Аннотация:The structure of the nuclei from 9Li-9Be to 11Li-11Be at sequential neutron addition was studied within the framework of the shell model with an extended basis taking into account the competitive of jj- coupling and Majorana exchange forces. Their wave functions (WF) were defined. The formalism of calculation of spectroscopic factors of a dineutron and separate neutrons in nuclei with WF including of the shell configurations mixing is explained. 9Li(t, p) 11Li and 9Ве(t, p)11Ве reactions taking into account mechanisms of a dineutron stripping and consecutive neutron transfer are considered as the indicator of the offered structure of lithium and a beryllium isotopes. Parameters of optical potentials, bound state wave functions of the transferred particles and the interaction potentials corresponding to them are determined from comparison of theoretical angular distribution of protons from 9Ве(t, p)11Ве reaction with the experimental one. It is shown that dineutron periphery with 6.4 Fm size takes place at 11Li nucleus and one-neutron periphery with 8 Fm size takes place at 11Ве.