Synthesis and structural studies of ruthenium(II) and rhodium(IV) complexes bearing tridentate sulfoxide Schiff base ligands

One new sulfoxide-containing Schiff base, (<i>E</i>)-4-chloro-2-((2-(methylsulfinyl phenyl)imino)methyl) phenol (<b>HL</b>) was coordinated with ruthenium and rhodium, affording five ruthenium(II) complexes [RuCl(<b>L</b>)(CO)₂] (<b>1</b>), [RuCl(<b>L</b>)(dmso)₂] (dmso = dimethylsulfoxide, <b>2</b>), [RuCl(<b>L</b>)(PPh₃)(CH₃CN)] (<b>3</b>), [RuCl(<b>L</b>)(CO)(PPh₃)] (<b>4</b>), [RuCl(<i>NOS</i>-<b>L</b>H₂)(CO)(PPh₃)] (<b>5</b>) and one rhodium(IV) complex [RhCl₃(<b>L</b>)] (<b>6</b>). Molecular structures of H<b>L</b> and complexes <b>1</b>–<b>6</b> were established by single crystal X-ray diffraction analysis. Moreover, the free ligand H<b>L</b> and its complexes <b>1</b>–<b>6</b> were characterized by infrared, NMR, UV-vis, and fluorescence spectroscopies, and their electrochemical properties were also investigated. The ruthenium complexes showed good catalytic activity for the cyclopropylation of styrene.