al. (2015) Effect of the functionalisation route on a Zr-MOF with an Ir-NHC complex for catalysis.Chemical Communications, 51(54):

Bifunctional complexes bearing N-heterocyclic carbene (NHC) ligands functionalized with hydroxy or amine groups were synthesized to measure the beneficial effect of different modes of metal–ligand cooperation in the acceptorless dehydrogenation of alcohols. In comparison to complexes with an amine moiety, hydroxy-functionalized iridium catalysts showed superior activity. In contrast to alcohols, 1,4-diols underwent cyclization to give the corresponding tetrahydrofurans without involving dehydrogenation processes. Mechanistic investigations to rationalize the “OH effect” in these types of complexes have been undertaken.

A ruthenium complex formed from commercially available [Ru(p-cymene)Cl2]2 and 1,4-bis(diphenylphosphino)butane catalyzes the racemization of aromatic α-hydroxy ketones very efficiently at room temperature. The racemization is fully compatible with a kinetic resolution catalyzed by a lipase from Pseudomonas stutzeri. This is the first example of dynamic kinetic resolution of α-hydroxy ketones at ambient temperature in which the metal and enzyme catalysts work in concert in one pot at room temperature to give quantitative yields of esters of α-hydroxy ketones with very high enantioselectivity.

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We report the synthesis of the hitherto unknown zwitterionic alkoxyamino cyanoboranes by reduction of O-alkyloximes with sodium cyanoborohydride; unprecedented cyanoboronated N-alkoxyformamidines were also isolated as by-products. Boronated alkoxyamines were found to be efficient cyanoborane transfer agents towards more basic amines, including aminosugars; they were also successfully transformed into neoglycoconjugates by the neoglycorandomization reaction with reducing sugars.

Herein, we report three IrIIICp* complexes with hydroxy‐ or amino‐functionalized N‐heterocyclic carbene (NHC) ligands that catalyze efficient water oxidation induced by addition of ceric ammonium nitrate (CAN). The pendant hydroxy or amino groups are very important for activity, and the complexes with heteroatom‐functionalized NHC ligands show up to 15 times higher rates of oxygen evolution in CAN‐induced water oxidation than a reference IrIIICp* complex without heteroatom functionalization. The formation of molecular high‐valent Ir intermediates that are presumably involved in the rate‐determining step for water oxidation is established by UV/Vis spectroscopy and ESI‐MS under turnover conditions. The hydroxy groups on the NHC ligands, as well as chloride ligands on the iridium center are proposed to structurally stabilize the high‐valent species, and thereby improve the catalytic activity. The IrIII complex with a hydroxy‐functionalized NHC shows the highest catalytic activity with a TON of 2500 obtained in 3 h and with >90 % yield relative to the amount of oxidant used.

A method for the synthesis of hollow lanthanide doped yttrium oxyfluoride (YOF) spheres in the micrometer size range with cubic structure based on the pyrolysis at 600ºC of liquid aerosols generated from aqueous solutions containing the corresponding rare earth chlorides and trifluoroacetic acid has been developed. This procedure, which has been used for the first time for the synthesis of YFO based materials, is simpler and advantageous when compared with other methods usually employed for the production of hollow spheres since it does not require the use of sacrificial templates. In addition, it is continuous, which is desirable because of practical reasons. The procedure is also suitable for doping the YOF spheres with europium cations resulting in down converting red phosphors when activated with UV light, or for co-doping with both Er