Synthesis of new bis(acetylide)-substituted fluorene derivatives and their bimetallic and polymeric complexes

A new series of bis(acetylide) organic ligands having fluorene or fluorenone moieties in the backbone, 2,7-di(trimethylsilylethynyl)fluorene (1a), 2,7-di(ethynyl)fluorene (1b), 2,7-di(trimethylsilylethynyl)fluoren-9-one (2a) and 2,7-di(ethynyl)fluoren-9-one (2b), has been prepared. Reaction of the diterminal alkynyl fluorene derivatives Ib and 2b with two equivalents of the complex trans-[(Ph)(PEt3)(2)Pt(Cl)] in CH2Cl2/(Pr2NH)-Pr-i with catalyic CuI readily affords the diplatinum(II) bis(acetylide) complexes trans-[(Ph)(PEt3)(2)Pt-C=C-R-2-C=C-Pt(PEt3)(2)(Ph)] (R-1 = 2,7-fluorenyl 3) and trans-[(Ph)(PEt3)(2)Pt-C=C-R-2-C=C-Pt(PEt3)(2)(Ph)] (R-2 = 2,7-fluoren-9-onyl 4) in good yields. Two new rigid-rod organometallic polymers trans-[-Pt(PBu3n)(2)-C=C-R-1-C=C-]infinity (5) and trans-[-Pt(PBu3n)(2)-C=C-R-2-C=C-]infinity (6) have also been prepared in good yields, in a similar manner to their dinuclear complexes 3 and 4, by the CuI-catalysed dehydrohalogenation reaction of trans-[Pt(PBu3n)(2)Cl-2] with one equivalent of 1b or 2b, in an amine solvent, at ambient temperature. Both poly-yne polymers (colourless 5, deep red 6) exhibit good solubility in common organic solvents and readily cast into thin films. The organometallic terminal alkyne complexes trans-[Cl(dppm)(2)M-C=C-R-2-C=CH] (M = Ru 7, Os 8), obtained by treatment of 2b with one equivalent of cis-[M(dppm)(2)Cl-2] (M = Ru, Os), based on a NaPF6/DBU method have been utilised as starting products for access to the homobimetallic trans-[Cl(dppm)(2)M-C=C-R-2-C=C-M(dppm)(2)Cl] (M = Ru 9, Os 10) and heterobimetallic trans-[Cl(dppm)(2)Ru-C=C-R-2-C=C-Os(dppm)(2)Cl] (11) systems by reaction with a suitable choice of cis-M(dppm)(2)Cl-2 (M = Ru or Os). All the new compounds have been characterised by analytical and spectroscopic methods, and the single-crystal X-ray structure of 1b has been determined. (C) 1998 Elsevier Science S.A. All rights reserved.