Dinuclear copper(I) complexes with N-heterocyclic thione and selone ligands: synthesis, characterization, and electrochemical studies.

The synthesis, characterization, and structures of a series of homoleptic and heteroleptic copper(I) complexes supported by N-heterocyclic chalcogenone ligands is reported herein. The quasi-reversible Cu(II/I) reduction potentials of these copper complexes with monodentate (dmit or dmise) and/or bidentate (Bmm(Me), Bsem(Me), Bme(Me), Bsee(Me)) chalcogenone ligands are highly dependent upon the nature and number of the donor groups and can be tuned over a 470 mV range (-369 to 102 mV). Copper-selone complexes have more negative Cu(II/I) reduction potentials relative to their thione analogs by an average of 137 mV, and increasing the number of methylene units linking the heterocyclic rings in the bidentate ligands results in more negative reduction potentials for their copper complexes.

Synthesis, characterization, photophysical properties, and catalytic activity of an SCS bis(N-heterocyclic thione) (SCS-NHT) Pd pincer complex.

Treatment of 1,3-bis(3'-butylimidazolyl-1'-yl)benzene diiodide with elemental sulfur in the presence of a base produced a bis(N-heterocyclic thione) (NHT) pincer ligand precursor. Its reaction with PdCl2(CH3CN)2 produced chloro[1,3-bis(3'-butylimidazole-2'-thione-κ-S)benzene-κ-C]palladium(ii), a 6,6-fused ring SCS-NHT palladium pincer complex. This air stable compound is, to our knowledge, the first SCS pincer complex that utilizes N-heterocyclic thione (NHT) donor groups.

Effect of head-group chemistry on surface-mediated molecular self-assembly.

Surface molecular self-assembly is a fast advancing field with broad applications in sensing, patterning, device assembly, and biochemical applications. A vast number of practical systems utilize alkane thiols supported on gold surfaces. Whereas a strong Au-S bond facilitates robust self-assembly, the interaction is so strong that the surface is reconstructed, leaving etch pits that render the monolayers susceptible to degradation.

Generation and optical properties of monodisperse wurtzite-type ZnS microspheres.

Monodisperse wurtzite-type ZnS microspheres have been prepared by using glutathione (GSH) as a sulfur source at low reaction temperatures ranging from 160 to 210 degrees C. The diameter of the ZnS microspheres can be tuned from approximately 254 to approximately 597 nm by changing the reaction parameters such as temperature, molar ratio of reactants (GSH/Zn2+), and reaction medium (ethylenediamine or ammonia). Our results demonstrate that monodentate amines (ammonia) play the same role as that of bidentate amines (ethylenediamine) in the formation of the wurtzite-type ZnS microspheres.

Growth and optical properties of wurtzite-type CdS nanocrystals.

This paper reports wurtzite-type CdS nanostructures synthesized via a hydrothermal reaction route using dithiol glycol as the sulfur source. The reaction time was found to play an important role in the shape of the CdS nanocrystals: from dots to wires via an oriented attachment mechanism. This work has enabled us to generate nanostructures with controllable geometric shapes and structures and thus optical properties.

Tris(mercaptoimidazolyl)borate complexes of the coinage metals: syntheses and molecular structures of the first gold compounds and related copper and silver derivatives.

The first tris(mercaptoimidazolyl)borate complexes of gold, Au(Tm(tBu)) and (Tm(tBu))Au(PPh3), have been prepared and structurally characterized. Together with their copper and silver analogues M(Tm(tBu)) and (Tm(tBu))M(PPh3)(M = Cu, Ag), these compounds constitute the first two complete series of Tm(R) derivatives to be isolated for the coinage metals. In order to evaluate the steric and electronic effects of the bulky tert-butyl substituents in these species, comparative structural analyses with the known methyl-substituted analogue Ag(Tm(Me)) and various (Tm(Me))M(PR3) derivatives (M = Cu, Ag) are also presented.

Mediator-template assembly of nanoparticles.

The ability to construct size- and shape-controllable architectures using nanoparticles as building blocks is essential for the exploration of nanoparticle-structured properties. This paper reports findings of an investigation of a mediator-template strategy for the size-controllable assembly of nanoparticles. This strategy explores multidentate thioether ligands as molecular mediators and tetraalkylammonium-capped gold nanoparticles (5 nm) as templates toward the preparation of size-controllable and monodispersed spherical assemblies ( approximately 20-300-nm diameters).

Manganese(I) poly(mercaptoimidazolyl)borate complexes: spectroscopic and structural characterization of Mn...H-B interactions in solution and in the solid state.

