The new polymeric compounds [{M(bpen)X}∞] [M = CuI, X = PF6-, 1
M = AgI, X = ClO4-, 2
bpen = trans-1,2-bis(2-pyridyl)ethylene] and [{Cu(bpen)(CO)(CH3CN)(PF6)}∞] 3 have been synthesised and their structures determined by X-ray crystallography: 1, monoclinic, space group P21/n, a = 13.653(8), b = 9.288(3), c = 11.232(3) Å, β = 96.89(3)° and Z = 4
2, triclinic, space group P1, a = 7.569(1), b = 13.253(5), c = 6.757(1) Å, α = 92.24(3), β = 104.05(1), γ = 78.41(3)° and Z = 2
3, triclinic, space group P1, a = 9.882(8), b = 12.126(9), c = 8.173(8) Å, α = 93.33(9), β = 102.10(9), γ = 106.90(7)° and Z = 2. The complexes show an infinite-chain structure of macrocations with non-interacting PF6- or ClO4- anions. Compounds 1 and 2 are unique polymers having a linear co-ordination geometry, characteristic of d10 metals. They differ in the mode of polymerization, being of rectangular and triangular wave chain types, respectively. A non-coplanar structure between the pyridyl and olefinic groups of the co-ordinated bpen is recognized, indicative of the importance of intermolecular interaction in crystal packing. Compound 3 has a tetrahedral form of copper(I) as a repeating unit, involving a single CO molecule, which exhibits a short C=O distance [1.104(6) Å] irrespective of the normal ν(CO) value (2088 cm-1). Proton NMR spectra of the copper(I)-bpen systems demonstrate that the solution species has a dimeric structure having two bridging bpen, where the olefinic moiety is co-ordinated to copper(I), dissimilar to the co-ordination mode of 1. A difference in chemical shifts between the PF6- and ClO4- salts is observed, indicative of the interaction of ClO4- with copper(I). The polymeric complex is predominantly obtained from the PF6- salt. The formation and the structure of CO or C2H4 adducts in solution have also been examined by 1H NMR spectroscopy.