The scorpionate ligands have been known for many years and represent a major class of ligand system.
In 1966, Trofimenko coined the term ‘‘scorpionates’’ to represent tripodal ligand systems which bind
tightly to transition metal centres.[1] Originally, the term was used to depict polypyrazolylborate
ligands, however this generally accepted analogy is now used to describe plenty of multidentate ligand
systems which bind to transition metals centres like the claws of a scorpion.[2] These ligands have
opened up significant potential particularly in such transformations where the ligand becomes closely
involved within the activation process, so called ‘‘ligand cooperation’’.[3] The interest in scorpionate
ligands is not restricted only to the synthesis of its metal complexes but also due to the fact that these
metal complexes are fulfilling the goals in the area of bond activation. In 1999, Hill reported the
formation of the first authenticated transition metal–borane complex utilising Reglinski’s
hydrotris(methimazolyl)borate as ligand precursor that undergoes B-H activation (stinging) at the
metal center to provide the unprecedented metallaboratrane structural motif.[4] In this seminar, recent
developments of scorpionate ligands and the utilisation of scorpionate ligand metal complexes in the
activation of small molecules as well as preliminary results of my research work will be discussed.
References:
[1]. S. Trofimenko, J. Am. Chem. Soc., 1966, 88, 1842.
[2]. (a) S. Trofimenko, Scorpionates: The Coordination of Poly(pyrazolyl)borate Ligands, Imperial College Press, London,
1999 (b) S. Trofimenko, Polyhedron, 2004, 23, 197. (b) S. Trofimenko, Polyhedron,2004, 23, 197.
[3]. (a) C. Gunanathan and D. Milstein, Acc. Chem. Res., 2011, 44, 588. (b) J. R. Khusnutdinova and D. Milstein, Angew.
Chem.,Int. Ed., 2015, 54, 12236.
[4]. (a) A. F. Hill, G. R. Owen, A. J. P. White and D. J. Williams, Angew. Chem., Int. Ed., 1999, 38, 2759. (b) N. Tsoureas , Y.-Y.
Kuo , M. F. Haddow and G. R. Owen , Chem. Commun., 2011, 47 , 484.