A silicon-containing polyazomethine and derived metal complexes: synthesis, characterization, and evaluation of the properties

Abstract

A new dialdehyde-containing silicon was prepared by a reaction of Williamson-type and structurally characterized. By its subsequent condensation with 2,5-bis(p-aminophenyl)-1,3,4-oxadiazole, a multifunctional polyazomethine-containing imine, phenylene, oxadiazole, ether, and carbosilane groups within the chain was prepared. The complexes of this polymer with Co(II), Cu(II), and Zn(II) ions formed on the basis of electron-donor ability of the oxadiazole and azomethine groups were prepared in a one-step approach by mixing the two precursors of polyazomethine (dialdehyde and diamine) with corresponding metal salt. The ligand and metal complexes were characterized by spectral (Fourier transform infrared (FTIR), 1 H, and 13 C NMR) methods. The thermal, optical, electrochemical, and dielectric properties were studied and the effects of the metal insertion in dependence on its nature over these properties were evaluated. All compounds are soluble in common organic solvents and show low glass transitions due to the flexible ether and Si-C bonds, are fluorescent, mainly due to the oxadiazole ring, are redox active and have high dielectric constant due to the presence of oxadiazole, azomethine metal units.

New cardo silylated poly(azomethine)s containing 9,9′‐diphenylfluorene units as materials with Brønsted acid‐dependent fluorescence

“…This is probably due to the increase in polarity of the chains caused by the protonation of the imine groups, which would favor polymer–solvent interactions. This behavior of PAzMs has been reported with several Brønsted acids, Lewis acids and metals …”

“…These last two signals were also evidenced in the spectrum of PAzMC2. Both samples showed a signal in the Si NMR spectrum, whose chemical shift was in accordance with the magnetic environment of the silicon atom . For PAzMC1 which contains a PhSi(CH 3 ) 2 Ph moiety, the signal was evidenced at ca −8 ppm (Fig.…”

“…C NMR (CDCl 3 , δ , ppm): 64.91* (C14); 120.10 (C18); 120.82 (C11); 126.08 (C17); 126.58 (C3); 127.41 (C6); 127.68, 127.72 (C16, C19); 128.01 (C22); 128.95 (C12); 129.27 (C7); 129.79 (C24); 133.74*, 133.89* (C1, C21); 134.78 (C2); 135.38* (C8); 136.38 (C23); 140.02*, 140.13* (C4, C15); 143.73* (C5); 145.01* (C13); 150.56* (C10); 151.21* (C20); 159.47 (C9); 191.86 (CHO terminal aldehyde). Si NMR (CDCl 3 , δ , ppm): −13.25. Elemental analysis, calcd for (C 63 H 44 N 2 Si) n (857.18) n (%): C, 88.27; H, 5.51; N, 3.82; found (%): C, 87.21; H, 4.82; N, 3.00.…”

“…Cu(II), Zn(II)) through the nitrogen lone pair of the CN units, which acts as a basic center . These interactions also increase their solubility in organic solvents and modify their thermal stability …”

Metallopolymers based on a polyazomethine ligand containing rigid oxadiazole and flexible tetramethyldisiloxane units

“…Some time ago, we began to prepare different PAZs and derived metal complexes with at least a siloxane‐based component (either carbonyl or amine) . We recently reported the synthesis of new dialdehyde‐containing dimethyl silane units, bis(formyl‐ p ‐phenoxymethyl) dimethyl silane, and its use in the preparation of PAZs.…”