Structure and Properties of the Macrocyclic Tridentate Ferrocenylphosphine Ligand (−PhPC5H4FeC5H4−)3
详细信息 查看全文
- 作者：Tsutomu Mizuta ; Tomoyuki Aotani ; Yuki Imamura ; Kazuyuki Kubo ; Katsuhiko Miyoshi
- 刊名：Organometallics
- 出版年：2008
- 出版时间：June 9, 2008
- 年：2008
- 卷：27
- 期：11
- 页码：2457 - 2463
- 全文大小：154K
- 年卷期：v.27,no.11(June 9, 2008)
- ISSN：1520-6041
文摘
Isolation and characterization were carried out for a novel tridentate ferrocenylphosphine macrocycle, (−PhPC5H4FeC5H4−)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(phenylthiophosphinidene)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 Cs 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 Cs isomer with the activation energy ΔG350
= 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 C3 isomer took place upon coordination to the Ag+ ion at room temperature.
= 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 C3 isomer took place upon coordination to the Ag+ ion at room temperature.