Ring expansion and N,N-dimethylformamide-solvation of the cyclodimeric complex bis(3-pyridyl)dimethylsilanedicholoropalladium(II)

Abstract

The reaction of (COD)PdCl 2 (COD = 1,5cyclooctadiene) with (3-Py) 2 SiMe 2 (bis(3-pyridyl)dimethylsilane) in acetone produces single crystals consisting of cyclodimers, [PdCl 2 ((3-Py) 2 SiMe 2 )] 2 , whereas the similar reaction in a mixture of dichloromethane and ethanol yields amorphous submicrospheres consisting of cyclotrimers, [PdCl 2 ((3-Py) 2 SiMe 2 )] 3 . In a boiling chloroform solution, the cyclodimers are completely converted to the cyclotrimers. The structures of both cyclic species are locked at temperatures below 0°C. The cyclotrimer equilibrates to the cyclodimer, the cyclotrimer, and cyclotrimeric mono-DMF adduct, [Pd 3 Cl 5 (DMF)((3-Py) 2 SiMe 2 ) 3 ]Cl in the mole ratio of 6:1:5 in DMF solution at room temperature. The cyclodimer finally reaches the equilibrium in the same condition. ExperimentalPalladium(II) chloride, 1,5-cyclooctadiene (COD), and dichlorodimethylsilane were purchased from Aldrich, and used without further purification. (COD)PdCl 2 [30] and bis(3-pyridyl)dimethylsilane((3-Py) 2 SiMe 2 ) [31] were Electronic supplementary material The online version of this article (

Formation, Expansion, and Interconversion of Metallarings in a Sulfur‐Bridged AuICoIII Coordination System

“…Remarkably, 3 2+ is readily interconvertible with a nine‐membered Au I 2 Co III ring in [Au 2 Co(dppe)( D ‐nmp) 2 ] + ( 4 + ) in solution; this process depends on several external factors, such as solvent, concentration, and counteranion. To the best of our knowledge, such an interconversion between heteroleptic and heterometallic rings is unprecedented, although several examples of the interconversion of homoleptic and homometallic rings have been reported 5a,f,g. The interconversion between 3 2+ and 4 + , together with the conversion of 2 into 3 2+ , confirms the lability of the AuS and AuP bonds, which is essential for the observed metallaring expansion and contraction events.…”