Synthesis of Pt(II) phosphinocarboxylate complexes with auxiliary arylcarbene ligands and factors that control their stereochemistry
Abstrakt
Orthoplatinated complexes [Pt(C^C*)(acac)] (1 (R)), in which CC* is orthoplatinated 3-R-1-phenyl-1H-benzo[d]imidazol-2-ylidene and R = Me and Ph, reacted with 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) under protonation of the acetylacetonate ligand (acac) to produce the corresponding phosphinocarboxylate bischelate complexes [Pt(C^C*)(dpf-kappa O-2,P)] (2(R)) as single isomers with trans-P,C(carbene) geometry. The compounds were fully characterized by elemental analysis, spectroscopic methods, single-crystal X-ray diffraction analysis, and cyclic voltammetry.
In addition, DFT calculations were used to determine differences in energy and the bonding situation between 2(R) and the hypothetical geometric isomers 3(R) with a trans-P,C(phenyl) arrangement. The experimental and theoretical results are consistent with the antisymbiosis effect observed in complexes of soft metal ions, namely with weakening of Pt-C bonds by strongly trans-influencing ligands.