Synthesis, catalytic activity, and photophysical properties of 5,6-membered Pd and Pt SCS'-pincer complexes based on thiophosphorylated 3-amino(hydroxy)benzoic acid thioanilides.

Novel unsymmetrical SCS'-pincer ligands, 1-[PhNHC(S)]-3-[Ph(2)P(S)NH]-C(6)H(4) (3) and 1-[PhNHC(S)]-3-[Ph(2)P(S)O]C(6)H(4) (7), bearing a thiocarbamoyl moiety in combination with thiophosphorylamino- and thiophosphoryloxy-donating groups, respectively, were obtained via thiophosphorylation of 3-amino- and 3-hydroxy-benzoic acid (thio)anilides 1 and 6. Direct cyclometallation of the central benzene ring in the ligands 3 and 7 in reaction with (PhCN)(2)MCl(2) (M = Pd, Pt) as a metal precursor afforded κ(3)-SCS'-hybrid pincer complexes 8, 9 with 5- and 6-membered fused metallacycles in good to high yields (67-95%). The complexes 8 and 9 were characterized by multinuclear NMR ((31)P, (1)H, (13)C) and IR spectroscopy as well as single-crystal X-ray crystallography. Palladium complexes 8a and 9a were shown to be active catalysts for the Suzuki-Miyaura cross-coupling reaction. In the solid state the ligands 3 and 7 as well as their Pt(II) and Pd(II) complexes 8 and 9 are luminescent at 300 K. The emission of the complexes has the different origin depending on the metal nature.

5,6-Membered palladium pincer complexes of 1-thiophosphoryloxy-3-thiophosphorylbenzenes. Synthesis, X-ray structure, and catalytic activity.

Novel unsymmetrical ligands, 1-thiophosphoryloxy-3-thiophosphorylbenzenes 3a-d, bearing phosphine sulfide and thiophosphoryloxy moieties as coordinating sites, were found to undergo cyclometalation at the C-2 position of the central benzene ring in a reaction with bis(benzonitrile)palladium dichloride affording rare examples of nonsymmetrical pincer complexes, namely [2-{(thiophosphoryl)oxy}-6-(diphenylthiophosphoryl)phenyl]palladium chlorides 4a-d, containing 5- and 6-membered fused metallacycles with kappa3-SCS'-coordination. Molecular structures of the complexes were characterized by X-ray diffraction. These complexes demonstrated high catalytic activity for the Suzuki cross-coupling reactions of aryl bromides with phenylboronic acid.