Synthesis and characterization of monomeric siloxo palladium(II) complexes: crystal structure of [Pd(tmeda)(C6F5)(OSiPh3)]

Arylpalladium Complexes with a Silsesquioxanate Ligand. Preparation and Structures in the Solid State and in Solution

“…The square-planar Pd(II) center is bonded to the chelating diamine ligand, a C 6 F 5 group, and an O atom from a silanol site of the silsesquioxane. The Pd−O bond length (2.000(2) Å) is within the range of the bonds reported for aryloxo−palladium complexes (1.979−2.129 Å) 9b-f and alkoxo−palladium complexes (2.020−2.134 Å) 8a,c and is slightly longer than that in the siloxopalladium complex [Pd(C 6 F 5 )(OSiPh 3 )(tmeda)] (1.986(3) Å), which may be ascribed to the high degree of electron-withdrawing character of the silsesquioxanate ligand compared with that of the OSiPh 3 ligand 2a. Pt complexes with silsesquioxanate or silanolate and phenyl ligands at trans positions, trans -[Pt{R 7 O 10 Si 7 (OH) 2 }(Ph)(PEt 3 ) 2 ] (R = c -C 5 H 9 , i -C 4 H 9 ) (Pt−O = 2.129(3), 2.113(2) Å) 6c and trans -[Pt{OSiMe 2 (C 6 H 4 CF 3 -4)}(Ph)(PPh 3 ) 2 ] (Pt−O = 2.091(4) Å), contain a Pt−O bond that is longer than the Pd−O bond of 4 , partly because of the trans influence of the phenyl ligands in the complexes being greater than that of the chelating tmeda ligand.…”

“…Recently, several research groups, including ours, identified Pt complexes with mono- and bidentate silsesquioxanate ligands . Although Pt and Pd complexes with O-bonded alkoxo , and aryloxo ligands have been widely investigated during the last few decades, the corresponding silanolate complexes having a M−O−Si bond (M = Pd, Pt) are much rarer. − These silsesquioxanate or silanolate complexes of Pd and Pt mostly contain phosphines as auxiliary ligands. In this paper, we present our results for the preparation, characterization, and dynamic behavior in solution of arylpalladium silsesquioxane complexes having chelating N-donor ligands.…”

Preparation and NMR Studies of Palladium Complexes with a Silsesquioxanate Ligand

“…The plane formed by Pd, O1, and Si1 atoms is also perpendicular to the coordination plane. The Pd−O1−Si1 bond angle (125.6(2)°) is smaller than those of 2b (133.0(1)°), [Pd(C 6 F 5 )(OSiPh 3 )(tmeda)] (136.9(2)°, 137.9(2)°), and silsesquioxanate platinum complexes 1 (130.2(2)°, 134.6(2)°) . The O1···O6 and O6···O9 distances of 4b (2.588(4) and 2.771(5) Å) indicate the presence of two intramolecular O···H−O hydrogen bonds, and the O6−H1 and O9−H2 bonds are oriented toward O1 and O6, respectively.…”

tert-Butoxytriphenylsilane

“…In the light of the impressive attainment in natural product synthesis, silyl ethers in addition proved to be an essential structural element in their role as commonly used protecting groups as they are applied for alcohol functionalities (Scheidt et al, 2002;Vintonyak & Maier, 2007). Aside from several known x-ray structures of triphenylsiloxy substituted transition metal complexes (Bindl et al, 2009;Johnson et al, 2000;Ruiz et al, 2004;Schweder et al, 1999;Schweder et al, 2006;Wolff von Gudenberg et al, 1994), there have also been reported some corresponding main group compounds (Apblett & Barron, 1993;Ferguson et al, 1996;Ferguson et al, 2005;Wojtczak et al, 1996) as well as palladium allyl species that contain triphenylsilyl ether subunits (Chen et al, 2008).…”

“…For the synthesis and structure of Ph 3 SiO-i-Pr, see: Wojtczak et al (1996). For selected transition-metal complexes containing Ph 3 SiO groups, see: Bindl et al (2009); Johnson et al (2000); Ruiz et al (2004);Schweder et al (1999);Schweder et al (2006); Wolff von Gudenberg et al (1994). For selected maingroup compounds containing Ph 3 SiO units, see: Apblett & Barron (1993); Chen et al (2008); Ferguson et al (1996Ferguson et al ( , 2005.…”