Synthesis of Platinum(II) Phoshine Isocyanide Complexes and Study of Their Stability in Isomerization and Ligand Disproportionation Reactions

(Isocyano Group π‐Hole)⋅⋅⋅[d‐MII] Interactions of (Isocyanide)[MII] Complexes, in which Positively Charged Metal Centers (d8‐M=Pt, Pd) Act as Nucleophiles

“…The reaction of the palladium(II) and platinum(II) isocyanide complexes cis ‐[MCl 2 (CNXyl) 2 ] (M=Pd, 1 ; Pt, 2 ; Xyl=2,6‐Me 2 C 6 H 3 ) with two equivalents of 4,6‐diaminopyrimidine‐2(1 H )‐thione (DAPT) in MeCN at RT leads to the precipitation of orange or yellow amorphous solids, respectively, of trans ‐[M(CNXyl) 2 (DAPT) 2 ](Cl) 2 (M=Pd, [ 4 ]Cl 2 ; Pt, [ 5 ]Cl 2 ; Scheme , i ) from the reaction mixture.…”

“…The reactiono ft he palladium(II) and platinum(II) isocyanide complexes cis-[MCl 2 (CNXyl) 2 ]( M = Pd, 1; [9] Pt, 2; [10] These products exhibit quite poor solubility in the most commonlyu sed solvents, including boiling dimethyl sulfoxide. We attempted to increase the solubility of these compounds by counterion metathesis, whichc hanges a" large cation/small anion" to a" large cation/large anion"c ombination;t he latter combination should provide ab etter solubility of metal complexes.…”

“…Solvents, PdCl 2 , K 2 PtCl 4 , CNXyl, NaBF 4 , and 4,6‐diaminopyrimidine‐2(1 H )‐thione (DAPT; Aldrich) were obtained from commercial sources and used as received, whereas acetonitrile was purified by the conventional distillation over P 2 O 5 . The complexes cis ‐[MCl 2 (CNXyl) 2 ] were prepared by the reported procedures . IR spectra were recorded on a Shimadzu IRAffinity‐1S FTIR spectrometer (4000–400 cm −1 ) in KBr pellets.…”

“…Solvents, PdCl 2 ,K 2 PtCl 4 ,C NXyl, NaBF 4 ,a nd 4,6-diaminopyrimidine-2(1H)-thione (DAPT;A ldrich) were obtained from commercial sources and used as received, whereas acetonitrile was purified by the conventional distillation over P 2 O 5 .T he complexes cis-[MCl 2 (CNXyl) 2 ]w ere prepared by the reported procedures. [9,10] IR spectra were recorded on aShimadzu IRAffinity-1S FTIR spectrometer (4000-400 cm À1 )i nK Br pellets. Solid-state NMR spectroscopy was performed on aB ruker AvanceI II NMR 400 WB spectrometer operating at 9.4 T. The CP/MAS NMR spectra were acquired by using ad ouble-resonance 4mmM AS Bruker probe at ar esonance frequency of 162 MHz under 14 kHz MAS.…”

“…[4] If the cation···p interactions and metal···(p system) semicoordination are widespread and their nature reflects the interplay between an electrophilic metal center and an ucleophilic p system (Figure 1, top row), the ph···[M] contacts( bottom row) have no covalent analogues;t hey are nearly unique and are based on the reverse pattern of interactions between an electron-deficient phs ystem and nucleophilic, albeit positively charged, metal center. [2,3] Only very few examples of ph···[M] noncovalent linkages were reported for contacts between rather electron-rich d 10 -Au I , [5] d 8 -Pt II ,a nd d 8 -Pd II[6] metal centers and electron-deficient phd onor systems, such as fluorinated arenes. It is likely that only nucleophilic metal centers act as acceptor components of the ph···[M] interactions.…”