Nitrosyl Rhenium Complexes: Iodonitrosyl derivatives

The anionic Re(NO)I₅^2? has been isolated as salts of Cs⁺, Rb⁺, and dipyH⁺. The nonelectrolytic Re(NO)I₃L (L stands for 1,10-phenanthroline and 2,2′-dipyridyl) and cationic [Re(NO)IL₂]PtCl₆ have also been prepared. From a solution of Re(NO)(OH)₃ in HI, compound of formula Re(H₂O)(NO)(OH)I₂ has been isolated, pyrolysis of which yielded Re(H₂O)_0.5(NO)(OH)₂I. Measurements of electronic and i.r. spectra and magnetic moments have been carried out. The properties of the iodo derivatives have been compared with those of the corresponding fluoro, chloro and bromo complexes.     

Nitrosyl derivatives of group VI metals containing monodentate amines

Summary Passage of a slow stream of nitric oxide through a benzene solution of M(CO)₅(Am), (M = Mo and W; Am = BuNH₂, C₆H₁₁NH₂, PhCH₂NH₂, C₅H₁₁N, C₅H₅N and BuNO) yielded dimeric [M(NO)₃(Am)]₂ complexes which have been characterized by elemental analysis, magnetic data and i.r. spectra. The i.r. data indicate the presence of terminal as well as of bridging nitric oxide in the complexes.     

Nitrosyl rhenium complexes: Syntheses,properties, and structures of acetylacetonato derivatives

Some new complexes of rhenium containing monocoordinating acetylacetone viz. [Re(NO)(acac)₂(Cl)H₂O], Re(NO)(acac)₃(acacH)(H₂O)₂ have been synthesized by reacting acetylacetone with either Re(NO)Cl₃ · H₂O or Re(NO)(OH)₃ · H₂O. The preparation of [Re(NO)(py)(acac)₂(Cl) · H₂O], [Re(NO)(acac)(OH)(Cl) · H₂O], [Re₂(NO)₂(acacH)₃(acac)₂ · Cl₄], [Re(NO)(acac)₂(OH) · H₂O] · 2 H₂O have also been described. These complexes were characterized through their elemental analyses, u.v., vis, i.r., ¹Hn.m.r., magnetic, and conductance data.     

Room-Temperature Photogeneration of Nitrosyl Linkage Isomers in Ruthenium Nitrosyl Complexes

The conditions for the photogeneration of NO linkage isomers at room temperature are studied. By pulsed laser irradiation in the blue spectral range, the long-lived Ru−ON isomer can be generated at room temperature, which is crucial for potential applications, such as holography and data storage. By using static and time-resolved spectroscopy (UV/Vis and IR), we give evidence that the liftime of the Ru−(η²-(NO)) isomer is a decisive parameter for the formation of the Ru−ON isomer at high temperature owing to a two-step isomerization mechanism Ru−NO→Ru−(η²-(NO))→Ru−ON. Furthermore, we report the low-temperature structures for each isomer, which were revealed by photocrystallography.     

The Structures of Nitrosyl Fluoride and Nitrosyl Chloride in the Solid State

Nitrosyl fluoride and nitrosyl chloride are crystallized from the melt. The crystal structures are made up by ON–F and ON–Cl molecules with only weak intermolecular interactions. ON–F: a = 411.0(2), b = 439.1(2), c = 1020.2(4) pm, space group P2₁2₁2₁. ON–Cl: a = 1084.0(2), b = 543.5(1), c = 409.3(1) pm, space group Pnma. Both molecules have considerable longer nitrogen‐halogen bonds and shorter nitrogen‐oxygen bonds in the solid than in the gaseous state. These differences between gas and solid state structure are expressed much stronger in ON–Cl than in ON–F. ON–F functions as a solvate molecule in the cation of NO⁺(NOF)₂IF₈^–. Here the ON–F molecule has a drastically shortened NO and lengthened NF bond. NO⁺(NOF)₂IF₈^–: a = 618.9(1), b = 1039.4(1), c = 2842.1(1) pm, space group P2₁2₁2₁.     

Alkynyl and poly-ynyl derivatives of carbon-tricobalt clusters

A series of alkynyl-tricobalt carbonyl clusters, Co₃(μ₃-C_nR)(μ-dppm)(CO)₇ [R = Bu^t, Ph, C₆H₄I, C₆H₄CCPh, SiMe₃, Fc, Au(PPh₃)] containing three, five or seven carbons in the chain, have been prepared by elimination of phosphine-gold(I) halides in reactions between Co₃(μ₃-CBr)(μ-dppm)(CO)₇ and Au(CCR)(PPh₃) or between Co₃{μ₃-CCCAu(PR₃)} (μ-dppm)(CO)₇ (R = Ph, tol) and ICCR′ (R′ = SiMe₃, Fc). The use of poly-substituted arenes or ferrocenes has enabled preparation of the complexes 1,4-{(OC)₇(μ-dppm)Co₃ (μ₃-CCC)}₂C₆H₃X-5 (X = H, Br), 1,3,5-{(OC)₇(μ-dppm)Co₃(μ₃-CCC)}₃C₆H₃ and 1,1′-{(OC)₇(μ-dppm)Co₃ (μ₃-CCC)}₂Fc′ [Fc′ = Fe(η-C₅H₄-)₂]. The X-ray determined molecular structures of 12 of the complexes are reported.     

