Formation of interwoven or partially interwoven metallomacrocyclic networks in copper( II ) or zinc( II ) complexes with N,N′-p-phenylenedimethylenebis(pyridin-4-one)

X-Ray structural studies show that in the compounds [Cu2(p-XBP4)3(NO3)2](NO3)2·2H2O and [Zn2(p-XBP4)4](BF4)4·4H2O [p-XBP4 =N,N′-p-phenylenedimethylenebis(pyridin-4-one)] pyridone oxygen atoms bridge pairs of metal ions to form M2O2 units which, in turn, are linked by p-XBP4 bridges to produce complex arrays of, for Zn, 34- and 38-membered rings or, for Cu, 68-membered rings ‘threaded’ by interwoven p-XBP4 strands.