10.1021/om0003640.s001 Munetaka Akita Munetaka Akita Mariko Hashimoto Mariko Hashimoto Shiro Hikichi Shiro Hikichi Yoshihiko Moro-oka Yoshihiko Moro-oka Synthesis and Structural Comparison of Tp<sup>iPr</sup><sub><sup>2</sup></sub>Rh[<i>cis</i>-1,2-bis(diphenylphosphino)ethene]:  Factors Determining Hapticity (κ<sup>2</sup> vs κ<sup>3</sup>) of the Tp<sup>iPr</sup><sub><sup>2</sup></sub> Ligand in Tp<sup>iPr</sup><sub><sup>2</sup></sub>Rh(diphosphine) Complexes American Chemical Society 2000 pendant pyrazolyl group spectroscopic features κ 2 steric repulsion Tp iPr 2 Ligand Structural Comparison Tp iPr 2 Rh Tp iPr 2 species RhP 2 X conformation κ 3 2000-08-05 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Synthesis_and_Structural_Comparison_of_Tp_sup_iPr_sup_sub_sup_2_sup_sub_Rh_i_cis_i_-1_2-bis_diphenylphosphino_ethene_Factors_Determining_Hapticity_sup_2_sup_vs_sup_3_sup_of_the_Tp_sup_iPr_sup_sub_sup_2_sup_sub_Ligand_in_Tp_sup_iPr_sup_sub_sup_2_sup_sub_Rh/3762870 Comparison of structural and spectroscopic features of the Rh(I)−diphosphine complexes Tp<sup>iPr</sup><sub><sup>2</sup></sub>Rh(Ph<sub>2</sub>P−X−PPh<sub>2</sub>) reveals that the dominant factor governing hapticity of the Tp<sup>iPr</sup><sub><sup>2</sup></sub> ligand (κ<sup>2</sup> vs κ<sup>3</sup>) is conformation of the central rhodadiphosphacycle. A folded RhP<sub>2</sub>X conformation hinders coordination of the pendant pyrazolyl group due to steric repulsion with the bridging part (X) in diphosphine to lead to a κ<sup>2</sup>-Tp<sup>iPr</sup><sub><sup>2</sup></sub> species, whereas κ<sup>3</sup>-coordination is found in complexes with a flat RhP<sub>2</sub>X conformation.