Haar, Christopher M. Nolan, Steven P. Marshall, William J. Moloy, Kenneth G. Prock, Alfred Giering, Warren P. Synthetic, Structural, and Solution Thermochemical Studies in the Dimethylbis(phosphine)platinum(II) System. Dichotomy between Structural and Thermodynamic Trends Reaction enthalpies of the complex (COD)PtMe<sub>2</sub> (COD = η<sup>4</sup>-1,5-cyclooctadiene) with an extensive series of unidentate phosphines have been measured by solution calorimetry. The molecular structures of <i>cis</i>-P<sub>2</sub>PtMe<sub>2</sub> for P = PEt<sub>3</sub>, PMe<sub>2</sub>Ph, P(pyrrolyl)<sub>3</sub>, and PCy<sub>3</sub> have been determined by single-crystal X-ray diffraction. The relative stabilities of the resulting P<sub>2</sub>PtMe<sub>2</sub> complexes are strongly influenced by the size (cone angle) of the incoming phosphine, with larger cone angles resulting in less thermodynamically stable complexes. Crystallographic and <sup>31</sup>P NMR data, however, do not reflect the enthalpic stability scale and are more closely correlated to the electronic (χ) character of the phosphine ligands. The strength of the Pt−P interaction, as determined from these structural data, is greatest for phosphines with electron-withdrawing substituents, regardless of phosphine size or reaction enthalpy. phosphine size;enthalpic stability scale;reaction enthalpy;unidentate phosphines;Solution Thermochemical Studies;cone angles;Structural;phosphine ligands;PEt 3;cone angle;31 P NMR data;PMe 2 Ph;P 2 PtMe 2;PCy 3;Thermodynamic Trends Reaction enthalpies;solution calorimetry;P 2 PtMe 2 complexes 1999-01-16
    https://acs.figshare.com/articles/journal_contribution/Synthetic_Structural_and_Solution_Thermochemical_Studies_in_the_Dimethylbis_phosphine_platinum_II_System_Dichotomy_between_Structural_and_Thermodynamic_Trends/3783372
10.1021/om9807001.s001