A neutral 'molecular railroad' coordination polymer that incorporates polycyclic aromatic molecules: Synthesis and single-crystal X-ray structure of [co(4,4'bipyridine)_2.5(No₃)₂]· 2phenanthrene

The synthesis and crystal structure of [Co(4,4'Bipyridine)_2.5(NO₃)₃]·2C₁₄H₁₀, 1 · 2C₁₄H₁₀, are presented and discussed in the context of recent developments in the field of coordination polymers. 1 adapts a 'Molecular railroad' architecture and is closely related to two previously reported molecular railroads in that it contains both bridging and terminal spacer ligands. However, it differs in two important aspects. First, because 1 is uncharged its crystal packing is dominated by stacking interactions between aromatic moieties rather than hydrogen bonding or interpenetration. Second, the resulting open framework planar architecture of 1 sustains coexistence with two topologically complementary sets of phenanthrene molecules. One of these sets can be regarded as a planar network of (4,4) topology whereas the other is an achiral chain of phenanthrene molecules that fills the channels that are generated by the interpenetration of the two planar networks. (C) 2000 Academic Press.