Journal of Chemical Sciences

, Volume 129, Issue 5, pp 561–571 | Cite as

Synthesis and structural studies of half-sandwich Cp* rhodium and Cp* iridium complexes featuring mono, bi and tetradentate nitrogen and oxygen donor ligands

  • Narasinga Rao Palepu
  • Werner Kaminsky
  • Mohan Rao Kollipara
Regular Article


A series of Cp*Rh and Cp*Ir complexes of various nitrogen and oxygen donor ligands were synthesized and characterized. Mono, bi and tetradentate ligands were used to synthesize mononuclear and dinuclear complexes. Schiff base derivatives of picolinic hydrazine and 5-aminoquinoline were used in the synthesis of complexes 18. Among the ligands used for complexation, L1 and L2 act as bidentate, L3 as monodentate and L4 as tetradentate in forming the corresponding complexes. All the complexes were characterized by spectroscopic techniques and the structures of complexes 2, 3, 5 and 7 were unambiguously characterized by single crystal X-ray crystallography. Complexes 2 and 7 were found to have \({\uppi }\)-\({\uppi }\) stacking interactions and solvent to complex interactions, respectively. Metal-mediated deprotonation of N-H and monodentate binding of nitrogen are attributed to the formation of neutral complexes whereas ionic complexes are formed by (N,O) bonding.

Graphical Abstract

SYNOPSIS Half-sandwich Cp* rhodium and Cp* iridium complexes of Schiff base derivatives of picolinic hydrazine and 5-aminoquinoline were synthesized, characterized and their structures studied by single crystal X-ray analysis. Various binding modes of the complexes were unambiguously confirmed.


Picolinic hydrazine fluorene 2-carbaldehyde rhodium iridium 



P N Rao thanks, UGC, New Delhi for providing a fellowship (SRF). We thank SAIF and DST-PURSE, SCXRD of NEHU for NMR and X-ray analysis data.

Supplementary material

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Copyright information

© Indian Academy of Sciences 2017

Authors and Affiliations

  1. 1.Centre for Advanced Studies in ChemistryNorth-Eastern Hill UniversityShillongIndia
  2. 2.Department of ChemistryUniversity of WashingtonSeattleUSA

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