## 3 Results and Discussion  
MOFs containing lead, copper, and iron were synthesized via microwave irradiation in surfactant reaction media. PEG 200 worked well for the lead containing MOF (MOF-1), while with the copper MOFs, PEG 200 led to the formation of visible amounts of CuO and, therefore, PEG 400, Surfonic(r) JL 80X, or nonanoic acid were used as alternatives. In keeping with the PEG theme, and since PEG 400 was a successful reaction media for the copper MOF synthesis, it was also carried through to the synthesis of the iron MOF (MOF-5). For the lead and copper MOFs, 100% surfactant was used as the reaction medium, while for the iron MOF (MOF-5), a 50/50 wt. % of PEG 400/water mixture was used as the reaction medium. Surfactants in combination with microwave irradiation provided more efficient synthetic conditions, in most cases reducing reaction times from days to hours and eliminating commonly used organic solvents such as DMF. MOFs 1-5 were each characterized using FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The IR spectrum of MOF-1 is compared to that of 5-_tert_-butylisophthalic acid in Figure S1, where the disappearance of: the -OH stretching band (3300-2500 cm\({}^{-1}\)), the normal dimeric carboxylic C=O stretch (1700 cm\({}^{-1}\)), and the dimeric C-O stretch (1290 cm\({}^{-1}\)) can be observed as well as the ingrowth of the asymmetric carboxylate stretch at 1538 cm\({}^{-1}\). These changes in spectra from neat carboxylic acid to reaction product indicate the 5-_tert_-butylisophthalate ligand is now bound to the lead ion in MOF-1. A lead 5-_tert_-butylisophthalic acid MOF was previously synthesized by [PERSON] et al. via conventional heating for 3 days in DMF with the formula, [Pb4(C12H12O4)4(DMF)4] [55]. While the reaction conditions of MOF-1 did not incorporate DMF, the IR spectrum, PXRD, and TGA (Figures 1, 2 and S1), all appear similar to those of [Pb4(C12H12O4)4(DMF)4] [55]. This indicates a [Pb4(C12H12O4)4(solvent)x] like MOF formed from microwave irradiation in PEG 200, either without any coordinating solvents or with water molecules (small amounts present in PEG 200) in place of the DMF molecules. As is expected with microwave irradiation, the crystals of MOF-1 are much smaller than those grown over multiple days by [PERSON] et al. using solvothermal methods (Figure 2) [55]. As shown in Figure 2, aggregates of indistinct small crystals formed in the microwave reaction make it difficult to achieve a single crystal for XRD analysis. TGA analysis of MOF-1 shows thermal stability up to 421 \({}^{\circ}\)C (Figure S2). Figure 1: Powder X-ray diffractogram of metal-organic framework (MOF)-1. Figure 2: SEM Images of MOF-1. Increasing magnification from 100\(\times\) (**a**) to 5000\(\times\) (**b**). MOFs 2-4 were synthesized via several different combinations of copper nitrate trihydrate, trimesic acid, and surfactant. The IR spectra of MOFs 2-4 are plotted with commercially available HKUST-1 (Basolite(r) C300), [Cu\({}_{3}\)(BTC)\({}_{2}\)], clearly showing the same vibrational frequencies (Figure S3). PXRD analysis also confirms the structural similarity in spite of the variation in reaction media (Figure 3). The SEM images (Figure 4) of MOFs 2-4 show a difference in morphologies as the surfactant is varied. All form aggregates of microcrystals. MOFs 2 and 3 appear to be the most crystalline, visually. MOF-2 crystal sizes are in the order of \(\sim\)0.25-1.0 \(\upmu\)m, while MOF-3 has slightly larger crystal sizes (\(\sim\)0.5-1.5 \(\upmu\)m). MOF-4 displays the smallest surface features, appearing to be the least crystalline. These crystal sizes are smaller than those reported by conventional heating in water and ethanol of \(\geq\)20 \(\upmu\)m, yet larger than those conventionally synthesized in PEG 400/P104 at 2-3 nm [45; 50]. However, the presence of distinct and sharp PXRD peaks, matching those of commercially available Basolite(r) C300, supports all being crystalline products.