Linking triangles: synthesis and structure of [Cu 3(phen) 4(PPh 3)](BF 4) 3 · X and [Cu 5(phen) 7](BF 4) 5 · 4(NO 2C 6H 5) (phen=4,7-phenanthroline and X=Et 2O or 2 THF)

Abstract

Two new coordination polymers containing Cu(I) and 4,7-phenanthroline (phen) have been synthesized and structurally characterized. 1a, [Cu 3(phen) 4(PPh 3)](BF 4) 3 · 2(THF), crystallizes in the triclinic space group P 1 ̄ with a=11.5407(6) Å, b=14.5687(7) Å, c=23.579(1) Å, α=74.203(1)°, β=80.530(1)°, γ=83.998(1)°, and Z=2. 1b (isostructural with 1a), [Cu 3(phen) 4(PPh 3)](BF 4) 3 · Et 2O, also crystallizes in the triclinic, space group P 1 ̄ , with a=11.4920(6) Å, b=14.5074(8) Å, c=23.749(1) Å, α=73.599(1)°, β=79.871(1)°, γ=83.814(1)°, and Z=2. 2, [Cu 5(phen) 7](BF 4) 3 · 4(NO 2Ph), crystallizes in the triclinic space group P 1 ̄ , with a=11.7867(9) Å, b=14.5076(1) Å, c=15.946(1) Å, α=100.076(1)°, β=106.637(1)°, γ=95.612(1)°, and Z=1. Three unique copper atoms reside in the asymmetric units of all three compounds; each display trigonal Y-shaped coordination environments. For 1, (Cu 3phen 3) +3 bowl shaped triangles are linked through a phen bridge into one-dimensional chains. In 2, two Cu(I) cations have similar coordination environments containing three bridging phen ligands, but the third Cu(I) cation is coordinated by two fully occupied phen ligands, as well as a one-half occupied phen ligand, or a one half-occupied BF 4 − anion which sit roughly on the same general position. The Cu(I) centers are linked through the phen ligands to form a ladder-like structure composed of two disordered chains (similar to those seen in 1) fused together. Extensive π–π stacking interactions are observed in both 1 and 2.