Bio-inspired synthetic approaches: from hierarchical, hybrid supramolecular assemblies to CaCO3-based microspheresElectronic supplementary information (ESI) available: Full experimental procedures and crystallographic data in CIF format for the new structure. CCDC 793553. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt00914c

A bio-inspired synthetic approach to unprecedented hybrid supramolecular assemblies [Ca(Me 2 hda)(H 2 O) 3 ]·H 2 O ( 1 ) and [Ca(C 12 hda)(H 2 O) 2 ]·H 2 O ( 2 ), that are stabilized by iminodiacetate-substituted organic ligands is reported. The results of the single-crystal X-ray analysis of 1 further allowed the use of electron microscopy to verify the supramolecular structure of the fibrous assemblies of 2 that incorporate extended alkyl-substituted ligand derivatives. 2 reveals interesting features that distinguish these soft structures from purely inorganic, brittle materials: meshes of nanobelts transform on solid supports to form homogeneous films covering extended, micro-sized areas. The use of the reported ligand system as a habit modifier for CaCO 3 results in hierarchical calcite aggregates. The structure-influencing effects of the ligands and their supramolecular assemblies promote the formation of calcite disks that tessellate into hollow microspheres that contain distinctive openings. A bio-inspired synthetic approach to Ca( ii )-based coordination assemblies is reported; the supramolecular system was used as habit modifier for CaCO 3 materials.