Anodic behavior of crowded triarylphosphines. ESR study of triarylphosphoniumyl radicals, Ar3P.bul.+
摘要:
A large number of triarylphosphines exhibiting different steric hindrance has been prepared. The pyramidalization angle alpha of these compounds was calculated with use of the MM2 force field and was shown to depend almost exclusively on the number of ortho substituents on the phenyl rings. In a series of isosteric (same alpha) phosphines, the oxidation potential correlates with the sum of the sigma+ Hammett parameters of the phenyl substituents. In the absence of oxygen, anodic oxidation of all the triarylphosphines bearing two o-methyl substituents on each phenyl ring is reversible and yields very persistent phosphoniumyl radicals. These radicals are easily detected by ESR in liquid solution and were shown to retain a pyramidal geometry that is significantly flattened compared to that of the parent phosphine.
EPOXY RESIN MOLDING MATERIAL FOR SEALING AND ELECTRONIC COMPONENT DEVICE
申请人:Hamada Mitsuyoshi
公开号:US20090326100A1
公开(公告)日:2009-12-31
The present invention provides an epoxy resin molding material for sealing that is excellent in fluidability and solder reflow resistance without lowering the curability thereof, and an electronic component device provided with an element sealed with the material. The epoxy resin molding material for sealing, comprising (A) an epoxy resin, (B) a curing agent, (C) a curing accelerating agent, (D) an inorganic filler, and (E) an alkoxysilane polymer, wherein the alkoxysilane polymer (E) is a polymer obtained by polymerizing an alkoxysilyl group moiety of a specific alkoxysilane compound.