Pyridino Nitrosyl Complexes of Rhenium

Preparation of pyridine derivatives of ReCl₃(NO) viz. (pyH)₂ReCl₅(NO), pyH[ReCl₄py(NO)], H[ReCl₄py(NO)], K[ReCl₄py(NO)], Ag[ReCl₄py(NO)] and [ReCl₃py₂(NO)] are described. All these compounds are stable solids. They are characterised by their analytical composition, spectral data, conductance and magnetic moment values.     

新型NO供体的合成及其体外释放NO性能

新型NO供体的合成及其体外释放NO性能;金属卟啉;NO载体;合成;体外释NO作用     

Iron chalcogenide carbonyl clusters and their heterometallic derivatives

This paper reviews the results of XRD, Mössbauer, and¹H,⁷⁷Se, and¹²⁵Te NMR studies of the structure of iron chalcogenide carbonyl clusters with a Fe₃X (X = Se, Te) framework and a series of their heterometallic derivatives synthesized by successive replacement of mononuclear iron carbonyl fragments by isolobal metallorganic groups containing Mo and W.     

Nitrosyl Rhenium Complexes: Thiocyanato Derivatives

Fusion of K₂[Re(NO)Cl₅] with KSCN produces the ion [Re(NO)(SCN)₅]^2? which has been isolated as free acid and K⁺, Na⁺, NMe₄⁺, Pb²⁺, Hg²⁺, phen H⁺ and dipyH⁺ salts. A salt of composition Hg₂[Re(NO)(SCN)₇] has also been prepared. The species [Re(NO)Cl(SCN)₄]^2? has been obtained from the reaction of H₂[Re(NO)(SCN)₅] with HCl in aqueous medium and its NMe₄⁺ salt has been isolated. Hydrated Re(NO)Cl₃ reacts with KSCN in aqueous medium to produce the ion [Re(NO)Cl₂(SCN)₃]^2? which has been isolated as its phenH⁺ and dipyH⁺ salts. The complexes have been characterized through elemental analyses, spectral (u.v., vis., i.r.) properties, magnetic and conductance data. The structures of all those compounds have been proposed.     

Hexanuclear chloride and brimode tungsten clusters and their derivatives

Several hexanuclear chloride and bromide bridged tungsten clusters have been prepared. Two new oxo-bridged clusters, Na[W₆OBr₁₈] and [α-W₆(μ₂-OH)₄(μ₂-O)₆(μ₂-Cl)₂Cl₆]^2? are reported. Crystal structures of eight new tungsten cluster complexes with different core types were determined. The possibility of Se for Cl substitution in the {W₆Cl₈}⁴⁺ core was investigated.     

Photoluminescence quenching of quantum-confined cadmium sulfide clusters by norbornadiene derivatives

Influence of norbornadiene and its derivatives on the photoluminescence (PL) of quantum-confined cadmium sulfide clusters (Q-CdS) prepared in reverse micelles was investigated.It was found that norbornadiene-2,3-dicarboxylic acid (3) and its monopotassium salt (4) quenched PL intensity by 77% and 62%,respectively,whereas its dipotassium salt (5),norbornadiene (1) and norbornadiene-2,3-dimethylcarboxylate (2) had no effect on PL intensity.The formation constants for adducts formed between defect sites at the surface of Q-CdS clusters and 3 or 4 were also determined.PL quenching effect was attributed to the presence of ionizable proton which is considered to be able to trap photogenerated electrons and remove them from possible decay process.Measurements of the PL decay by single photon counting technique also supported these steady-state observations.     

Nitrosyl iron complexes--synthesis, structure and biology

Nitrosyl complexes of iron are formed in living species in the presence of nitric oxide. They are considered a form in which NO can be stored and stabilized within a living cell. Upon entering a topic in bioinorganic chemistry the researcher faces a wide spectrum of issues concerning synthetic methods, the structure and chemical properties of the complex on the one hand, and its biological implications on the other. The aim of this review is to present the newest knowledge on nitrosyl iron complexes, summarizing the issues that are important for understanding the nature of nitrosyl iron complexes, their possible interactions, behavior in vitro and in vivo, handling of the preparations etc. in response to the growing interest in these compounds. Herein we focus mostly on the dinitrosyl iron complexes (DNICs) due to their prevailing occurrence in NO-treated biological samples. This article reviews recent knowledge on the structure, chemical properties and biological action of DNICs and some mononitrosyls of heme proteins. Synthetic methods are also briefly reviewed.