Cobalt(II) clathrochelates as components of initiating systems for radical polymerization of methyl methacrylate

Abstract

200 The use of metal complex compounds in radical polymerization of vinyl monomers is one of the most successful and promising ways of development of tai lor made synthesis of polymers on their basis [1, 2]. It has been shown [3–6] that iron(II) semi and clathro chelates in combination with traditional initiators of radical polymerization (in particular, diacyl perox ides) form high performance initiating systems. Such systems have a favorable effect on both the kinetic parameters of the process (increase the initiation rate; under certain conditions, mitigate the detrimental gel effect; reduce the effective activation energy of poly merization; etc.) and the physicochemical character istics of the resulting polymers (variation of the molec ular weight from 300 thousand daltons to 4 million daltons, the increase in stereoregularity and thermal stability). In this context, the use of new types of clath rochelates, in particular, macrobicyclic cobalt(II) tris(α dioximate)s (Scheme 1, compounds 1–3), as modifying additives in the radical polymerization of methyl methacrylate (MMA) initiated by benzoyl per oxide seems to be promising. All these compounds dif fer from the previously studied cage iron(II) com plexes [3–6] in the nature of both the encapsulated metal ion and the apical and edge substituents.