DUGi

Building complexity in O2-binding copper complexes: site-selective metalation and intermolecular O2-binding at dicopper and heterometallic complexes derived from an unsymmetric ligand

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@295614

A novel unsymmetric dinucleating ligand (LN3N4) combining a tridentate and a tetradentate binding sites linked through a m-xylyl spacer was synthesized as ligand scaffold for preparing homo- and dimetallic complexes, where the two metal ions are bound in two different coordination environments. Site-selective binding of different metal ions is demonstrated. LN3N4 is able to discriminate between CuI and a complementary metal (M′ = CuI, ZnII, FeII, CuII, or GaIII) so that pure heterodimetallic complexes with a general formula [CuIM′(LN3N4)]n+ are synthesized. Reaction of the dicopper(I) complex [CuI 2(LN3N4)]2+ with O2 leads to the formation of two different copper-dioxygen (Cu2O2) intermolecular species (O and TP) between two copper atoms located in the same site from different complex molecules. Taking advantage of this feature, reaction of the heterodimetallic complexes [CuM′(LN3N4)]n+ with O2 at low temperature is used as a tool to determine the final position of the CuI center in the system because only one of the two Cu2O2 species is formed

Financial support for this work was provided by the European Commission (FP7-PEOPLE-2011-CIG-303522 to A.C. and ERC-2009-StG-239910 to M.C.), MINECO (CTQ2012-37420-C02-01/BQU and CSD2010-00065 to M.C.) and Generalitat de Catalunya (ICREA Academia Award to M.C.). The Spanish Ministry of Science is acknowledged for a Ramon y Cajal contract to A.C. We are thankul to Dr. X. Ribas for financial support from INNPLANTA Project No. INP-2011-0059-PCT-420000-ACT1. We also thank Dr. L. Gomez (Serveis Tecnics de Recerca, Universitat de Girona) for helpful advice in setting up the HR-MS experiments and for fruitful discussions. We thank Catexel for a generous gift of 1,4,7-tritosyl-1,4,7-triazacyclononane

American Chemical Society (ACS)