Synthesis and crystal structures of copper(II) dinuclear complex and zinc(II) coordination polymer as materials for efficient oxidative desulfurization of dibenzothiophene
The synthesis, structure and physical properties of a dinuclear copper(II) complex [Cu2(BAc)4(QX)2], and 2D zinc(II) Coordination polymer, [Zn(TDPA)2(TMPy)2]n, (where HBAc= 4-hydroxyl benzoic acid; QX= quinoxaline; HTDPA = 3,3-thiodipropionic acid; TMPy = 4,4-Trimethylenedipyridine) were presented. The complexes were characterised by elemental analysis, FT-IR, electronic spectroscopy and thermogravimetric analysis. The structures of all the complexes were determined by single crystal X-ray diffraction studies. The geometry around Cu(II) of [Cu2(BAc)4(QX)2], is slightly distorted square pyramidal, with four oxygen atoms of carboxylate occupying the trans oreintation and one quinoxaline molecule occupying the axial position. [Zn(TDPA)2(TMPy)2]n coordination polymer are linked by two (μ-N)2 Coordination TMPy and two (μ-O)2 (halves) from (TDPA)-. Zn(TDPA)2(TMPy)2]n stacks in layers with disordered water molecules in the voids. The work further investigated [Cu2(BAc)4(QX)2] catalysed oxidation of dibenzothiophene (DBT) followed by the adsorption of the resulting dibenzothiophene sulfoxide (DBTO) over [Zn(TDPA)2(TMPy)2]n. The theoretical strength of adsorption is in the order of DBTO-[Zn(TDPA)2(TMPy)2]n (Binding Energy of −53.10 kJ/mol) > DBT-[Zn(TDPA)2(TMPy)2]n (Binding Energy of −38.53 kJ/mol) suggesting that the presence of oxygen influences the adsorption process. The use of [Cu2(BAc)4(QX)2] and [Zn(TDPA)2(TMPy)2]n in model fuel resulted in 97% oxidation of DBT with adsorption capacity of 35.5 mg/g, respectively.