Thiopyridazine-Based Palladium and Platinum Boratrane Complexes

• Published in: Inorganic chemistry Vol. 57; no. 12; pp. 6921 - 6931
• Main Authors: Holler, Stefan, Tüchler, Michael, Steller, Beate G, Belaj, Ferdinand, Veiros, Luis F, Kirchner, Karl, Mösch-Zanetti, Nadia C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 18.06.2018
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.8b00530

Palladium and platinum boratrane complexes of the type [M­{B­(PnMe,tBu)3}­(PPh3)] (M = Pd 1, Pt 2b) have been prepared via the reaction of the soft scorpionate ligand potassium tris­(4-methyl-6-tert-butyl-3-thiopyridazinyl)­borate KTnMe,tBu with bis­(triphenylphosphine)­metal­(II) dichloride. While reaction with the Pd precursor allowed direct isolation of a symmetric boratrane complex, the Pt analogue led to the hydrido compound [Pt­{B­(PnMe,tBu)3}­(PPh3)­H]Cl (2a), which after reaction with a base gave 2b. Subsequent oxidation with Br2 and I2, respectively, led to the dihalide compounds of the molecular formula [M­{B­(PnMe,tBu)3}­X2] (3a,b–4a,b). Halide abstraction with Ag­(SbF6) further gave interesting cationic compounds of either dimeric [Pd­{B­(PnMe,tBu)3}­X]2(SbF6)2 (5a,b) or monomeric [Pd­{B­(PnMe,tBu)3}­(NCMe)2]­(SbF6) (6) nature. All compounds were spectroscopically and X-ray crystallographically characterized revealing strong metal to boron interactions. DFT calculations of 1, 2a, and 2b confirm the strong M–B interaction and a high positive charge on the metal centers.