The metal nature effects in cryopolymerized metalated poly- p -xylylene

Metal‐Containing Polymers: Cryochemical Synthesis, Structure, and Physicochemical Properties

“…Thus, the bonds in complexes of PX with a magnesium atom (or cluster Mg n ) are neither purely ionic not covalent, but have intermediate structure. This was confirmed by quantum chemical calculations [36]. Polymerization under UV radiation at 77 K is accompanied by the shift of band from 340 to 310 nm (Figure 2.3), which means the transformation of initial complexes into organomagnesium units of PPX backbone chains [-CH 2 -C 6 H 4 -CH 2 -Mg n -] with Mg-C bonds [35,36] close to s bonds of organomagnesium compounds.…”

“…This was confirmed by quantum chemical calculations [36]. Polymerization under UV radiation at 77 K is accompanied by the shift of band from 340 to 310 nm (Figure 2.3), which means the transformation of initial complexes into organomagnesium units of PPX backbone chains [-CH 2 -C 6 H 4 -CH 2 -Mg n -] with Mg-C bonds [35,36] close to s bonds of organomagnesium compounds. The fact that the absorbance maximum of Mg-C bonds in Mg-PPX is at 310 nm and not in the range 270-300 nm indicates some deformation of these bonds as compared to those of usual stable organomagnesium compounds.…”

“…In the UV-Vis spectrum of this co-condensate, there is a very intense band with maximum close to 340 nm (Figure 2.3) [36]. This band lies between absorption bands of ionic organometallic compounds in the range 420-470 nm and those of organomagnesium derivatives with predominantly covalent Mg-C bonds in the range 280-300 nm [38,39].…”

“…In the spectrum of Mg-PPX annealed in vacuum at room temperature along with polymeric band, there are two new weak bands at 345 and 440 nm (Figure 2.3) that suggest the formation of Mg 3 clusters. Other Mg clusters, which probably form from organomagnesium structures, could not be observed on a background of PPX absorption [36]. In air at room temperature, organomagnesium structures and Mg clusters oxidize with the formation of MgO nanocrystals of mean size about 35 Å immobilized in PPX matrix [36].…”

“…The structure and polymerization of the vapor-deposited PX-Mg monomer system were described in references 23 and 34-37. Taking into consideration IR and UV-Vis spectral data, it was concluded that the co-condensation of Mg with PX at 77 does not lead to the PX polymerization but results in formation of charge transfer complexes where PX is in the benzenoid form [35,36] (Scheme 2.4).…”