1258560-03-0Relevant articles and documents
Unusually large bite angle of a distally diphosphanylated calix[4]arene chelator
Sameni, Soheila,Jeunesse, Catherine,Awada, Mouhamad,Matt, Dominique,Welter, Richard
, p. 4917 - 4923 (2011/02/28)
5,17-Diphenylphosphanyl-11,23-bis(4-tolyl)-25,26,27,28-tetrapropoxycalix[4] arene (6), a semi-rigid, calixarene-based diphosphane in which the phosphorus atoms are separated by 12 chemical bonds, reacts with [Ni(η5- C5H5)(1,5-cyclooctadiene)]BF4 or AgBF 4 to afford the corresponding chelate complexes [Ni(η 5-C5H5)(6)]BF4 and [Ag(6)]BF 4 quantitatively. These complexes were both characterised by a single-crystal X-ray diffraction study. In the nickel complex the ligand shows a bite angle of 104.5°, which lies in the range expected for this kind of diphosphane with a large P???P separation. In the silver(I) complex the diphosphane displays a much larger bite angle of 138.8°, which was unexpected and reflects the flexilibilty of the calix[4]arene skeleton. Furthermore, in solution the silver complex shows dynamic behaviour. One of the observed motions corresponds to the silver atom switching reversibly from a linear to a bent AgP2 cordination geometry. An upper-rim, distally diphosphanylated calix[4]arene readily forms a complex with AgBF4. In the solid state the ligand displays an unexpectedly large bite angle of 138.8°, which reflects the flexibility of the calixarene skeleton. In solution the silver atom moves rapidly between two positions lying on either side of the calixarene axis.
