Photosensitizers, copper -based

Fig. 25. Comparison of the sunlight harvesting features of tris(2,2 -bipyridyl)ruthenium (9) and a copper-based multielectron transfer photosensitizer (138) carrying a 7i-acceptor ligand of the BIAN-type (13)...

Luo S, Mejia E, Friedrich A, Pazidis A, Junge H, Surkus A, Jackstell R, Demirra S, Gladiali S, Lochbnmner S, Beller M (2013) Photocatalytic water reduction with copper-based photosensitizers a noble-metal-free system. Angew Chem Int Ed 52 419-423... 

The use of printed circuits reduces significantly the time necessary to wire electronic apparatus. The design of the circuit ensures that contacts between the components may be provided by a metal coating on an insulating base that is covered with a thin copper layer. Poly(vinyl alcohol)/dichromate or any usable photosensitive system is applied to the copper. The resist is hardened, and the copper regions not forming part of the circuit are removed by etching with aqueous ferric chloride or peroxodisuUate solution. 

The second method is based on the use of polyimides with lower glass transition temperatures that can be melt-processed. For example, intrinsically photosensitive preimidized polymers formed by reacting 3,3 4,4 -benzopheno-netetracarboxylic acid dianhydride (BTDA) with methyl-substituted 4,4 -methylenebisbenzeneamine (MDA), blended to epoxy resins, give high strength laminate with copper. Poly(isoimides), which exhibit good melt-flow properties before thermal isomerization to imides, are also used to make flexible circuits. In the last process copper is electroless plated on polyimide film such as Kapton 200H. 

More recently, it was found that the aerobic CDC reaction between N-heterocyclic sp C-H bonds and the sp C-H bonds of TV-alkyl tertiary amines could be promoted by copper, vanadium, antimony, and photosensitive platinum catalysts. Generally, successful methodologies offered the possibility to functionalize the sp C center with a variety of nucleophiles, as illustrated by the recently reported organocatalytic system based on molecular iodine (Scheme 9.27). ... 

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