Metallosiloxane MnM’m[RSiO1.5]n and metallogermoxane MnM’m[RGeO1.5]n cluster units (M = transition metal, i.e. Cu, Co, Ni, Fe, M’ – alkali metal, i.e. Na, K, Cs, Rb, n = 2-7, m = 2 - 10) are relatively rigid polynuclear nanosized units possessing catalytic [1] and magnetic [2] properties. The shape and size of cluster units generally governed by the nature of transition metal and synthetic conditions, while the nature of alkali metal and solvent affect connectivity of these cages [3]. Rigidity of cages is responsible for realization of supramolecular and coordination architectures with open channels and voids up to 15 Å. Moreover, as coordination polymers are formed by M-O and M’-O interactions only, these porous architectures remain stable up to 400°C when the organic coating is decomposed [3a].
In this study we discuss the effect of M, M’ and E (E = Si, Ge) nature on the shape and connectivity of cluster units, the topology and abundance of 1D, 2D and 3D architectures based on organometallosiloxanes and germoxanes, and synthetic pathways to form porous 2D and 3D nets. Multitemperature PXRD data of various compounds are compared to investigate thermal stability of the title compounds and their ability to form purely inorganic molecular sieves. The latter can be used for catalysis and gas sorption.
The work was supported by the Russian Foundation for Basic Research (projects 16-29-05180 and 16-03-00206).