[PdCl2(dppfO2-O,O′)]: a simple palladium(II) complex with a rare tetrahedral structure

Abstract

Single-crystal X-ray diffraction analysis of PdCl 2 (dppfO 2 ) [dppfO 2 = 1,1A-bis(oxodiphenylphosphoranyl)ferrocene] shows a rare tetrahedral geometry at a d 8 metal centre; physical and spectroscopic characterisations indicate a paramagnetic species.

Palladium (II) complexes with mono-oxide 1,1′-bis(diphenylphosphino)metallocene ligands [Fe(η5-C5Me4PPh2)(η5-C5Me4P{O}Ph2)] and [Os(η5-C5H4PPh2)(η5-C5H4P{O}Ph2)]

“…The palladium atom in 3 is coordinated with two terminal chlorides, phosphorus and oxygen (the Pd-O length is 1.998(9) Å ) to give slightly distorted squareplanar configuration. The P@O bond (1.479(9) Å ) is slightly smaller than that for the coordinated (the length of the P@O bond in [{Fe(g 5 -C 5 H 4 P{O}Ph 2 ) 2 }PdCl 2 ] is 1.495 Å [3]) and even the uncoordinated phosphinoxide group (the P@O length in 4 is 1.495(7) Å ). The angle P(1)-O(1)-Pd(1) is 171°and significantly larger than the analogous angle for [{Fe(g 5 -C 5 H 4 P{O}Ph 2 ) 2 }PdCl 2 ] (158.3°) [3] and [{Fe(g 5 -C 5 H 4 PPh 2 )(g 5 -C 5 H 4 P{O}Ph 2 )}-W(CO) 3 I] (160.2°) [7].…”

“…The P@O bond (1.479(9) Å ) is slightly smaller than that for the coordinated (the length of the P@O bond in [{Fe(g 5 -C 5 H 4 P{O}Ph 2 ) 2 }PdCl 2 ] is 1.495 Å [3]) and even the uncoordinated phosphinoxide group (the P@O length in 4 is 1.495(7) Å ). The angle P(1)-O(1)-Pd(1) is 171°and significantly larger than the analogous angle for [{Fe(g 5 -C 5 H 4 P{O}Ph 2 ) 2 }PdCl 2 ] (158.3°) [3] and [{Fe(g 5 -C 5 H 4 PPh 2 )(g 5 -C 5 H 4 P{O}Ph 2 )}-W(CO) 3 I] (160.2°) [7]. The coordination of the palladium to the oxygen of the phosphinoxide group occurred in expense of strong distortion of the ferrocene moiety.…”

“…However the equimolar interaction of [Fe(g 5 -C 5 H 4 PPh 2 )(g 5 -C 5 H 4 P{O}Ph 2 )]-(dppfO) with palladium salts to form the P,O-chelated palladium complex has not been reported yet. Though the chelate palladium complex can be obtained from the corresponding dioxide [Fe(g 5 -C 5 H 4 P{O}Ph 2 ) 2 ] [3]. Attempts to synthesize the dicationic palladium complex by treating [(dppfO) 2 PdCl 2 ] with silver salts resulted in the mixture of unidentified products [2a].…”

Coordination Polymers of Palladium Bridged by Carboxylate and Dimethylaminoalkylselenolate Ligands

“…A Pd−Se bond distance of about 2.61 Å is observed in Pd 0 cluster compound {W 3 PdSe 4 } 2 8+ . Although a large deviation from planar geometry is mostly unexpected and uncommon as well for d 8 M II systems, few examples of significant distortion have been reported in the Cambridge Structural Database, and in fact a tetrahedral structure for Pd II (e.g., [PdCl 2 (dppfO 2 ‐ O,O′ )] (dppfO 2 =1,1′‐bis(oxodiphenylphosphoranyl)ferrocene)) is also known . The geometry around palladium in the case of Pd5 atom appears distorted linear (<O6‐Pd5‐Se3≈150°) and the metal center is stabilized by two reasonably strong interactions from Se (Pd5⋅⋅⋅Se2 i : 2.89 Å) and O (Pd5⋅⋅⋅O7: 2.56 Å) atoms of the triflate anion.…”

A Convenient and Selective Palladium‐Catalyzed Aerobic Oxidation of Alcohols

“…For example, Grushin and co‐workers reported firm evidence for the reversible Pd–O interaction of bidentate phosphine–phosphinoxide ligands 10. In addition, the oxidized dppf(O) 2 ligand (dppf=1,1′‐bis(diphenylphosphino)ferrocene) acts as an [O,O]‐chelating ligand and forms the stable palladium complex [PdCl 2 (dppfO 2 )] as shown by X‐ray structure analysis 11. Moreover, TPOs were used as co‐catalysts in Pauson–Khand reactions,12 and to facilitate crystallizations 13…”