Solid-state cocondensation

Heterochain polymers of the type -(M-X) - contain polar M-X bonds (for reviews see [1,2,12-15]). Such polymers are often prepared by polycondensation of a bifimctional metal halide (M = B, Si, Ge, Sn, Pb, Sb, Ni, Pd, Pt, Ti, Hf) with a bifunctional Lewis base such as a diol, diamine, dihydrazine, dihydrazide, dioxime, diamideoxime, dithiol, diacetylene (Eq. 7-2). Another possibilitiy is the polyaddition of a bifunctional metal hydride to bifunctional alkenes (Eq. 7-3). Mn and mg containing poly(p-xylylenes) of the composition -(-CH2-C6H4-CH2-M-) - were produced by solid-state UV-photopolymerization of a cocondensated mixture of p-xylylene with Mn or mg at 80 K [16]. Prolonged storage of the polymers at ambient temperature under vacuum led to gradual decomposition. 

Inorganic nanoparticles such as metal/semiconductors (M/SC) immobilized in polymer matrices have attracted considerable interest in recent years due to their distinct individualistic and cooperative properties [84]. Although the control of size and shape of M/SC nanoparticles has been widely investigated, the fundamental mechanism of nanostructural formation and evolution is still poorly understood. A novel cryochemical solid-state synthesis technique has been developed to produce M/SC nanocomposites [85]. This method is based on the low-temperature cocondensation of M/SC and monomer vapors, followed by the low-temperature solid-state polymerization of the cocondensates. As a result of the method of stabilizing the metal particle without requiring any specific coordination bonds between the particle surface and the polymer matrix, generated nanoparticles (Ag-nanocrystal mean size 50 A) were embedded in the polymer matrix with well-controlled shapes and a narrow size distribution [86]. 

Complexes between some lanthanides in a low oxidation state and olefins were isolated by W.J. Evans et al. (1978a, 1981b). Cocondensation of lanthanum, neodymium, samarium or erbium metal with butadiene or 2,3-dimethylbutadiene at — 196°C in a metal vaporization reactor produces a brown solid, which can be extracted by toluene and tetrahydrofuran yielding soluble brown products with the empirical formulas R(C4H4)j for R = Nd, Sm, Er, and R[(CH3)2C4H4]2 for R = La, Er. For these complexes the following three formulas have been suggested ... 

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