The manganese(I) tricarbonyl complexes (Bm(R))Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhBmMe)Mn(CO)3, the first bis(mercaptoimidazolyl)borate derivatives for this metal, have been readily prepared and fully characterized. In particular, the presence of three-center-two-electron Mn..

Cobalt tris(mercaptoimidazolyl)borate complexes: synthetic studies and the structure of the first cobaltaboratrane.

The paramagnetic complexes (TmtBu)CoX (X = Cl, Br, I) have been readily prepared and structurally characterized and provide a convenient entry into cobalt(II) tris(mercaptoimidazolyl)borate chemistry. A number of derivatives, including mononuclear triphenylphosphine adducts [(TmtBu)Co(PPh3)]X and dinuclear compounds [Co2(TmtBu)2X]Y, have been prepared in order to ascertain whether cobalt is a reliable surrogate for zinc in biological systems, particularly in sulfur-rich coordination environments. The structure of the first cobaltaboratrane is also reported.

Size-controlled assembly of gold nanoparticles induced by a tridentate thioether ligand.

The ability to control the size and shape of nanoparticle assemblies is essential for the ultimate applications in sensors, catalysis, medical diagnostics, information storage, and quantum computation. This report demonstrates a novel mediator-template strategy toward this ability by exploring molecular driving forces exerted by a tridentate thioether as a mediator and tetraoctylammonium bromide as a templating agent. A combination of the ligand mediation, the surfactant templating, and their relative concentrations served as the driving forces.

Homoleptic group 12 metal bis(mercaptoimidazolyl)borate complexes M(Bm(R))2 (M = Zn, Cd, Hg).

The sodium salt of the bis(2-mercapto-1-methylimidazolyl)borate anion [Bm(Me)](-) and those of the new bis(2-mercapto-1-alkylimidazolyl)borates [Bm(R)](-) (R = Bz, Bu(t), p-Tol) have been readily obtained from NaBH(4) and the appropriate 2-mercapto-1-alkylimidazoles. To contrast the binding preferences of the group 12 metals in a sulfur-rich environment, the four complete series of homoleptic complexes M[Bm(R)](2) (M = Zn, Cd, Hg), including the first bis(mercaptoimidazolyl)borate derivatives of cadmium and mercury, have been prepared. X-ray diffraction studies of Cd[Bm(Me)](2) and M[Bm(tBu)](2) (M = Zn, Cd, Hg) show the presence of distorted tetrahedral [MS(4)] central cores supplemented by two weak vicinal M.

Novel spherical assembly of gold nanoparticles mediated by a tetradentate thioether.

The ability to construct three- and two-dimensional architectures via nanoscale engineering is important for emerging applications of nanotechnology in sensors, catalysis, controlled drug delivery, microelectronics, and medical diagnostics. In this paper, we report novel 3D assembly using multidentate molecular building blocks. It is demonstrated that the interparticle linking of gold nanoparticles (3.

One-Dimensional Copper(I) Coordination Polymers Based on a Tridentate Thioether Ligand.

The one-dimensional copper(I) coordination polymers Cu(3){MeSi(CH(2)SMe)(3)}(2)X(3) (X = Cl, Br) and [{MeSi(CH(2)SMe)(3)}Cu(NCMe)]Y (Y = OSO(2)CF(3), BF(4), PF(6)) were readily obtained in very good to excellent yields (80-95%) by reacting CuX or [Cu(NCMe)(4)]Y, respectively, with the tridentate thioether ligand MeSi(CH(2)SMe)(3) in acetonitrile. The new complexes were characterized by a combination of analytical and spectroscopic techniques, including electrospray ionization mass spectrometry and, for the bromo and hexafluorophosphate derivatives, single-crystal X-ray diffraction. Both complexes exhibit one-dimensional chain structures with approximately tetrahedral copper centers and bridging unidentate/bidentate thioether ligands.

Tris[(alkylthio)methyl]silanes: Syntheses and Structures of Chromium, Molybdenum, and Tungsten Complexes with a Tripodal Thioether Ligand.

The first member of a new family of tripodal thioether ligands, the methyltris[(alkylthio)methyl]silanes MeSi(CH(2)SR)(3) (R = Me), has been synthesized and characterized. Reactivity studies lead to the isolation of the complete series of group 6 metal carbonyl derivatives {eta(3)-MeSi(CH(2)SMe)(3)}M(CO)(3) (M = Cr, Mo, W), whose structures have been determined by single-crystal X-ray diffraction. The three complexes are isomorphous and display distorted octahedral structures with face-capping tridentate thioether ligands.