditions that lead to the occurrence of roots (zeros) for the dipole moments have been carefully studied. The underlying reason for these roots is the orthogonality of the quasimolecular adiabatic states. In the second part of the theory specific attention is given to spectral manifestations connected with dipole moment peculiarities. Among the main enhanced results, it was found that the existence of a root in the vicinity of the extremum of the potential energy curve produces a dip in the spectral profile rather than a satellite as usually supposed. Our work allows an obvious advance in the theory of radiative collisions and the study of the influence of the interaction in quasimolecules.