One pair of reactants, Cu(hfac)(2) = M and the hinge-flexible radical ligand 5-(3-N-tert-butyl-N-aminoxylphenyl)pyrimidine (3PPN = L), yields a diverse set of five coordination complexes: a cyclic loop M2L1 dimer; a 1:1 cocrystal between an M2L2 loop and an ML2 fragment; a ID chain of M2L2 loops linked by M; two 2D M3L2 networks of (M-L)(n) chains crosslinked by M with different repeat length pitches; a 3D M3L2 network of M2L2 loops cross-linking (M-L)(n)-type chains with connectivity different from those in the 2D networks. Most of the higher dimensional complexes exhibit reversible, temperature-dependent spin-state conversion of high-temperature paramagnetic states to lower magnetic moment states having antiferromagnetic exchange within Cu-ON bonds upon cooling, with accompanying bond contraction. The 3D complex also exhibited antiferromagnetic exchange between Cu-II ions linked in chains through pyrimidine rings.