A magnetic and conductive study on a stable defective extended cobalt atom chain
Journal
Dalton Transactions
Journal Volume
43
Journal Issue
16
Pages
6229-6235
Date Issued
2014
Author(s)
Wang, W.-Z. et al.
Wu, Y.
Ismayilov, R.H.
Kuo, J.-H.
Yeh, C.-Y.
Lee, H.-W.
Fu, M.-D.
Lee, G.-H.
Peng, Shie-Ming
Abstract
Two pentacobalt(II) EMACs were synthesized. A pyrazine-modulated tripyridyldiamine resulted in an EMAC with fully delocalized Co-Co bonds along molecules. From a pyrazine- and naphthyridine-containing ligand, a defective cobalt linear EMAC with an 8-coordinated cobalt(II) in the center was obtained for the first time. An electrochemistry study on the defective pentacobalt chain compound showed redox peaks at E1/2 = -1.00, +0.76, and +0.98 V (versus EAg/AgCl), indicating that it is quite stable and very resistant to both oxidation and reduction. Research on magnetism revealed that the fully delocalized Co EMAC is a spin mixture, and the defective cobalt EMAC showed a high-spin mononuclear cobalt(II) behaviour with a magnetic moment of 2.63 μB per molecule at room temperature. Measurement on molecular electric conductance by STM bj showed a single-molecular resistance of 15.4 (± 3.1) MΩ for defective and 12.3 (± 2.6) MΩ for delocalized pentacobalt complexes.
Type
journal article