The Chemistry of p-Xylylene.¹ I. The Preparation of Solutions of Pseudodiradicals²

Poly(p-xylylene) and Its Derivatives by Chemical Vapor Deposition: Synthesis, Mechanism, and Structure

“…FT-IR spectra were recorded by a Perkin-Elmer type 1600 FT-IR spectrometer. 13 C cross magic angle spinning (CP-MAS) NMR spectra were obtained with a Bruker MSL 300 spectrometer at a 13 C resonance frequency of 75.47 MHz and a rotor frequency of about 3 kHz. Total suppression of sidebands (TOSS) was achieved by a pulse sequence introduced following ref 10.…”

Experimental consideration of covalent‐bonding interactions in stacks of singlet biradicals having Kekulé structures

“…The former is concluded to be a polyenic species by using 1 H-NMR, electron spin resonance (ESR), [21] UV-Vis, [22] and photoelectron measurements, [23] whereas its high chemical reactivity to give dimeric and polymeric compounds would suggest the potential singlet biradical character. [24][25][26] For the latter compound, a molecular geometry is determined by X-ray crystallography, and the comparison of the geometry with a smaller homolog (Thiele's hydrocarbon) suggests large singlet biradical character, [27] but its high reactivity makes physicochemical measurements difficult, and the definitive electronic structure, especially the extent of an intramolecular spin-spin interaction, is still open for discussions. [28] In this way, stability is a very important factor for exploring the feature of Kekulé singlet biradicals and would be inevitable for the application in electronics and spintronics devices.…”

Polymerization behavior of 2,5-bis(dicyanomethylene)- 2,5-dihydrofuran

“…However, it is so reactive that, when prepared, it polymerizes spontaneously even at Ϫ78 o C and cannot be isolated in a pure state as crystals. [1][2][3] Replacement of the hydrogen atoms on the exocyclic methylenes at the 7-and 8-positions in the QM with electron-donating substituents such as phenyl and alkylthio groups and/or electron-accepting ones such as cyano, acyl, and alkoxycarbonyl groups lowers the reactivity of the QM, and therefore, the substituted QMs are obtainable as isolable crystals at room temperature. 4 -7 As the substituted QMs are more stable, treatable, and highly conjugative monomers compared to ethylenes, they are expected to exhibit novel polymerization behavior beyond the scope of conventional polymer chemistry established on the basis of vinyl polymerizations of ethylenes.…”