aromatic nitration with carboxylic anhydride-inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)3, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifluoromethanesulfonate (scandium(III) triflate, Sc(OTf)3) is the most active catalyst among our tested Lewis acids. It was also found that acetic anhydride-Al(NO3)
BARBA N. A.; POGREBNOJ I. L.; SHUKLA R. K., REDKOLLEGIYA ZH. IZV. VYSSH UCHEB.
作者:BARBA N. A.、 POGREBNOJ I. L.、 SHUKLA R. K.
DOI:——
日期:——
Color forming compositions and associated methods
申请人:Bhatt Jayprakash C.
公开号:US20070269737A1
公开(公告)日:2007-11-22
Compositions and methods for forming color images on a substrate capable of development at desired wavelengths or energy levels are disclosed and described. The color forming composition can include a carrier system and a latent pigment with a pendent group, wherein the latent pigment is colorless or pale in color while the pendent group is attached, and wherein the latent pigment is convertible to a colored pigment upon removal of the pendent group. Alternatively, the latent pigment can have multiple states of conjugation where the latent pigment is colorless or pale in a first conjugation state, and colored in a second conjugation state. The color forming compositions are useful in forming images on a wide variety of substrates, such as optical disks.