Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O yield of 60%. It crystallized the triclinic space group P1 cell parameters: = 7.684(1) Å, b 9.011(1) c 10.874(1) ? 72.151(2)°, ? 70.278(2)°, ? 80.430(2)°, V 670.0(1) Å3, Z 2 at 100 K. 1 composed K+, mo...