Aluminum metal–organic framework as a new host for preparation of encapsulated metal complex catalysts

Encapsulation of an organometallic cationic catalyst by direct exchange into an anionic MOF

“…The reverse route (“ship in a bottle” method) in which the TM catalyst is assembled in situ inside the pores of the host under milder conditions, was originally employed in zeolites 48 – 53 and has been recently also demonstrated in MOFs. 54 , 55 However, more than one step is again required (encapsulation of the desired TM species followed by ligand assembly and coordination) and the presence of catalytic species with different coordination motifs due to side reactions is potentially problematic. It should be also noted that both methods, although chemically elegant, require a very specific host–guest combination since the catalyst must be small enough to fit inside the pores but still large enough to avoid leaching through the pore windows.…”

Heterogenisation of polyoxometalates and other metal-based complexes in metal–organic frameworks: from synthesis to characterisation and applications in catalysis

“…A detailed study on the influence of the catalyst's loading on the relative intensity of the PXRD peaks of the composite was reported for CuPhen@MIL-100(Al), isolated by a ship in a bottle mehod. 156 The authors showed that the intensity of the Bragg peak at 2 = 4.0° gradually decreases when the amount of immobilized CuPhen increases (Fig. 15).…”

“…13 C CP-MAS NMR of CuPhen@MIL-100(Al) exhibits signals assigned to the aromatic carbons and carboxylate groups of the MOF's linkers and Phen ligand. 156 The single broad peak observed at ~15 ppm in the 31 P{ 1 H} MAS NMR spectrum of [Ir(cod)(PCy3)(py)]@NaSO3-MIL-101(Cr) is assigned to PCy3 ligands. 155 The absence of peak characteristic of PF6anions (around -146 ppm) suggests that the cation exchange is indeed complete.…”

“…A few years later, the oxidation of cyclohexane with similar types of catalysts was investigated by Chen et al. 156 In this case, tris(1,10-phenanthroline) Cu(II) complex (CuPhen) was encapsulated in two steps into MIL-100(Al). The oxidation of cycloalkane with the resulting CuPhen@MIL-100(Al) catalyst (0.55 wt % Cu content) was studied in acetonitrile using H2O2 as oxidant.…”

“…The dashed line indicates the position of the 2 = 4.0° Bragg peak. Adapted with permission from ref 156. .…”