CRYSTAL ENGINEERING OF O-CARBORANYL ALCOHOLS AND THEIR COBALT(II) COMPLEXES: SYNTHESES, STRUCTURAL STUDIES AND PROPERTIES

FLORENCIA DI SALVO; VINCENT TERRASSON; BEATRIZ CAMARGO; YOLANDA GARCÍA; JOSÉ GINER PLANAS; CLARA VIÑAS; FRANCESC TEIXIDOR; DAMIEN PRIM; MARK E. LIGHT; MICHAEL B. HURSTHOUSE

BOLOGNA

Conferencia; The Growing World of Crystal Forms. 5th Bologna convention on crystal form; 2010

Group of Molecular Crystal Engineering, U. of Bologna and PolyCrystalLine s.r.l

Crystal engineering, the ability to design and prepare molecular crystal structures by using the self-assembling properties of the molecules, is emerging as a powerful strategy for the construction of novel functional, nanoscale materials.[1] We have recently related the field of molecular crystal engineering with that of icosahedral heteroborane clusters.[2] In this report we will show our recent results on crystal engineering of o-carboranyl methylalcohols bearing nitrogenated aromatic rings. The presence of proton donor (OH) and acceptor (N) groups, hydrophobic icosahedral heteroborane clusters, and aromatic rings in these molecules offers enough supramolecular diversity to explore properly the interactions between molecules in crystal packing and their properties (Figure, I and II). We will show the formation of moderate hydrogen bonding, giving place to dimers, tetramers or infinite one-dimensional chains. Moreover, the mentioned functionalities (OH and N), open a new door to obtain very attractive carborane based transition metal complexes which could exhibit also interesting magnetic, thermal and structural behavior (Figure, III). Thus we will also present our first results on o-carboranyl methylalcohols based Co(II) complexes and show how the variation of the position of the N atom in the aromatic rings and the inclusion of substituents, either in the carborane cluster or the nitrogenated rings, offers the possibility to modulate their molecular interactions which finally leads to different structural characteristics and properties. [1] G. R. Desiraju, T. Steiner, The Weak Hydrogen Bond in Structural Chemistry and Biology, Oxford University Press, Oxford, 2001; D. Braga, F. Grepioni,  Making Crystals by Design, Wiley-VCH, 2007.  [2] J. G. Planas, F. Teixidor, C. Viñas, M. E. Light, M. B. Hursthouse, Chem. Eur. J. 2007, 13, 2493.