1031438-36-4Relevant articles and documents
Structure and properties of the macrocyclic tridentate ferrocenylphosphine ligand (-PhPC5H4-)3
Mizuta, Tsutomu,Aotani, Tomoyuki,Imamura, Yuki,Kubo, Kazuyuki,Miyoshi, Katsuhiko
, p. 2457 - 2463 (2008)
Isolation and characterization were carried out for a novel tridentate ferrocenylphosphine macrocycle, (-PhPC5H4FeC 5H4-)3, as follows. A photolytic ring-opening reaction of PPh-bridged [1]ferrocenophane in ether gave a mixture of its oligomers. After their sulfurization, GPC separation of low-molecular-weight species afforded two isomers of a macrocyclic trimer, 1,1″:1′,1: 1?,1-tris(phenylthiophos-phinidene)tris(ferrocene), in which three 1,1′-ferrocenediyl units and three P(S)Ph groups were alternately linked to form a macrocyclic ring. Although yields of both isomers were low (17% in total), they were successfully desulfurized in good yields without configurational inversion at their phosphorus centers by treatment with MeOTf/P(NMe2)3 (OTf = CF3SO3), to give the respective tridentate macrocyclic phosphine ligands. The molecular structure of one isomer (C3 isomer) with C3 symmetry was determined by X-ray analysis, while the other was identified as the C s isomer on the basis of 1H, 13C, and 31P NMR data. When the C3 isomer was heated in toluene at around 80°C, it isomerized gradually but almost completely to the C s isomer with the activation energy ΔG350 double barred pipe = 26.2 ±0.6 kcal mol-1. The reaction of AgOTf with the C3 isomer in CH2Cl2 gave a mononuclear silver complex in which the C3 isomer encircled the Ag+ ion as a tridentate ligand. To our surprise, a similar reaction using the Cs isomer gave the same silver complex as above, indicating that a facile conversion of the Cs isomer to the C 3 isomer took place upon coordination to the Ag+ ion at room temperature.
