Synthesis and Structural Characterization of a New Tetranuclear Nickel(II) Sulfato Complex Containing the Anionic Form of Di-2-Pyridyl Ketone Oxime

Abstract

The preparation and crystal structure of a tetranuclear Ni(II) sulfato cluster containing the anion of di-2-pyridyl ketone oxime, (py)2CNO−, are reported. Treatment of NiSO4·6H2O with one equivalent of (py)2CNOH and one equivalent of NEt3in MeOH leads to the compound [Ni4{(py)2CNO}4(SO4)2(MeOH)4] (1) in moderate yield. The metal ions are linked together by two 3.2111 and two 2.1110 (Harris notation) (py)2CNO−ligands, as well as two 2.1100 SO42−ions to create a rare metallacrown-type (12-MC-4) ring. Strong H-bond intermolecular interactions in1lead to the formation of a 1D chain along the axis. Characteristic IR bands are discussed in terms of the known structure of1.

Equilibrium studies of cobalt(II) extraction with 2-pyridineketoxime from mixed sulphate/chloride solution

“…According the equation, the slope of the straight line given in the pH range between 1 and 3 should be close to 1 or its multiple, but it was found to be 0.52. That suggests that cobalt(II) ions coordination is a result of a binuclear complex formation stabilised by intramolecular hydrogen bond O–H–O [22, 23]. This theory could be confirmed by the logarithmic plot of the cobalt(II) distribution coefficient for the binuclear complex () versus equilibrium pH.…”

Template arrangement of {Ni3(μ3-OH)(SO4)(R-NO)2}+ fragments around Na+ cations: An unprecedented {Ni12Na} unit linked by oximate and sulfate bridges

“…Although sulfate anions present great coordinative possibilities (they can bind up to 10 metal ions) [5], and have shown interesting properties in different fields such as catalysis, medicinal, bioinorganic and environmental chemistry [5], its use in coordination chemistry is limited and currently, only six entries were found in CCDC containing the simultaneous sulfate and oximate bridges being practically all of them are NiII derivatives such as Ni4 [6], two Ni5 [7], a family of Ni6 [8] and one Ni8 [9] clusters.…”