220339-96-8Relevant academic research and scientific papers
A metal ion regulated artificial metalloenzyme
Bersellini, Manuela,Roelfes, Gerard
, p. 4325 - 4330 (2017)
Regulation of enzyme activity is essential in living cells. The rapidly increasing number of designer enzymes with new-to-nature activities makes it necessary to develop novel strategies for controlling their catalytic activity. Here we present the development of a metal ion regulated artificial metalloenzyme created by combining two anchoring strategies, covalent and supramolecular, for introducing a regulatory and a catalytic site, respectively. This artificial metalloenzyme is activated in the presence of Fe2+ ions, but only marginally in the presence of Zn2+.
Coordination chemistry for antibacterial materials: A monolayer of a Cu2+ 2,2′-bipyridine complex grafted on a glass surface
Pallavicini, Piersandro,Dacarro, Giacomo,Grisoli, Pietro,Mangano, Carlo,Patrini, Maddalena,Rigoni, Federica,Sangaletti, Luigi,Taglietti, Angelo
, p. 4552 - 4560 (2013)
A propyltrimethoxysilane-modified 2,2′-bipyridine ligand is synthesized and its acetonitrile solutions are used to prepare monolayers of the molecule on glass surfaces. Absorption and X-ray photoelectron spectroscopy demonstrate that the modified glass surfaces bind Cu2+ with a 1:1 ratio with respect to the 2,2′-bipyridine moieties under the chosen preparative conditions, producing materials bearing 0.016 μg cm-2 of copper. Although in trace amounts, the bound Cu2+ cations exert a significant microbicidal effect against Escherichia coli and Staphylococcus aureus. The Royal Society of Chemistry 2013.
Rotaxane synthesis exploiting the M(i)/M(III) redox couple
Emerson-King, Jack,Knighton, Richard C.,Gyton, Matthew R.,Chaplin, Adrian B.
, p. 11645 - 11655 (2017/09/18)
In the context of advancing the use of metal-based building blocks for the construction of mechanically interlocked molecules, we herein describe the preparation of late transition metal containing [2]rotaxanes (1). Capture and subsequent retention of the interlocked assemblies are achieved by the formation of robust and bulky complexes of rhodium(iii) and iridium(iii) through hydrogenation of readily accessible rhodium(i) and iridium(i) complexes [M(COD)(PPh3)2][BArF4] (M = Rh, 2a; Ir, 2b) and reaction with a bipyridyl terminated [2]pseudorotaxane (3·db24c8). This work was underpinned by detailed mechanistic studies examining the hydrogenation of 1p;:p;1 mixtures of 2 and bipy in CH2Cl2, which proceeds with disparate rates to afford [M(bipy)H2(PPh3)2][BArF4] (M = Rh, 4a[BArF4], t = 18 h @ 50 °C; Ir, 4b[BArF4], t 2Cl2 (1 atm H2). These rates are reconciled by (a) the inherently slower reaction of 2a with H2 compared to that of the third row congener 2b, and (b) the competing and irreversible reaction of 2a with bipy, leading to a very slow hydrogenation pathway, involving rate-limiting substitution of COD by PPh3. On the basis of this information, operationally convenient and mild conditions (CH2Cl2, RT, 1 atm H2, t ≤ 2 h) were developed for the preparation of 1, involving in the case of rhodium-based 1a pre-hydrogenation of 2a to form [Rh(PPh3)2]2[BArF4]2 (8) before reaction with 3·db24c8. In addition to comprehensive spectroscopic characterisation of 1, the structure of iridium-based 1b was elucidated in the solid-state using X-ray diffraction.
New insights into dihydrogenphosphate recognition with dirhenium(i) tricarbonyl complexes bridged by a thiourea moiety
Blackburn, Anna L.,Baker, Naomi C. A.,Fletcher, Nicholas C.
, p. 18442 - 18452 (2014/05/20)
Three thiourea bridged 2,2′-bipyridine ligands bearing either a single thiourea group (L1), or two units separated by either a para (L2) or meta-substituted (L3) aromatic spacer, along with the corresponding bis(fac-tricarbonylrhenium(i)) complexes are reported. The three ligands all show the anticipated binding to acetate. However 1H NMR titrations reveal an unusual cooperative binding to, and selectivity for, two dihydrogenphosphate ions. The rhenium(i) complexes similarly demonstrate unusual sigmoidal titration curves, and in the case of {Re(CO)3Br} 2(μ-L1) a surprisingly strong interaction to two anions. These were further exemplified in the emissive behaviour leading to the conclusion that there is an unusual interaction with dihydrogenphosphate, giving an initial increase in the emission, followed by a decrease and a blue shift in wavelength possibly as a result of partial deprotonation. It appears that dihydrogenphosphate binds cooperatively, with the addition of a second anion enhancing the interaction of the first, probably by proton transfer; this could explain the remarkable selectivity for phosphate seen with many reported anion receptors.
Reductive couplings of 2-halopyridines without external ligand: Phosphine-free nickel-catalyzed synthesis of symmetrical and unsymmetrical 2,2'-bipyridines
Liao, Lian-Yan,Kong, Xing-Rui,Duan, Xin-Fang
, p. 777 - 782 (2014/04/03)
An unexpectedly facile synthetic approach for symmetrical and unsymmetrical 2,2'-bipyridines through the Ni-catalyzed reductive couplings of 2-halopyridines was developed. The couplings were efficiently catalyzed by 5 mol % of NiCl2.6H2O without the use of external ligands. A variety of 2,2'-bipyridines including caerulomycin F have been efficiently synthesized.
Enantioselective artificial metalloenzymes by creation of a novel active site at the protein dimer interface
Bos, Jeffrey,Fusetti, Fabrizia,Driessen, Arnold J. M.,Roelfes, Gerard
, p. 7472 - 7475 (2012/09/08)
A game of two halves: Artificial metalloenzymes are generated by forming a novel active site on the dimer interface of the transcription factor LmrR. Two copper centers are incorporated by binding to ligands in each half of the dimer. With this system up to 97% ee was obtained in the benchmark CuII catalyzed Diels-Alder reaction (see scheme). Copyright
