Silicon dioxide is most commonly encountered and widely used compound which finds various uses, from material technologies to microelectronics and fiber optics. The bulk and surface properties of SiO2 are controlled by the defect and impurity structures of the material. Silica surface can be activated by different methods (mechanical treatment, thermochemical treatment) with formation of various defects [1,2]. Despite different methods of silica activation, intrinsic defects of two main types in which the silicon atom is bound to three (paramagnetic) or two (diamagnetic) lattice oxygen atoms are stabilized on its surface. Point defects stabilized on the activated silica surface are highly reactive and can be used to design of both paramagnetic and diamagnetic intermediates grafted onto the surface. Molecules from the gas phase serve as building blocks. Thus, the involvement of the surface defects in reactions with different molecules provides a way for the initial centers to be purposefully modified by incorporating certain functional groupings in their composition and thereby to ultimative arrive at the desired structures. Taking into account the specific feature of quartz glass and the directness of a siloxane bond we may assume that defects of the same type can be stabilized and in the bulk of silica.

This method is efficient in preparing various intermediates. This technique is presently used to produce more than 100 different reactive structures containing silicon, carbon, nitrogen, germanium, sulphur and other elements. Using this method enabled us to collect information about spectral characteristics of these groups and the directions and reactivities of thermal, chemical and photochemical processes with their participation. The results of these studies are presented in this communication.

1. V.A.Radtsig, Chem. Phys. Reports, 1995, Vol. 14(8), pp.1206-1245.
2. V.A.Radzig, Kinetics and Catalysis, Vol.40, No.5, 1999, pp.693-715.