A set of terms, definitions, and recommendations is provided for use in the classification of coordination polymers, networks, and metal–organic frameworks (MOFs). A hierarchical terminology is recommended in which the most general term is coordination polymer. Coordination networks are a subset of coordination polymers and MOFs a further subset of coordination networks. One of the criteria an MOF needs to fulfill is that it contains potential voids, but no physical measurements of porosity or other properties are demanded per se. The use of topology and topology descriptors to enhance the description of crystal structures of MOFs and 3D-coordination polymers is furthermore strongly recommended.

Coordination polymers (CPs) and metal–organic frameworks (MOFs) are among the most prolific research areas of inorganic chemistry and crystal engineering in the last 15 years, and yet it still seems that consensus is lacking about what they really are, or are not.

The first bio-inspired microporous metal-organic framework (MOF) synthesized using ellagic acid, a common natural anti-oxidant and polyphenol building unit, is presented. Bi₂O(H₂O)₂(C₁₄H₂O₈)·nH₂O (SU-101) was inspired by bismuth phenolate metallodrugs, and was synthesized entirely from non-hazardous or edible reagents under ambient aqueous conditions, ena-bling simple scale-up. Reagent-grade and affordable dietary supplement-grade ellagic acid were sourced from tree bark and pomegranate hulls, respectively. Biocompatibility and colloidal stability were confirmed by in vitro assays. The material exhibits remarkable chemical stability for a bio-inspired MOF (pH = 2-14, hydrothermal conditions, heated organic solvents, biological media, SO₂ and H₂S), attributed to the strongly chelating phenolates. A total H₂S uptake of 15.95 mmol g-1 was recorded, representing one of the highest H₂S capacities for a MOF, where polysulfides are formed inside the pores of the material. Phenolic phytochemicals remain largely unexplored as linkers for MOF synthesis, opening new avenues to design stable, eco-friendly, scalable, and low-cost MOFs for diverse applications, including drug delivery.

Bismuth subgallate was revealed as a coordination polymer providing insight into its solubility and gas sorption properties.