Synthesis, structure and solid-state emission properties of a vaulted trans -bis(salicylaldiminato)platinum(II) complex bearing a long poly(oxyethylene) spacer

A trans-bis(salicylaldiminato)platinum(II) complex (1) incorporating a 20-membered macrocyclic vaulting structure formed by an ethylenepenta(oxyethylene) bridge was synthesized and subsequently characterized by 1H and 13C NMR, COSY, NOESY, FT-IR, high-resolution mass spectrometry and single crystal XRD. Complex 1 in the crystalline state exhibited intense yellow emission at 298K under UV excitation at 420nm. The mechanistic rationale for the solid-state emission is discussed based on the molecular structure and crystal packing of this complex in comparison with those of an 11 membered, short vaulted analog (2) bearing an ethylenedi(oxyethylene) bridge.