Ever since the founding work of Alfred Stock on borane chemistry, synthesis and characterization of
polyhedral boranes, have gained significant interest because of their multi-centre bonding features and
three dimensional aromaticity.[1] Isolation of the first closo-hydroborate dianions [B10H10]2- by Hawthorne
stimulated the search for other dianions and as a result, during the last 60 years, Lipscomb, Muetterties,
and Boone had succeeded isolating rest of the closo-hydroborate dianions [BnHn]2- (n = 6-12).[2] Whereas,
due to the intrinsic stability portrayed by B12 icosahedron, synthesis of supraicosahedral closo-boranes
[BnHn]2-, where n ≥ 13 is still a boron chemists dream. On the other hand, late transition metals promoted
the isolating of supraicosahedral metallaboranes, where metal is the part of the cluster. In contrast, group
4 metals helped isolating closo-pentagonal bipyramidal B7 core (III and IV) and triangular B3 core (I and II),
where exo-{MCp2} (M= Zr or Hf) fragments stabilize the clusters but they do not fit in the vertex of core
geometry.[3] As a result, we want to see if supraicosahedral closo-hydroborate dianions can be isolated
employing similar type synthetic methodology, where exo-{MCp2} fragments will act as stabilizing agent.
In this seminar, the potentiality of our synthetic strategy to synthesize closo-hydroborate dianion, as well
as preliminary result of my research work in this field will be discussed.
References:
[1]. (a) A. Stock, in Hydrides of Boron and Silicon, Cornell University Press, Ithaca, NY, 1933. (b) J. D. Kennedy, Prog. Inorg.
Chem., 1986, 36, 211; (c) P. v. R. Schleyer, G. Subramanian, H. Jiao, K. Najafian, M. Hofmann, in Advances in Boron
Chemistry, ed. W. Siebert, The Royal Society of Chemistry, Cambridge, U.K., 1997.
[2]. (a) W. L. Lipscomb, in Boron Hydrides, Benjamin, New York, 1963; (b) J. L. Boone, J. Am. Chem. Soc., 1964, 86, 5036;
(c) Boron Hydride Chemistry, ed. E. L. Muetterties, Academic Press, New York, 1975; (d) W. N. Lipscomb, A. R. Pitochelli,
M. F. Hawthorne, J. Am. Chem. Soc., 1959, 81, 58335834.
[3]. (a) D. K. Roy, B. Mondal, A. De, S. Panda, S. Ghosh, Organometallics, 2015, 34, 908912; (b) A. De, Q.-F. Zhang, B.
Mondal, L. F. Cheung, S. Kar, K. Saha, B. Varghese, L.-S. Wang, S. Ghosh, Chem. Sci., 2018, 9, 19761981.