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-κO,O')copper(II), [Cu(CHFO)(CHNO)] or [Cu(tfpb-κO,O')(pyon-κO)], (I), bis(pyridin-3-ol-κO)bis(4,4,4-trifluoro-3-oxo-1-phenylbutan-1-olato-κO,O')copper(II), [Cu(CHFO)(CHNO)] or [Cu(tfpb-κO,O')(hpy-κO)], (II), and bis(3-hydroxypyridin-2-one-κO)bis(4,4,4-trifluoro-3-oxo-1-phenylbutan-1-olato-κO,O')copper(II), [Cu(CHFO)(CHNO)] or [Cu(tfpb-κO,O')(hpyon-κO)], (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 R(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 R(8) and R(7).