Synthesis and Characterization of Pt(II) and Pd(II) Complexes with Planar Aromatic Oximes

A series of four Werner-type complexes Pd(II) and Pt(II) with planar, isomeric conjugated aromatic naphtoquinone oximes were synthesized for the first time. These ligands 1-oxime-2-naphtoquinone (HL1) 2-oxime-1-napthoquinone (HL2). Compounds characterized using thermal analysis, spectroscopic methods, X-ray analysis. TG/DSC data collected pure starting organic ligands, their complexes, indicated vigorous exothermic decomposition at ~155 °C HL ~350 transition metal complexes. Crystal structures two Pt compounds 2-oxime-1-quinone determined revealed formation cis-geometry incorporation molecules stoichiometric solvents in lattice: acetonitrile nitrobenzene. Both crystallization displayed attractive interactions between C-H groups oxygen atoms nitroso leading to short distances those fragments. Despite presence inclusion, overall structure motifs both represent 1D columnar coordination polymer, which PtL2 units are held together via metallophilic interactions, thereby forming ‘Pt-wires’. The Hirshfield surface analysis was performed crystallographically results showed intermolecular π–π stacking Pt–Pt among planar In addition, also verified hydrogen bonding platinum unit solvent molecules. Solid bulk powdery samples PtL12 PtL22 demonstrated pronounced photoluminescence near infrared region spectrum ~980 nm, being excited range 750–800 nm. NIR emission observed only Pt-complexes not or Pd-complexes. Additionally, Pt-naphtoquinone do show luminescence solutions, suggests importance a ‘metal wire’ this process.