Thermal and Photochemistry of Perfluoro-1,6-heptadiene and the Perfluoro-1,3,6-heptatrienes
作者:Naiyong Jing、David M. Lemal
DOI:10.1021/jo00106a019
日期:1995.1
Pyrolysis transformed the title diene (1) into a 9:1 mixture of perfluorobicyclo[3.1.1]heptane (2) and cis-perfluorobicyclo[3.2.0]heptane (3) at 300 degrees C and at > 450 degrees C principally into perfluarocyclopentene (11). Mercury-sensitized vapor phase photolysis of 1 also yielded 2 and 3, but the latter now dominated and its trans isomer 13 was formed as well. In the presence of nitrogen as a bath gas, the product was further enriched in the [3.2.0] isomers. Radical bromination of 1, a model reaction for the triplet photocyclization, gave cis- and trans-perfluoro-1,2-bis(bromomethyl)cyclopentane (IB). Configurations were assigned to the cis and trans isomers of perfluoro-1,3,6-heptatriene (19 and 20), and they were equilibrated with iodine/visible light (K-t-->c = 1.6(7) in CDCl3, 14 degrees C). The cis triene underwent electrocyclization at 133 degrees C to perfluoro-3-allylcyclobutene (27); thermal ring opening of this cyclobutene yielded exclusively the cis isomer. At 250 degrees C both the cis triene and the allylcyclobutene were transformed quantitatively into perfluorobicyclo[3.1.1]hept-2-ene (28). Trans triene gave no detectable cyclobutene over a range of temperatures, but yielded the [3.1.1] compound at 250 degrees C. Ultraviolet irradiation of cis triene produced the allylcyclobutene, and mercury photosensitization of either compound (or the trans triene) proceeded a step farther to give tricycloheptane valence isomers (31 and 32). The internal [2 + 2] cycloadditions described here contribute to our knowledge of the ground rules for reactions of this type in unsaturated fluorocarbons.
Anti-Corrosion Conformal Coating for Metal Conductors Electrically Connecting an Electronic Component
申请人:Boday Dylan Joseph
公开号:US20110189381A1
公开(公告)日:2011-08-04
An apparatus includes an electronic component mounted on a substrate and metal conductors electrically connecting the electronic component. A conformal coating overlies the metal conductors and comprises a polymer into which a phosphine compound is impregnated and/or covalently bonded. Accordingly, the conformal coating is able to protect the metal conductors from corrosion caused by sulfur components (e.g., elemental sulfur, hydrogen sulfide, and/or sulfur oxides) in the air. That is, the phosphine compound in the polymer reacts with any corrosion inducing sulfur component in the air and prevents the sulfur component from reacting with the underlying metal conductors. Preferably, the phosphine compound in the polymer does not react with other components in the air (e.g., carbon dioxide) which would otherwise deplete its availability for the target reaction. The phosphine compound may be rendered completely non-volatile by covalently bonding it directly into the polymer backbone.
ANTI-CORROSION CONFORMAL COATING COMPRISING MODIFIED POROUS SILICA FILLERS FOR METAL CONDUCTORS ELECTRICALLY CONNECTING AN ELECTRONIC COMPONENT
申请人:Boday Dylan J.
公开号:US20130213707A1
公开(公告)日:2013-08-22
A conformal coating comprising modified porous silica particles is disclosed. A porous silica particle, such as MCM-14 or SBA-15 is modified with a sulfur gettering functionality, such as a phosphine compound, covalently bonded to silicon atoms in the porous silica particle. The conformal coating comprising the modified porous silica particles may be applied to metallic wiring areas of a circuit component, with the sulfur gettering functionality preventing sulfur from atmospheric gasses from penetrating the conformal coating to the metallic wiring.