| Abstract
| - The reactions of chlorobridged cyclometalated complexes [Pd(C−N)(μ-Cl)]2 (C−N =orthometalated N,N-dimethylbenzylamine, dmba; 2-(para-tolyl)pyridine, p-tolpy; azobenzene,azb; N,N-dimethyl-1-naphthylamine, dmna; and 2-benzylpyridine, bzpy) with Li(Fmes) (Fmes= 2,4,6-tris(trifluoromethyl)phenyl or nonafluoromesityl) give, after hydrolysis, neutral aquocomplexes [Pd(C−N)(Fmes)(OH2)], where the ipso carbon atoms of the Fmes and thecyclometalated ligand are coordinated cis, as shown by an X-ray diffraction study of [Pd(dmba)(Fmes)(OH2)]. The aquo ligand is readily displaced by other ligands, giving complexes[Pd(C−N)(Fmes)L] (L = PPh3, 2,6-lutidine, NH3, CNtBu, CO) when monodentate ligandsare employed or [Pd(dmba-C)(Fmes)(2,2‘-bipy)], which contains a chelating 2,2‘-bipyridyland a monodentate C-bonded dmba. Different processes in solution are detected for thecomplexes containing the bulkier ligands: ligand rotation in the complex with PPh3; inversionof the bipy ligand in [Pd(dmba-C)(Fmes)(2,2‘-bipy)]; and equilibria with residual water inthe solutions of [Pd(C−N)(Fmes)(lut)] and [Pd(dmba-C)(Fmes)(2,2‘-bipy)].
- The neutral organometallic aquo complexes [Pd(C−N)(Fmes)(OH2)] (Fmes = 2,4,6-tris(trifluoromethyl)phenyl) are remarkably stable, considering that a hard water molecule is attached to a very soft Pd center. For bulky ligands the complexes [Pd(C−N)(Fmes)L] are in equilibrium with [Pd(C−N)(Fmes)(OH2)] formed with residual water in the solution.
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