Bis(arene)chromium-containing polyacrylonitrile and its thermolysis products: synthesis, characterization and magnetic properties

Abstract

Polyacrylonitrile bonded to bis(arene)chromium complexes was prepared by the polycyanoethylation reaction between acrylonitrile and various bis(arene)chromium complexes. The star‐shaped molecules consisted of a central bis(arene)chromium species with up to four polyacrylonitrile arms (each composed of up to 63 acrylonitrile units) covalently bonded to the arene ligands. The products of thermolysis of the polymers at 160°C and 350°C were characterized by elemental analysis as well as infrared nuclear magnetic resonance, electron paramagnetic resonance, Mössbauer and X‐ray photoelectron spectroscopies. Thermolysis at 160°C resulted in essentially complete decomposition of the bis(arene)chromium complexes, the polyacrylonitrile chains remaining unaffected. At thermolysis temperatures above 300°C, cyanogen and ammonia were evolved, spectroscopic studies of the resulting material indicating formation of conjugated polynaphthyridine‐type products containing ketoimine fragments. The product of thermolysis at 160°C showed room temperature ferromagnetism and that obtained at 350°C was an antiferromagnet with a Neel temperature of ca. 150 K. Copyright © 1999 John Wiley & Sons, Ltd.

Novel vanadium‐containing polymers prepared from bis(arene)vanadium and acrylonitrile: third‐order non‐linear optical properties

“…Previously, we have found that the treatment of bis(arene)chromium with acrylonitrile gives rise to coordinative polymerization at (arene) 2 Cr 0 , the chain termination step being transfer of an aromatic proton with formation of a bond between the polyacrylonitrile chain and the arene ligand of the chromium complex 6. 7 Here we report that bis(arene)vanadium‐containing polyacrylonitrile can be synthesized in a similar fashion, and that its solutions exhibit outstandingly high third order non‐linear optical properties.…”

Organometallic self-organized nanomaterials for nonlinear optics

“…However, there is evidence for a very significant influence of the polymer matrix on the metal complex, a comparison of the 1 H NMR spectra for CrPAN and (arene) 2 Cr showing a very large shift to low field for the resonances of the aromatic protons (from 4.16 ppm to 7.1-7.5 ppm) (Fig. 3).…”

“…[1][2][3][4][5] The resulting star-shaped molecules consist of a central (arene) 2 M species with polyacrylonitrile arms covalently bonded to the arene ligands. The properties of thermolysed bis(arene)metal-containing polyacrylonitrile (MPAN) are consistent with the formation of conjugated ladder-type polynaphthyridine structures.…”

Polyacrylonitrile reinforced PVA based-polymeric networks: Structural, morphological, and mechanical aspects

“…These polymers are closely related to other multi‐component materials, containing completely entangled chains, such as polymer blends, grafts and blocks. Miscibility of the constituent components of the IPNs is a main factor in determining the IPN's morphology .…”