Chemical Papers

, Volume 72, Issue 4, pp 841–851 | Cite as

Synthesis, structure, and properties of a lantern-type dinuclear rhodium(II) complex cis-[Rh2(4-Me-pf)2(O2CCMe3)2], 4-Me-pf = N,N′-di-p-tolylformamidinate anion

  • Makoto Handa
  • Satoshi Nishiura
  • Takafumi Masuda
  • Natsumi Yano
  • Masahiro Mikuriya
  • Yusuke Kataoka
Original Paper


A lantern-type dinuclear complex cis-[Rh2(4-Me-pf)2(O2CCF3)2] (1) (4-Me-pf = N,N′-di-p-tolylformamidinate anion) was reacted with an excess of pivalic acid in an aqueous NaOH solution with CHCl3/MeOH (1:3 vol./vol.) at room temperature for 24 h with stirring to give cis-[Rh2(4-Me-pf)2(O2CCMe3)2] (2). A single crystal obtained by recrystallization of 1 from an acetonitrile solution was employed for X-ray crystal structure analysis. The analysis showed that the obtained complex was a cis-[Rh2(4-Me-pf)2(O2CCMe3)2(MeCN)2] (2(MeCN)2) with a lantern-type dinuclear structure and a cis-(2:2) arrangement of the two formamidinato and two carboxylato ligands around the dirhodium(II) core, similar to the previously reported crystal structures for 1(H2O)2·0.5C6H6 and 1(MeCN)2. Complex 2 showed absorption bands at 613, 506, 435, and 344 nm in MeCN, while complex 1 showed the bands at 516, 460, and 326 nm in MeCN. All the bands observed for 1 and 2 were reasonably assigned using time-dependent density functional theory calculation. Moreover, it was confirmed that the electron-donating t-butyl groups on the carboxylato bridges of 2 give rise to negative shifts in the redox potentials (E 1/2 = 0.32 and 1.22 V (vs. SCE) in CH2Cl2) for Rh 2 II,II /Rh 2 II,III and Rh 2 II,III /Rh 2 III,III processes relative to those of 1 (E 1/2 = 0.71 and 1.47 V (vs. SCE) in CH2Cl2) that has electron-withdrawing fluorine groups on the carboxylate bridges.


Lantern-type dirhodium(II) complex Formamidinate Pivalate Mixed-ligand complex UV–Vis spectra Electrochemical properties TD-DFT calculations 



This work has been supported by a Grant-in-Aid for Scientific Research (Nos. 26410080, 15K17897, 15H00877, 16K05722) from the Ministry of Education, Culture, Sports and Technology (MEXT), Japan. The authors are grateful to Dr. Michiko Egawa (Shimane University) for her measurements of elemental analysis.

Supplementary material

11696_2017_244_MOESM1_ESM.cif (1.4 mb)
Supplementary material 1 (CIF 1401 kb)
11696_2017_244_MOESM2_ESM.pdf (4.2 mb)
Crystallographic data for the structure of complex 2(MeCN)2 reported in this paper have been deposited with the Cambridge Crystallographic Data Centre, CCDC no. 1537380. Copies of the information may be obtained free of charge from: The Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK (fax: +44-1223-336033; e-mail: or via (PDF 4316 kb)


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Copyright information

© Institute of Chemistry, Slovak Academy of Sciences 2017

Authors and Affiliations

  • Makoto Handa
    • 1
  • Satoshi Nishiura
    • 1
  • Takafumi Masuda
    • 1
  • Natsumi Yano
    • 1
  • Masahiro Mikuriya
    • 2
  • Yusuke Kataoka
    • 1
  1. 1.Department of Chemistry, Interdisciplinary Graduate School of Science and EngineeringShimane UniversityMatsueJapan
  2. 2.Department of Applied Chemistry for Environment and Research Center for Coordination Molecule-based Devices, School of Science and TechnologyKwansei Gakuin UniversitySandaJapan

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