Metallo-organic ensembles of tritopic subphthalocyanine ligands

Abstract

Organic building blocks containing amines and aldehydes can be used for the preparation of complex metallo-organic structures, such as M2L3 triple helicates or face-capped M4L4 tetrahedral cages, through the formation of both dynamic covalent and coordinative linkages during the self-Assembly process. Herein we describe how the subcomponent self-Assembly method can be succesfully applied over a triamine-functionalized subphthalocyanine (SubPc) ligand to build metallo-supramolecular helicates. Two isomeric SubPcs (C1-SubPc1 and C3-SubPc1) have been prepared from the corresponding C1-SubPcI3 and C3-SubPcI3 precursors under optimized Suzuki conditions. We selected the tritopic C3-SubPc1 derivative as ligand for the subcomponent self-Assembly experiments, which involved the reaction with 2-formylpyridine and different Fe(II) salts. The self-Assembly process was mainly studied by mass spectrometry (ESI direct injection techniques), and in all the conditions applied, we could observe the formation of helicate-Type Fe2SubPc3 structures and/or Fe2SubPc4 species, which can be considered as open precursors of Fe4SubPc4 tetrahedral cages. © 2017 World Scientific Publishing Company.