Metallo-organic ensembles of tritopic subphthalocyanine ligands

Organic building blocks containing amines and aldehydes can be used for the preparation of complex metallo-organic structures, such as M[Formula: see text]L[Formula: see text] triple helicates or face-capped M[Formula: see text]L[Formula: see text] 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 (C[Formula: see text]-SubPc1 and C[Formula: see text]-SubPc1) have been prepared from the corresponding C[Formula: see text]-SubPcI[Formula: see text] and C[Formula: see text]-SubPcI[Formula: see text] precursors under optimized Suzuki conditions. We selected the tritopic C[Formula: see text]-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 Fe[Formula: see text]SubPc[Formula: see text] structures and/or Fe[Formula: see text]SubPc[Formula: see text] species, which can be considered as open precursors of Fe[Formula: see text]SubPc[Formula: see text] tetrahedral cages.