Bismuth−Arene π-Interaction: A Combined Experimental and Theoretical Approach

The triorgano bismuth compound [Bi(CH2C6H4Cl-2)3]2 (2) was characterized by an X-ray single-crystal structure analysis, which reveals the formation of a two-dimensional network as a result of bismuth−arene π-coordination and π−π-stacking interactions with distances of 3.659 Å (bismuth−arenecentroid) and 3.869 Å (arene centroids), respectively. In order to elucidate the nature of this bonding situation, a quantum mechanical study was carried out. Additionally, a detailed theoretical study on several model compounds of the type BiX3·C6H6 (X = H, Me, OH, OMe, F, Cl, Br) was carried out at the BSSE-corrected MP2/TZVP level of theory in order to develop a better understanding of the bismuth−arene coordination. The calculated bismuth−arene distances in the model compounds BiMe3·C6H6 (∼3.75 Å) and Bi(OMe)3·C6H6 (∼3.35 Å) compare well with experimental values for [Bi(CH2C6H4Cl-2)3]2 (2) and [Bi(OSiPh2tBu)3]2 (1) of 3.659 and 3.340 Å, respectively. Interaction energies for the model compounds range from 7 kJ/mol for BiMe3·C6H6 to 41 kJ/mol for BiBr3·C6H6.