Synthesis, structure and reactivity of homobimetallic Rh(I) and Ir(I) complexes of s- and as-indacene-diide

New Rh derivatives of s-indacene active in dehydrogenative silylation of styrene

“…In our case where two different pathways were used, implying various reactional intermediates but the same deprotonation/metallation procedures, it seems reasonable to envisage that the same hypothesis (dominant influence of the COD ligand) could explain the identical ratio obtained for the two paths. Meanwhile, this chelating olefin affords a smaller excess of the syn isomer than that obtained for sindacenediide spacer (90%) [13]. This presumably results from the slightly higher hindrance of the alkylated s-indacene compared to that of the unsubstituted analogue.…”

“…Among them, we can cite: the structures and the relative stabilities of both the lithiated intermediates and the metal dimers, the steric hindrance, the solvent effect (THF), the influence of the ancillary ligand of rhodium (COD vs. CO). Ceccon et al [13] who studied in more details this aspect, concluded that the role of ligand seems preponderant: a large preference for the syn isomer was observed with ancillary ligands as COD or NBD and for the anti form with CO. In our case where two different pathways were used, implying various reactional intermediates but the same deprotonation/metallation procedures, it seems reasonable to envisage that the same hypothesis (dominant influence of the COD ligand) could explain the identical ratio obtained for the two paths.…”

From polysubstituted 1,5-dihydro-s-indacene lithium derivatives to polysubstituted hydro-s-indacenyl radicals by a new method involving a single electron transfer from an electron rich olefin

“…Polyalkyl-s-indacenes have been synthesized and studied for the last fifty years for their use as ligands or spacers in the synthesis of binuclear complexes, in conducting polymers or biological compounds [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, literature reports only some examples of s-indacenyl and substituted s-indacenyl radical ions [16,19] and to the best of our knowledge no examples of substituted s-indacenyl radicals.…”

Preparation and ESR characterization of polyalkyl-s-indacenyl anion-radicals from polyalkyl-1,5-dilithio-s-indacenes

“…To (ii) frozen in liquid nitrogen was added a solution of Cp 2 Fe + BF 4 À in dichloromethane and the ESR spectrum was recorded at 243 K.…”

“…Because of their potential use as ligands or spacers in the synthesis of binuclear complexes, conducting polymers and biological compounds, polyalkyl-s-indacenes and polyalkyl-1,5-dihydro-sindacenes, as well as some of their radical anions, radical cations or radicals have been prepared and studied [1][2][3][4][5][6][7][8][9][10].…”