A mixed-ligand coordination polymer from the in situ, Cu(I)-mediated isomerization of bis(4-pyridyl)ethylene

Reaction of [Cu(PPh(3))(2)(MeCN)(2)]PF(6) and trans-1,2-bis(4-pyridyl)ethylene (bpe) results in the trans-cis isomerization of the bpe and subsequent formation of a mixed-isomer linear coordination polymer over the course of several days or weeks depending on solvent. The one unique copper atom in the structure is coordinated to two bridging cis-bpe ligands, one bridging trans-bpe ligand, and one terminal triphenylphoshine ligand to create [Cu(trans-bpe)(0.5)(cis-bpe)(PPh(3))](+)( infinity ) zigzag chains. The reaction requires both visible light and Cu(I), and the crystallization of this particular coordination polymer is insensitive to the ratio of trans:cis isomers in solution, occurring both from trans-rich and cis-rich solutions.