Synthesis, characterisation and optical spectroscopy of platinum(ii) di-ynes and poly-ynes incorporating condensed aromatic spacers in the backbone
Abstract
A series of protected and terminal dialkynes with extended π-conjugation through a condensed aromatic linker unit in the backbone, 1,4-bis(trimethylsilylethynyl)naphthalene, 2a, C–R–C
C–Pt(PEt3)2Ph]
(R = benzene-1,4-diyl 1c; naphthalene-1,4-diyl 2c and anthracene-9,10-diyl 3c) while reactions between equimolar quantities of trans-[(nBu3P)2PtCl2] and 2b–3b under similar conditions readily afforded the platinum(II) poly-ynes trans-[–(nBu3P)2Pt–C
C–R–C
C–]n
(R = naphthalene-1,4-diyl 2d and anthracene-9,10-diyl 3d). The Pt(II) diynes and poly-ynes have been characterized by analytical and spectroscopic methods, and the single crystal X-ray structures of 1c and 2c have been determined. These structures confirm the trans-square planar geometry at the platinum centres and the linear nature of the molecules. The di-ynes and poly-ynes are soluble in organic