Structural, thermal, and magnetic properties of three transition metal-4,4′-bipyridine coordination polymers: [Ni(4,4′-bipy)3(H2O)2](ClO4)2·1.4(4,4′-bipy)·3(H2O); [Co(4,4′-bipy)3(H2O)2](ClO4)2·1.4(4,4′-bipy)·3(H2O); [Cu(4,4′-bipy)3(DMSO)2](ClO4)2·2(4,4′-bipy)