A new member of tetranuclear dinitrosyl iron complexes (DNICs) with 2-mercaptothiazoline ligand: synthesis, structure and properties

[[abstract]]A new tetranuclear dinitrosyliron complex [(μ-SC3H4SN)Fe(NO)2]4 (2), each of a Fe center coordinated with two S or two N, was prepared by CO replacement from the reduced precursor (CO)2Fe(NO)2 with 1 equiv of HSC3H4SN (2-mercaptothiazoline) in the presence of O2(g). The structure of 2 is similar to [(Imid-iPr)Fe(NO)2]4 (Imid-iPr = 2-isopropylimidazole) (Hess et al. J Am Chem Soc 133:20426–20434, 2011), and both complexes comprise a quadrilateral plane of irons with corresponding ligands, SC3H4SN− or Imid-iPr−, bridging the edges and two nitrosyl ligands capping the irons at the corners. An additional equiv of SC3H4SN− was added to 2, which results in the mononuclear {Fe(NO)2}9 (SC3H4SN)2Fe(NO) 2 − (3), in the manner of N bound-[SC3H4SN]. Reaction of (TMEDA)IFe(NO)2 (TMEDA = tetramethylethylenediamine) and complex 3 leads to the formation of complex 2. Dinuclear complex [(μ-C5H7N2)Fe(NO)2]2 (4) can be synthesized by the ligand displacement of SC3H4SN− to C5H7N2 − (3,5-dimethylpyrazolate) of 2 (Chong et al. Can J Chem 57:3119–3125, 1979). Complexes 2–4 were characterized by IR and UV–Vis. The molecular structures of 2 and 3 were determined by X-ray single crystal diffraction.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]NL

Experimental realization of long-distance entanglement between spins in antiferromagnetic quantum spin chains

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Flipping the Photoswitch: Ion Channels Under Light Control

Nature has incorporated small photochromic molecules, colloquially termed 'photoswitches', in photoreceptor proteins to sense optical cues in photo-taxis and vision. While Nature's ability to employ light-responsive functionalities has long been recognized, it was not until recently that scientists designed, synthesized and applied synthetic photochromes to manipulate many of which open rapidly and locally in their native cell types, biological processes with the temporal and spatial resolution of light. Ion channels in particular have come to the forefront of proteins that can be put under the designer control of synthetic photochromes. Photochromic ion channel controllers are comprised of three classes, photochromic soluble ligands (PCLs), photochromic tethered ligands (PTLs) and photochromic crosslinkers (PXs), and in each class ion channel functionality is controlled through reversible changes in photochrome structure. By acting as light-dependent ion channel agonists, antagonist or modulators, photochromic controllers effectively converted a wide range of ion channels, including voltage-gated ion channels, 'leak channels', tri-, tetra- and pentameric ligand-gated ion channels, and temperaturesensitive ion channels, into man-made photoreceptors. Control by photochromes can be reversible, unlike in the case of 'caged' compounds, and non-invasive with high spatial precision, unlike pharmacology and electrical manipulation. Here, we introduce design principles of emerging photochromic molecules that act on ion channels and discuss the impact that these molecules are beginning to have on ion channel biophysics and neuronal physiology