No abstract

A Pt(II) molecular square containing four fluxional trithiacrown ligands at the corners is prepared by transition metal-mediated self-assembly.

The synthesis and crystal structures of four mononuclear Pt II homoleptic complexes with two thiacrown ligands are presented. The binding mode for both macrocycles to the platinum center contrasts with previous structural reports involving identical complex cations but differing anions or crystallization solvents. All three bis(1,4,7-trithiacyclononane(9S3))platinum(II) complexes (with tetrafluoroborate, hexafluorophosphate, and triflate as counterions) are centrosymmetric, with endodentate binding of the trithioether resulting in [S 4 + S 2 ] coordination. The Pt II complex of 1,4,7,10,13,16-hexathiacyclooctadecane(18S6) shows an elongated square pyramidal structure with one exodentate sulfur in a [S 4 + S 1 ] mode. Our work illustrates how changes of counterion and solvent dramatically affect the crystal