Structural diversity of copper(I)-ethylene complexes with 2,4-bis(2-pyridyl)pyrimidine directed by anions.

The 3 : 1 reaction of [Cu(C 2 H 4 ) n ]ClO 4 with 2,4-bis(2-pyridyl)pyrimidine (bpprd) in Me 2 CO under C 2 H 4 afforded yellow prism crystals of the dinuclear Cu(I)-C 2 H 4 complex [Cu 2 (bpprd)(η 2 -C 2 H 4 ) 2 (ClO 4 ) 2 ] (1). The 3 : 1 reaction of [Cu(C 2 H 4 ) n ]NO 3 with bpprd in Me 2 CO under C 2 H 4 afforded yellow plate crystals of the tetranuclear Cu(I)-C 2 H 4 complex [Cu 4 (bpprd) 2 (η 2 -C 2 H 4 ) 4 (μ-NO 3 ) 2 ](NO 3 ) 2 (2). The 10 : 1 reaction of [Cu(C 2 H 4 ) n ]BF 4 with bpprd in Me 2 CO under C 2 H 4 afforded yellow plate crystals of the dinuclear Cu(I)-C 2 H 4 complex [Cu 2 (bpprd)(η 2 -C 2 H 4 ) 2 (BF 4 )]BF 4 (3). The 3 : 1 reaction of [Cu(C 2 H 4 ) n ]BF 4 with bpprd in Me 2 CO under C 2 H 4 afforded red prism crystals of the polymeric Cu(I)-C 2 H 4 complex {[Cu 6 (bpprd) 4 (η 2 -C 2 H 4 ) 2 (μ-η 2 :η 2 -C 2 H 4 )(μ-BF 4 ) 2 ](BF 4 ) 4 } n (4). The X-ray crystal structures of complexes 1-4 have been determined. The structural diversity of Cu(I)-C 2 H 4 complexes bridged by bpprd with different anions was demonstrated. The 1D Cu(I)-bpprd/C 2 H 4 coordination polymer 4 bridged by unusual μ-η 2 :η 2 -C 2 H 4 and the μ-BF 4 - anion is of particular significance. Complex 1 exhibited relatively well-resolved 1 H NMR signals of bpprd and C 2 H 4 ( δ = 4.97 ppm) in (CD 3 ) 2 CO at 23 °C.