Correction of the space group of [Ni(biPY)(2)(ONO2)(2)]center dot 2(pyrene)

The crystal structure of [Ni(bipy)(2)(ONO2)(2)].2(pyrene), poly[[ [bis (nit rato-O) nickel(II)]bis(mu -4,4'-bipyridyl-N,N'] bis-(pyrene)], was original ly reported in space group Pn [Biradha et al (1999). Chem. Commun. pp. 1327 -1328]. Reasons are given for changing the space group to P2(1)/n. Conseque ntly, incorrect descriptions of the title compound in the literature must b e altered. In particular, the structure is not polar. It is further contend ed that description in terms of 'complementary, interpenetrating covalent a nd noncovalent two-dimensional networks' is misleading as the 'noncovalent network' (of pyrenes) has geometrical but not physical significance. The ti tle compound is a typical host-guest inclusion complex.