engleski

Halogen Bonding Interaction in Assemblies of Metal Complexes: Resemblance to Hydrogen Bond

Halogen bond has relatively recently been recognized as an important structure-directing interaction and added to the crystal engineering tool box. In many organic materials (including a large range of pharmaceutically relevant compounds) it frequently acts as a key structure-directing force, even in competition with more commonly appreciated interactions such as HB or π−π stacking. On the other hand, even though large number of well-known ligands that are extensively used in coordination chemistry are decorated with one or more halogen atoms capable of acting as halogen-bond donors, metal-organic systems that rely on XBs have not received anywhere near the same attention. Inherent complexity in controlling metal containing systems, due to the presence of multiple potential acceptor sites is one of the reasons for the pronounced imbalances, regardless if assemblies rely on halogen bond or its hydrogen bonding analogue. In this contribution we present the similarity of halogen-bonding interaction with its hydrogen-bonding analogue in assembling metal complexes of several 0-1 and 1-D model systems. For this purpose we utilize small N- heterocyclic ligands encoded with functional groups capable of directional hydrogen and halogen bonding as a way of connecting adjacent Cu(II) and Cd(II) complexes in a desirable manner. Structural data have been complemented by CSD data mining and extensive computational methods to facilitate the interpretation of the experimental efforts. In addition, several structure- property correlations are presented.

halogen bond ; cadmium ; copper ; N-heterocyclic ligands

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