Supramolecular stabilization oligomers

Supramolecular stabilization means stabilization of certain chemical species, their different forms, and assemblies in a particular supramolecular environment. Supramolecular stabilization is responsible for the existence of "energetically unfavorable" conformations, different spatial isomers, unexpected oligomers, "unstable" molecules. highly reactive radicals, elements in unusual oxidation states, certain ionic species, and so on, in supramolecular phases. Such species decompose, change, or equilibrate with alternative forms once they are brought out of their "stabilizing" environment. The best-known chemical reaction based strictly on supramolecular stabilization is the so-called "blue reaction." where iodine reversibly polymerizes in the presence of starch. 

Silanetriols represent versatile building blocks for the construction of polyhedral metallasiloxanes. To transform such oligomers into supramolecular structures special efforts are directed towards the preparation of stable silanetriols bearing hydrolyzable functionalities. Stabilization of silanetriols with respect to self-condensation can be achieved by steric and electronic shielding of the Si atom. Our approach to this topic is the application of cyclopentadienyl (Cp) ligands (see Fig. 1). 

The analysis of the oligomer supramolecular structure as well as the analysis of any other level of any system structure (see Part 1.3) has to consider three factors geometric (mutual arrangement of the system elements in the environment), thermodynamic (the stability of the system and minimization of free energy), and kinetie (the time of relaxation to equilibrium and the life cycle of a structural element) [76]. 

Therefore, the spontaneous formation of the equilibrium supramolecular system structure, which provides its kinetic curing stability, and does not depend on the prehistory of the sample, occurs after the completion of swelling, within the exposure period 0contact with the liquid phase. During this period, local molecule concentration redistribution and spontaneous supramolecular structure elements formation (cybotactic groupings and associates) occur in the macroscopic sample volume. The characteristics of these elements (lifetime, correlation radius, strength of physical bonds) differ from the similar indices or coefficients in the initial oligomer and in the polymer-oligomer film, which is in contact with liquid. 

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