Copper(II) bis(4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dionate) complexes with pyridin‐2‐one, 3‐hydroxypyridine and 3‐hydroxypyridin‐2‐one ligands: molecular structures and hydrogen‐bonded networks

Copper(II) bis(4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dionate) complexes with pyridin‐2‐one (pyon), 3‐hydroxypyridine (hpy) and 3‐hydroxypyridin‐2‐one (hpyon) were prepared and the solid‐state structures of (pyridin‐2‐one‐κO)bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ2O,O′)copper(II), [Cu(C10H6F3O2)2(C5H5NO)] or [Cu(tfpb‐κ2O,O′)2(pyon‐κO)], (I), bis(pyridin‐3‐ol‐κO)bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ2O,O′)copper(II), [Cu(C10H6F3O2)2(C5H5NO)2] or [Cu(tfpb‐κ2O,O′)2(hpy‐κO)2], (II), and bis(3‐hydroxypyridin‐2‐one‐κO)bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ2O,O′)copper(II), [Cu(C10H6F3O2)2(C5H5NO2)2] or [Cu(tfpb‐κ2O,O′)2(hpyon‐κO)2], (III), were determined by single‐crystal X‐ray analysis. The coordination of the metal centre is square pyramidal and displays a rare example of a mutual cis arrangement of the β‐diketonate ligands in (I) and a trans‐octahedral arrangement in (II) and (III). Complex (II) presents the first crystallographic evidence of κO‐monodentate hpy ligation to the transition metal enabling the pyridine N atom to participate in a two‐dimensional hydrogen‐bonded network through O—H…N interactions, forming a graph‐set motif R22(7) through a C—H…O interaction. Complex (III) presents the first crystallographic evidence of monodentate coordination of the neutral hpyon ligand to a metal centre and a two‐dimensional hydrogen‐bonded network is formed through N—H…O interactions facilitated by C—H…O interactions, forming the graph‐set motifs R22(8) and R22(7). The influence of tautomeric forms and different coordination modes has been studied with respect to the formation of hydrogen‐bonded networks in (4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dionato)copper(II) moieties in the presence of pyridin‐2‐one, 3‐hydroxypyridine and 3‐hydroxypyridin‐2‐one.