Synthesis and electrochemistry of niobium complexes incorporating asymmetrically substituted ansa-ligands
摘要:
The following asymmetric ansa-niobocene(IV) dichloride complexes have been prepared: [Nb{Me2Si(eta(5)-C5Me4)(eta(5)-C5H3R)}Cl-2] (R = H (1a), Me (2a), SiMe3 (3a), Pr-i (4a), PPh2 (5a)). The ESR spectra of 1a-5a have been recorded. Oxidation and reduction potentials have also been measured and compared with nonansa-niobocene complexes. The new niobocene complexes [Nb(eta(5)-C5H4R)(2)}Cl-2] ;(R = Pr-i (6a), PPh2 (7a)) have been also synthesized. In addition, reduction of 1a in the presence of ligand (RCdropCR) (R=Me, Ph) to give [Nb{Me2Si(eta(5)-C5Me4)(eta(5)-C5H4)}Cl(RCdropCR)] (R=Me (8a), Ph (9a)) is described. (C) 2002 Elsevier Science B.V. All rights reserved.
Synthesis and electrochemistry of niobium complexes incorporating asymmetrically substituted ansa-ligands
摘要:
The following asymmetric ansa-niobocene(IV) dichloride complexes have been prepared: [Nb{Me2Si(eta(5)-C5Me4)(eta(5)-C5H3R)}Cl-2] (R = H (1a), Me (2a), SiMe3 (3a), Pr-i (4a), PPh2 (5a)). The ESR spectra of 1a-5a have been recorded. Oxidation and reduction potentials have also been measured and compared with nonansa-niobocene complexes. The new niobocene complexes [Nb(eta(5)-C5H4R)(2)}Cl-2] ;(R = Pr-i (6a), PPh2 (7a)) have been also synthesized. In addition, reduction of 1a in the presence of ligand (RCdropCR) (R=Me, Ph) to give [Nb{Me2Si(eta(5)-C5Me4)(eta(5)-C5H4)}Cl(RCdropCR)] (R=Me (8a), Ph (9a)) is described. (C) 2002 Elsevier Science B.V. All rights reserved.