Synthesis, crystal structures, magnetic properties and antimicrobial screening of octahedral nickel(II) complexes with substituted quinolin-8-olates and pyridine ligands

New nickel(II) compounds, viz. trans-[Ni(LHAQ)2(Py)2]·C6H6 (1), cis-[Ni(LHAQ)2(3-MePy)2] (2), cis-[Ni(L2−MeAQ)2(3-MePy)2] (3), trans-[Ni(L4−MeAQ)2(Py)2]·C6H6 (4), trans-[Ni(L4−OMeAQ)2(Py)2]·C6H6 (5), trans-[Ni(L4−OEtAQ)2(Py)2]·C6H6 (6), trans-[Ni(L4−BrAQ)2(Py)2]·C6H6 (7) and trans-[Ni(L4−ClAQ)2(3-MePy)2]·2(3-MePy) (8) (primary ligands: LXAQ = substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py = pyridine or...