Slow Magnetic Relaxation in a Palladium-Gadolinium Complex Induced by Electron Density Donation from the Palladium Ion

David C Izuogu; Takefumi Yoshida; Haitao Zhang; Goulven Cosquer; Keiichi Katoh; Shuhei Ogata; Miki Hasegawa; Hiroyuki Nojiri; Marko Damjanović; Wolfgang Wernsdorfer; Tomoya Uruga; Toshiaki Ina; Brian K Breedlove; Masahiro Yamashita

doi:10.1002/chem.201800699

Slow Magnetic Relaxation in a Palladium-Gadolinium Complex Induced by Electron Density Donation from the Palladium Ion

Chemistry. 2018 Jul 2;24(37):9285-9294. doi: 10.1002/chem.201800699. Epub 2018 Jun 7.

Authors

David C Izuogu^{1

2

3}, Takefumi Yoshida^{1

4}, Haitao Zhang¹, Goulven Cosquer¹, Keiichi Katoh¹, Shuhei Ogata⁵, Miki Hasegawa⁵, Hiroyuki Nojiri⁶, Marko Damjanović⁷, Wolfgang Wernsdorfer^{7

8}, Tomoya Uruga⁹, Toshiaki Ina⁹, Brian K Breedlove¹, Masahiro Yamashita^{1

10

11}

Affiliations

¹ Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan.
² Department of Pure & Industrial Chemistry, University of Nigeria, Nsukka, 410001, Nigeria.
³ Department of Chemistry, University of Cambridge, Lensfield Rd., Cambridge, CB2 1EW, UK.
⁴ Electronic Functional Macromolecules Group, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan.
⁵ Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama-Gakuin University, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5258, Japan.
⁶ Institute for Materials Research, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
⁷ Physikalisches Institut and Institute of Nanotechnology, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany.
⁸ CNRS and Université Grenoble Alpes, Institut Néel, 38042, Grenoble, France.
⁹ Research & Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), 1-1-1 Kouto, Sayo, Hyogo, 679-5198, Japan.
¹⁰ WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, 980-8577, Japan.
¹¹ School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China.

PMID: 29663534
DOI: 10.1002/chem.201800699

Abstract

Incorporating palladium in the first coordination sphere of acetato-bridged lanthanoid complexes, [Pd₂ Ln₂ (H₂ O)₂ (AcO)₁₀ ]⋅2 AcOH (Ln=Gd (1), Y (2), Gd_0.4 Y_1.6 (3), Eu (4)), led to significant bonding interactions between the palladium and the lanthanoid ions, which were demonstrated by experimental and theoretical methods. We found that electron density was donated from the d⁸ Pd²⁺ ion to Gd³⁺ ion in 1 and 3, leading to the observed slow magnetic relaxation by using local orbital locator (LOL) and X-ray absorption near-edge structure (XANES) analysis. Field-induced dual slow magnetic relaxation was observed for 1 up to 20 K. Complex 3 and frozen aqueous and acetonitrile solutions of 1 showed only one relaxation peak, which confirms the role of intermolecular dipolar interactions in slowing the magnetic relaxation of 1. The slow magnetic relaxation occurred through a combination of Orbach and Direct processes with the highest pre-exponential factor (τ_o =0.06 s) reported so far for a gadolinium complex exhibiting slow magnetic relaxation. The results revealed that transition metal-lanthanoid (TM-Ln) axial interactions indeed could lead to new physical properties by affecting both the electronic and magnetic states of the compounds.

Keywords: computational techniques; electron density donation; electron-deficient; gadolinium; heterometallic; magnetism; metal-metal interactions; quantum dots; spectroscopic methods.