Formation, Characterization, and Bonding of cis - and trans -[PtCl 2 {Te(CH 2 ) 6 } 2 ], cis-trans -[Pt 3 Cl 6 {Te(CH 2 ) 6 } 4 ], and cis - trans -[Pt 4 Cl 8 {Te(CH 2 ) 6 } 4 ]: Experimental and DFT Study.

[PtCl 2 {Te(CH 2 ) 6 } 2 ] ( 1 ) was synthesized from the cyclic telluroether Te(CH 2 ) 6 and cis -[PtCl 2 (NCPh) 2 ] in dichloromethane at room temperature under the exclusion of light. The crystal structure determination showed that in the solid state, 1 crystallizes as yellow plate-like crystals of the cis -isomer 1 cis and the orange-red interwoven needles of 1 trans . The crystals could be separated under the microscope. NMR experiments showed that upon dissolution of the crystals of 1 cis in CDCl 3 , it isomerizes and forms a dynamic equilibrium with the trans -isomer 1 trans that becomes the predominant species. Small amounts of cis-trans -[Pt 3 Cl 6 {Te(CH 2 ) 6 } 4 ] ( 2 ) and cis - trans -[Pt 4 Cl 8 {Te(CH 2 ) 6 } 4 ] ( 3 ) were also formed and structurally characterized. Both compounds show rare bridging telluroether ligands and two different platinum coordination environments, one exhibiting a cis -Cl/ cis -Te(CH 2 ) 6 arrangement and the other a trans -Cl/ trans -Te(CH 2 ) 6 arrangement. Complex 2 has an open structure with two terminal and two bridging telluroether ligands, whereas complex 3 has a cyclic structure with four Te(CH 2 ) 6 bridging ligands. The bonding and formation of the complexes have been discussed through the use of DFT calculations combined with QTAIM analysis. The recrystallization of the mixture of the 1:1 reaction from d 6 -DMSO afforded [PtCl 2 {S(O)(CD 3 ) 2 }{Te(CH 2 ) 6 }] ( 4 ) that could also be characterized both structurally and spectroscopically.