Palladium(ii) complexes of N,N-diphenylacetamide based thio/selenoethers and flower shaped Pd16S7 and prismatic Pd17Se15 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 Na₂S and Na₂Se generated in situ, has resulted in thio and selenoether ligands, L1 ((Ph₂NCOCH₂)₂S) and L2 ((Ph₂NCOCH₂)₂Se), respectively. Reacting these ligands with Na₂PdCl₄ in ethanol at room temperature resulted in their complexes [Pd(L1/L2)₂Cl₂] (C1/C2). P1, L1, L2, C1 and C2 were characterized by ¹H, ¹³C{¹H} and ⁷⁷Se{¹H} 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 Pd₁₆S₇ (size 26-50 nm) and prismatic Pd₁₇Se₁₅ 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.