Copper trimesate

Figure 2.32 Examples of structures based on paddle wheel dimer units. In the copper trimesate HKUST-1, (top, left and right), dimeric copper units link four trimesate ligands into a three-dimensional framework, leaving the apical coordination site accessible to other ligands (such as water molecules). In the pillared layered zinc terephthalate of Dybtsev et al. porous planar zinc terephthalate sheets (shown) are linked via the diamine diazabicyclo-octane (N(C2H4)3N) coordinated at the apical sites.

If one assumes that terephthalate-based MOFs would be metabolized in the body simply to terephthalic acid, then perhaps examples with benign metals, for example, MIL-53(Fe), could be considered edible. This simplification does not consider any potential nanotox-ological health issues associated with the size of any persistent MOF particles. Similarly, trimesic acid (1,3,5-benzenetricarboxylic acid) is considered safe for human consumption, although toxicity data is based again on animal studies. Trimesic acid has been widely used as a MOF strut, with the copper trimesate HKUST-1 (Figure 3c) being examined for a number of appHcations. 

Figure 3 Solid-state structures of archetypal MOFs containing simple exogenous ligands, (a) MOF-5 (CCDC deposition SAHYIK), a cubic zinc terephthalate. (b) The flexible iron terephthalate, MIL-53(Fe) lt (CCDC deposition POJTUE), in its hydrated, as-synthesized form, (c) HKUST-1 (CCDC deposition FIQCEN), a copper trimesate. Non-coordinated solvents and protons removed for clarity...

Finally we address an STM study providing direct insight into the formation of coordination compounds at a Cu(100) surface, whereby translational and rotational molecular motions are involved. Towards this goal a molecular building block — 1,3,5-benzenetricarboxylic acid (trimesic acid, tma) — was deposited on the copper substrate. At room temperature the carboxylic acid moieties deprotonute and the resulting trimesate admolecules bind flat on... 

The tbo net is another prototypical platform for MOFs. The most famous example is HKUST-1 synthesized from trimesic acid (H3BTC) and copper salts. Yaghi and coworkers reported that using longer variants of BTC ligand such as 4,4, 4"-s-triazine-2,4,6-triyltribenzoate (TATB), 4,4, 4"-s-triazine-l,3,5-triyltrip-aminobenzenecarboxylic acid (H3TATAB), 4,4, 4"-(1,3,4,6,7,9,9b-heptaazaphenalene-2,5,8-triyl)tribenzoate... 

The described mechanochemical methodologies have obvious advantages over solvothermal approaches used for porous MOF synthesis in terms of time (minutes vs days), temperature (near room-temperature vs 100-150 °C), and reactant choice (metal oxides vs soluble salts). Further advantages are the absence of bulk solvent and a wide choice of catalytic liquid phases, including ethanol, which is one of the more preferred solvents from a Green Chemistry perspective. The only waste product of the oxide-based reaction is water. The functional nature of porous MOFs obtained mechanochemically was recently investigated by Yuan and coworkers, who found that the Brunauer-Emmett-Teller (BET) surface area of the exemplary MOF HKUST-1 obtained by neat grinding of copper(II) acetate monohydrate with trimesic acid was comparable to that of samples obtained by conventional... 

---