Grotjahn, Douglas B. Lo, H. Christine Dinoso, Jason Adkins, Charles D. Li, Chunbang Nolan, Steven P. Hubbard, John L. Studies of the Synthesis and Thermochemistry of Coordinatively Unsaturated Chelate Complexes (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)IrL<sub>2</sub> (L<sub>2</sub> = TsNCH<sub>2</sub>CH<sub>2</sub>NTs, TsNCH<sub>2</sub>CO<sub>2</sub>, CO<sub>2</sub>CO<sub>2</sub>) A comparative synthetic, structural, and thermochemical study on a series of chelate complexes containing the fragment (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir [(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir(TsNCH<sub>2</sub>CH<sub>2</sub>NTs) (<b>1</b>), (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir(TsNCH<sub>2</sub>CO<sub>2</sub>) (<b>2</b>), (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir(CO<sub>2</sub>CO<sub>2</sub>) (<b>3</b>)] was performed to clarify the roles of carboxylato and sulfonamido ligands. Whereas <b>1</b> and <b>2</b> are monomeric in solution and in the solid state, <b>3</b> appears to exist as an oligomer or polymer, (<b>3</b>)<i><sub>n</sub></i>, which can be broken up by addition of a ligand L such as a phosphine, CO, or 2-methoxypyridine to form (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir(L)(CO<sub>2</sub>CO<sub>2</sub>) (<b>6</b>). The synthesis of (<b>3</b>)<i><sub>n</sub></i> from [(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)IrCl(μ-Cl)]<sub>2</sub> required the use of silver oxalate in CH<sub>3</sub>CN, but if other solvents were used, the bridging oxalato complex (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)IrCl(μ-η<sup>2</sup>-η<sup>2</sup>-C<sub>2</sub>O<sub>4</sub>)ClIr(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>) (<b>7</b>) was obtained and identified by X-ray diffraction. Enthalpies for reaction of THF-soluble monomers <b>1</b> and <b>2</b> with PMe<sub>3</sub> were determined to be −28.7(0.5) and −28.5(0.4) kcal mol<sup>-1</sup>, respectively. The oligomerization behavior of <b>3</b> may be a result of reduced σ- or π-donation of carboxylato ligands compared to <i>N</i>-tosylamido ligands, because the values for ν<sub>CO</sub> in oxalato and bissulfonamido complexes <b>6</b>−CO and (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ir(CO)(TsNCH<sub>2</sub>CH<sub>2</sub>NTs) (<b>4</b>−CO) were 2064 and 2042 cm<sup>-1</sup>, respectively. ligand;C 2 O 4;CH 3 CN;TsNCH 2 CO 2;TsNCH 2 CH 2 NTs;Ir;C 5;CO 2 CO 2 2000-05-20
    https://acs.figshare.com/articles/dataset/Studies_of_the_Synthesis_and_Thermochemistry_of_Coordinatively_Unsaturated_Chelate_Complexes_sup_5_sup_-C_sub_5_sub_Me_sub_5_sub_IrL_sub_2_sub_L_sub_2_sub_TsNCH_sub_2_sub_CH_sub_2_sub_NTs_TsNCH_sub_2_sub_CO_sub_2_sub_CO_sub_2_sub_CO_sub_2_sub_/3626136
10.1021/ic990870l.s001