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)]center dot 2Phenanthrene

The synthesis and crystal structure of [Co(4,4'-bipyridine)(2.5)(NO3)(3)] . 2C(14)H(10), 1 . 2C(14)H(10), are presented and discussed in the context o f recent developments in the field of coordination polymers. 1 adapts a "mo lecular railroad" architecture and is closely related to two previously rep orted molecular railroads in that it contains both bridging and terminal sp acer ligands. However, it differs in two important aspects. First, because 1 is uncharged its crystal packing is dominated by stacking interactions be tween aromatic moieties rather than hydrogen bonding or interpenetration. S econd, the resulting open framework planar architecture of 1 sustains coexi stence with two topologically complementary sets of phenanthrene molecules, One of these sets can be regarded as a planar network of (4,4) topology wh ereas the other is an achiral chain of phenanthrene molecules that fills th e channels that are generated by the interpenetration of the two planar net works. (C) 2000 Academic Press.