A paramagnetic trigonal paddlewheel complex with iron-dithiolato ligand paddles: {[(C9H18N2S2)Fe(NO)](3)Ag-2}(BF4)(2) Academic Article uri icon


  • Addition of AgBF4 to (bme-dach)Fe(NO), (bme-dach, N,N-bis(2-mercapto-ethyl)-1,4-diazacycloheptane) affords a pentametallic C3 paddlewheel complex, {[(bme-dach)Fe(NO)]3Ag2}[BF4]2, resulting from the ability of the thiolate sulfurs of the N2S2 complex to serve as a bidentate bridging ligand to Ag+ ions. Single crystal X-ray analysis reveals the NO ligands coordinated to each Fe are all pointed in the same direction, resulting in a threefold rotation axis and a pseudo-mirror plane bisecting the AgAg axis in the asymmetric unit cell. This Ag2 trigonal paddlewheel complex of non-bonded AgAg average distance = 2.866(3) has also been characterized by infrared and UV-vis spectroscopies. The complex shows paramagnetism both in solution (Evans' method) and in the solid state due to three S = 1/2 {Fe(NO)}7 units. The EPR spectrum shows a single isotropic signal with g = 2.024. SQUID analysis confirms this paramagnetism yielding a T value of 1.17 emu-K/mol with the presence of weak ferromagnetic coupling evident at temperatures less than 20 K. To our knowledge this is the first example of a paddlewheel complex in which paramagnetism exists within the bridging bidentate ligand "paddles". 2008 Elsevier B.V. All rights reserved.

published proceedings


author list (cited authors)

  • Hess, J. L., Young, M. D., Murillo, C. A., & Darensbourg, M. Y.

citation count

  • 8

complete list of authors

  • Hess, Jennifer L||Young, Mark D||Murillo, Carlos A||Darensbourg, Marcetta Y

publication date

  • November 2008