The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Vinylmetallics as ligands. II. Reaction of (1,5-cyclooctadiene)copper(I) chloride with dimethyldivinylsilane and dibutyldivinyltin》. Authors are Fitch, John W.; Kettner, Charles A..The article about the compound:Chloro(1,5-cyclooctadiene)copper(I) dimercas:32717-95-6,SMILESS:C12=C(CCC3=C4CC2)[Cu+]1534[Cl-][Cu+]678(C9=C6CCC7=C8CC9)[Cl-]5).Synthetic Route of C16H16Cl2Cu2. Through the article, more information about this compound (cas:32717-95-6) is conveyed.
The stability of Me2Si(CH:CH2).2CuCl and Bu2Sn(CH:CH2)2.2CuCl was compared to that of 1,5-cyclooctadiene-CuCl. Both ligand exchange reactions and competition reactions favored the formation of the vinylmetallic complexes over formation of 1,5-cyclooctadiene-CuCl.
If you want to learn more about this compound(Chloro(1,5-cyclooctadiene)copper(I) dimer)Synthetic Route of C16H16Cl2Cu2, you may wish to communicate with the author of the article,or consult the relevant literature related to this compound(32717-95-6).
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider