Synthesis and structural characterization of a diruthenium pentalene complex, \([\hbox {Cp}^{*}\hbox {Ru}\{(\hbox {Cp}^{*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {Cp}^{*}\hbox {Ru})]\)

  • Benson Joseph
  • Subrat Kumar Barik
  • Soumya Kumar Sinha
  • Thierry Roisnel
  • Sundargopal GhoshEmail author
Regular Article



Treatment of nido-[1,2-(Cp*Ru)\(_{2}\)(\(\mu \)-H)\(_{2}\)B\(_{3}\)H\(_{7}\)], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue \([(\hbox {Cp*}\hbox {Ru})\{(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {RuCp*})]\), 2 and a metal indenyl complex \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)], 3. The \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\)] fragment in 2 may be considered as a true metal–boron analogue of \(\upeta ^{5}\)-\(\upeta ^{5}\)-pentalene ligand (\(\hbox {C}_{8}\hbox {H}_{6})\) and \([(\hbox {Cp*}\hbox {Ru})\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)] fragment in 3 is an analogue of \(\upeta ^{5}\)-indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3. Further, the density functional theory (DFT) calculations were performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of \([(\hbox {Cp*}\hbox {Ru})\hbox {B}_{8}\hbox {H}_{14}(\hbox {RuCp*})])\) reveals a lower HOMO–LUMO gap indicating less thermodynamic stability.

Graphical Abstract

SYNOPSIS Treatment of nido-[1,2-(Cp\({*}\)Ru)\(_{2}(\upmu \)-H)\(_{2}\)B\(_{3}\)H\(_{7}\)] with Te powder led to the isolation of diruthenium pentalene analogue \([(\hbox {Cp*}\hbox {Ru})\{(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{6}\hbox {H}_{14}\}(\hbox {RuCp*})]\) and a metal indenyl complex \([(\hbox {Cp*}\hbox {Ru})_{2}\hbox {B}_{2}\hbox {H}_{6}\hbox {C}_{6}\hbox {H}_{3}(\hbox {CH}_{3})\)].


Ruthenium boron pentalene indenyl metallaborane 



The generous support of the Council of Scientific & Industrial Research, CSIR (Project No. 01(2837)/15/EMR-II), New Delhi, India, is gratefully acknowledged. B.J. and S.K.B. thank UGC and IIT Madras for research fellowships. We are very thankful to Dr. Bijan Mondal for scientific discussion. We thank Dr. Babu Varghese (SAIF, IIT Madras) for X-ray data analysis. IIT Madras is gratefully acknowledged for computational facilities.

Supplementary material

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© Indian Academy of Sciences 2018

Authors and Affiliations

  1. 1.Department of ChemistryIndian Institute of Technology MadrasChennaiIndia
  2. 2.Institut des Sciences Chimiques de RennesUMR 6226 CNRS-Ecole Nationale Supérieure de Chimie de Rennes-Université de Rennes 1Rennes CedexFrance

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