Directed Positioning of Organometallic Fragments Inside a Calix[4]arene Cavity

Trans-chelating diphosphines, the elusive ligands!

“…We will focus on the ones containing two phosphine moieties tethered in distal positions as they are supposed to favour the trans-chelation, and after complexation, position the metal center at the center of the cavity entrance [121][122][123][124][125][126][127][128][129]. Lower rim bifunctionalized calix [4]arenes offer the additional advantage that there are two further sites where other groups can be easily appended to assist in the coordination (and/or catalysis).…”

Coordination and Organometallic Polymers and Oligomers of Upper-Rim Functionalized Calix[4]arenes by Transition Metals

“…Indeed, Takenaka et al recently reported the synthesis and the X-ray structure of a dimer complex, 22, formulated as [dichloro(5,17-bis(diphenylphosphino)-25,26,27,28-benzoxycalix [4]arene)palladium (II)] [22]. This result contrasts the findings for other square planar complexes of 1,3-diphosphinated calix [4]arenes, including the dicholoplatinum(II) analogue, which is a monomeric species [23,24]. …”

Influence des propriétés intrinsèques de ligands calixaréniques sur des réactions de transformation catalytique de l'éthylène

“…Les calixarènes 1 et 2 [7] contiennent deux groupements diphénylphosphanyle greffés sur des positions para-phénoliques distales. Ces phosphines sont thermiquement très robustes.…”