Synthesis, crystal structure, spectral and thermal investigations of morpholinyldithiocarbamate complexes: A novel coordinated precursors for efficient metal oxide nanophotocatalysts

The monovalent Na(I) and divalent [Ni(II), Cu(II), and Zn(II)] complexes of the morpholinyldithiocarbamate ligand have been synthesized and characterized using analytical, spectral and thermal measurements. The crystal structure of the polymeric [Na{S₂CN(CH₂CH₂)₂O}(H₂O)₂]_n complex (1) was elucidated by X-ray single crystal diffraction. Complex (1) crystalizes in the orthorhombic space group P c a 21, with Z = 4. The morpholinyldithiocarbamate ligand in (1) acts as a bidentate bridging ligand between sodium ions via one S atom while, the other sulfur remains uncoordinated. The coordinated H₂O molecules act as bidentate bridges between sodium ions. Each Na ion in (1) participates in two planar four membered rings of [Na₂O₂] arrangements, which bonded through bridging sulfur–sodium bonds leading to polymeric supramolecular structure. In an attempt to convert coordination compounds to metal oxide nanoparticle (MONPs), the Ni(II), Cu(II) and Zn(II) complexes (2–4) were used for the preparation of NiO, CuO and ZnO MONPs through solid state thermal decomposition as monocular source precursors. The obtained MONPs were characterized via XRD, XPS, and UV–Vis spectra and their morphology was investigated by TEM. The photocatalytic activity of MONPs was examined for methylene blue (MB) photodegradation. The MONPs showed high photocatalytic efficiencies of CuO (92.7%) > NiO (83.7%) > ZnO (75.5%). The reported method provides a generalized and systematic way for preparation of many metal oxides with manageable and reproducible features.