Binuclear organoplatinum(II) complexes with double bis(diphenylphosphino)acetylene bridges: Synthesis, X-ray structure determination, electronic structures and DFT calculations

Abstract

The organoplatinum complexes cis-[PtAr 2 (SMe 2 ) 2 ] (Ar = p-MeC 6 H 4 and p-MeOC 6 H 4 ) and cis,cis-[Me 2 Pt(µ-SMe 2 ) 2 PtMe 2 ] react very easily -in acetone at room temperature -with 1 or 2 equiv 1,1'-bis(diphenylphosphino)acetylene (= dppac), to give the diplatinum(II)6 H 4 ; 3, R = p-MeOC 6 H 4 ) in which two square-planar R 2 Pt units are held together by two bridging dppac ligands. All the complexes were characterized using multinuclear ( 1 H, 31 P and 195 Pt) NMR spectroscopy and single crystal X-ray structure determination. Investigation of electronic structures and related DFT and TD-DFT calculations supported a mixed 1 IL (intraligand charge transfer)/ 1 MLCT (metal-to-ligand charge transfer) for R=Me and L´LCT (ligand-to-ligand charge transfer) for R= p-MeC 6 H 4 and p-MeOC 6 H 4 .

Chelating and Bridging Roles of 2-(2-Pyridyl)benzimidazole and Bis(diphenylphosphino)acetylene in Stabilizing a Cyclic Tetranuclear Platinum(II) Complex

“…Therefore, the structure of complex 2 confirms that "Pt(μpbz)Pt" moieties are connected through dppac bridging ligand It should be noted that this kind of bridged dppac complex where a dppac molecule acts as a bridging ligand between two metal fragments is not common. 3,67,68 ESI-MS result further confirms the molecular formulas formation by demonstrated isotopically well-resolved peak at m/z = 2107.4 which is related to [2 + H 3 O] + . The peak matched well with its calculated theoretical isotope distributions (see Figure 3).…”

“…The terminal Me ligands are trans in relation to each other. It should be noted that this kind of bridged dppac complex where a dppac molecule acts as a bridging ligand between two metal fragments is not common. ,, …”

“…The construction of multinuclear metal assemblies has been a growing area of research during the past decade. , Developments based on the use of different ligands as the building unit for the synthesis of compounds have been reported for binuclear Pt complexes, − although to the best of our knowledge, tetranuclear complexes are rare. − …”

Which is the Stronger Nucleophile, Platinum or Nitrogen in Rollover Cycloplatinated(II) Complexes?

“…All the chemical shifts and coupling constants are in ppm and Hz, respectively. The compounds 1-methyl-4-(2′-pyridyl)­pyridinum iodide (abbreviated as Me-2,4′-bpy-I), and [Pt 2 Me 4 (μ-SMe 2 ) 2 ] were prepared as reported.…”

Kinetic Studies of Oxidative Addition Reaction of Arylplatinum(II) Complex Containing 4,4′‐Bipyridine and Calculation of Activation Parameters

“…Such complexes can in turn be used as building blocks for multimetallic systems . Thus, designing of new multinuclear complexes containing bridging ligands has received much more attention due to their potential applications in catalysis, electrical conductivity, and photoactive devices . Pt(II) complexes with ligands containing nitrogen, phosphorus, and sulfur have attracted great interest because of their antitumor activity .…”