Palladium(ii) complexes of N,N-diphenylacetamide based thio/selenoethers and flower shaped Pd 16 S 7 and prismatic Pd 17 Se 15 nano-particles tailored as catalysts for C-C and C-O coupling.

2-Bromo-N,N-diphenylacetamide (P1) prepared by reacting diphenylamine with α-bromoacetyl bromide, on treatment with Na2 S and Na2 Se generated in situ, has resulted in thio and selenoether ligands, L1 ((Ph2 NCOCH2 )2 S) and L2 ((Ph2 NCOCH2 )2 Se), respectively. Reacting these ligands with Na2 PdCl4 in ethanol at room temperature resulted in their complexes [Pd(L1/L2)2 Cl2 ] (C1/C2). P1, L1, L2, C1 and C2 were characterized by1 H,13 C{1 H} and77 Se{1 H} NMR spectroscopy, IR spectroscopy and High resolution mass spectrometry (HR-MS). Single crystal structures of all the five compounds were determined by X-ray diffraction. In both C1 and C2 the geometry of Pd is nearly square planar. Flower shaped Pd16 S7 (size 26-50 nm) and prismatic Pd17 Se15 NPs (size 20-55 nm) were synthesized by a single source precursor route (thermolysis at ∼280 °C in trioctylphosphine) from air and moisture insensitive C1 and C2, respectively. These shapes of the two nanophases were unknown hitherto. They were characterized by powder X-ray diffraction (PXRD), SEM-EDX and HR-TEM and found to show good catalytic activity for Suzuki-Miyaura (Pd loading 0.5 mol%; yield up to 96%) and C-O (Pd loading 0.5 mol%; yield up to 96%) coupling reactions (at 100 °C) of aryl bromides with phenylboronic acid and phenol, respectively. The complexes C1 and C2 were found very efficient for Suzuki-Miyaura and C-O coupling as revealed by their optimum loading of 0.0001-0.01 and 0.1 mol% of Pd, respectively, for the two reactions. The reuse of the complexes or NPs as a catalyst is demonstrated.