344938-52-9Relevant articles and documents
Synthesis, structure, and properties of alkyl-substituted PPXs by chemical vapor deposition for stent coatings
Bier, Anna K.,Bognitzki, Michael,Mogk, Jochen,Greiner, Andreas
experimental part, p. 1151 - 1157 (2012/06/04)
High-molecular-weight un-cross-linked poly(p-xylylene) (PPX) derivatives (3) with one lateral linear alkyl substituent (methyl-octyl) on each phenylene moiety were prepared by pyrolysis of corresponding paracyclophanes followed by chemical vapor deposition (CVD). Most of these PPX derivatives showed good solubility in organic solvents which allowed purification by reprecipitation, structural analysis by solution NMR techniques, and molecular weight analysis by gel permeation chromatography. High thermal stability of 3 was found by thermogravimetric analysis. The glass transition temperatures decreased systematically with increasing alkyl chain length from 53 to -23 °C. Increased elongation to break up to 380% was analyzed by stress-strain experiments for as-deposited films indicating excellent coating properties, which were proven by initial coating tests on stents.
NMR studies of bond order in distorted aromatic systems
Gready, Jill E.,Hambley, Trevor W.,Kakiuchi, Kiyomi,Kobiro, Kazuya,Sternhell, Sever,Tansey, Charles W.,Tobe, Yoshito
, p. 7537 - 7540 (2007/10/02)
The 4JH-C=C-Me coupling constant has been previously established1,2 as a probe of bond order. This has now been used to examine the bond orders of compounds containing severely distorted benzene nuclei. In the case of 3,4-di-tert-butyltoluene, no electronic distortions in the aromatic ring can be detected by this method. A series of moderately to severely distorted paracyclophanes show no perturbation of electronic structure, with the possible exception of 8-methyl[6]paracyclophane, which exhibits a barely significant deviation from unstrained values. These conclusions are supported by the results of SCF-MO calculations.
