Carboranylcarboxylate ligands as versatile building blocks for coordination polymers: efficient epoxidation catalysts

The presence of a metal–ligand association in metal coordination compounds can lead to the generation of suitable materials with a particular usefulness or applicability. In this sense, coordination polymers are currently of... [ view full abstract ]

The presence of a metal–ligand association in metal coordination compounds can lead to the generation of suitable materials with a particular usefulness or applicability. In this sense, coordination polymers are currently of great interest and represent an active area of coordination chemistry because of their special roles in fields such as catalysis, among others.

Closo boron clusters are tridimensional aromatic compounds [1] with highly stable structures very suitable for chemically harsh conditions.[2a] Therefore the ortho-C₂B₁₀H₁₂ offers more possible derivatizations in a small volume than the vast majority of the available chemical scaffoldings; further, it also offers very distinct environments in a very short distance, e.g. one lipophilic environment next to a hydrophilic one. Consequently, using carboranes in supramolecular chemistry is a field to be explored for their particular characteristics that shall induce unconventional properties in the structures in which they are inserted.[2b,c] Recently, we reported the coordination of carboranylcarboxylate ligands with Cu^II,[3] but the coordination chemistry of these ligands remained mostly unexplored. On the other hand, although a large number of half and mixed sandwich metalladicarbollide complexes have been reported as active catalysts in organic transformations, compounds containing closo-carboranylcarboxylate ligands have never been tested in metal-catalyzed oxidation reactions.

In this context, the study of the coordination of carboranylcarboxylate ligands to Mn^II and Co^II, the physical and chemical properties of the complexes and their reactivity towards the epoxidation of aromatic and aliphatic alkenes will be presented. 

[1] Poater, J.; Solà, M.; Viñas, C.; Teixidor, F. Angew. Chem. Int. Ed. 2015, 53(45), 12191–12195.

[2 ] a) Grimes, R. N. Carboranes, 3^rd Ed., Elsevier Inc. 2016; b) Nuñez, R; Romero, I.; Teixidor, F.; Viñas, C. Chem. Soc. Rev., 2016, 45, 5147-5173; 

 [3] a) Fontanet, M.; Popescu, A.R.; Fontrodona, X.; Rodriguez, M.; Romero, I.;Teixidor, F.; Viñas, C.; Ruiz E.; Aliaga-Alcalde, N. Chem. Eur. J., 2011, 17, 13217-13229; b) Fontanet, M.; Rodriguez, M.; Romero, I.; Fontrodona, X.; Teixidor, F.; Viñas, C.; Aliaga-Alcalde, N.; Matějíček, P. Chem. Eur. J. 2014, 20, 13993-14003; c) Fontanet, M.;Fontrodona, X.; Rodriguez, M.; Romero, I.;Teixidor, F.; Viñas, C.;  Aliaga-Alcalde, N. Dalton Trans., 2016, 45, 10916-10977; d) Fontanet, M.; Rodriguez, M.;  Viñas, C.; Teixidor, F.; Romero, I. Eur. J. Inorg. Chem. 2017, DOI: 10.1002/ejic.201700361