Studies on the Chelation of Cyclodiphosph(V)azane Complexes of Co(II), Ni(II), Cu(II), and Pd(II): Preparation,Characterization, Thermal,Solid State Electrical Conductivity,and Biological Activity Studies

Cyclodiphosph(V)azane of chromene, (1,3-diphenyl-2,4-bis(3-amino-9-methoxy1-tolyl-3H-benzof]chromene-2-carbonitrile)-2,2,4,4-tetrachlorocyclodiphosph(V)azane (III), reacts with stoichiometric amounts of transition metal salts such as Co(II), Ni(II), Cu(II), and Pd(II) to afford colored complexes in a moderate to high yield. The structure of the isolated complexes was suggested based on elemental analyses, IR, molar conductance, UV-Vis, ¹H, ¹³C, and ³¹P-NMR, magnetic susceptibility measurements, and dark electrical conductivity of solid state from room temperature up to 450 K. The complexes have been investigated in solution by spectrophotometric molar ratio and conductometric methods. Kinetic and thermodynamic parameters were computed from the thermal decomposition data using the Coats and Redfern method. The prepared complexes showed high to moderate bactericidal activity compared with the ligand.