A "Push-Pull" Stabilized Phosphinidene Supported by a Phosphine-Functionalized β-Diketiminato Ligand.

The use of a bis(diphenyl)phosphine functionalized β-diketiminato ligand, [HC{(CH )C} {(ortho-[P(C H ) ] C H )N} ] (PNac), as a support for germanium(II) and tin(II) chloride and phosphaketene compounds, is described. The conformational flexibility and hemilability of this unique ligand provide a versatile coordination environment that can accommodate the electronic needs of the ligated elements. For example, chloride abstraction from [(PNac)ECl] (E=Ge, Sn) affords the cationic germyliumylidene and stannyliumylidene species [(PNac)E] in which the pendant phosphine arms associate more strongly with the Lewis acidic main group element centers, providing further electronic stabilization.

A Phosphine Functionalized β-Diketimine Ligand for the Synthesis of Manifold Metal Complexes.

A bis(diphenyl)-phosphine functionalized β-diketimine (PNac-H) was synthesized as a flexible ligand for transition metal complexes. The newly designed ligand features symmetrically placed phosphine moieties around a β-diketimine unit, forming a PNNP-type pocket. Due to the hard and soft donor atoms (N vs.

Phosphine-substituted 1,2,3-triazoles as P,C- and P,N-ligands for photoluminescent coinage metal complexes.

A series of homo- and hetero-polynuclear coinage metal complexes based on a phosphine-substituted 1,2,3-triazole system is presented. Besides the P,N-ligand 1-benzyl-4-(diphenylphosphanyl)-1H-1,2,3-triazole (LPN), the P,C-donor ligand 1-benzyl-4-(diphenylphosphanyl)-3-methyl-1H-1,2,3-triazolium (LPCH+), featuring a potential mesoionic carbene moiety, was obtained by methylation of LPN. Starting from the monogold chloride complexes AuCl(LPN/LPC), the syntheses of a heterotrinuclear Au2Cu complex as well as a digold carbene complex are described.

Samarium Polyarsenides Derived from Nanoscale Arsenic.

Zintl phases of arsenic and molecular compounds containing Zintl-type polyarsenide ions are of fundamental interest in basic and applied sciences. Unfortunately, the most obvious and reactive arsenic source for the preparation of defined molecular polyarsenide compounds, yellow arsenic As , is very inconvenient to prepare and neither storable in pure form nor easy to handle. Herein, we present the synthesis and reactivity of elemental As nanoparticles (As , d=7.

Spatially-Resolved Multiple Metallopolymer Surfaces by Photolithography.

A tetrazole-based photoligation protocol for the spatially-resolved encoding of various defined metallopolymers onto solid surfaces is introduced. By using this approach, fabrication of bi- and trifunctional metallopolymer surfaces with different metal combinations were achieved. Specifically, α-ω-functional copolymers containing bipyridine as well as triphenylphosphine ligands were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization, and subsequently metal loaded to afford metallopolymers of the widely-used metals gold, palladium, and platinum.

Synthesis and reactivity of rare-earth metal phosphaethynolates.

Over the course of the last six years, research on the synthesis and reactivity of molecular metal phosphaketenes (M-PCO) has gained increasing attention. However, lanthanide complexes of the heavier group 15 cyanate analogue PCO have not been investigated so far. Herein we present exemplar studies on the nature and reactivity of rare-earth phosphaethynolato-complexes using three characteristic representatives of the rare-earth metals: Y, Nd and Sm.

Intensely Photoluminescent Diamidophosphines of the Alkaline-Earth Metals, Aluminum, and Zinc.

The positively charged and weakly polarizable s-block metals commonly do not usually have phosphine ligands in molecular complexes. Herein, we report mono- and dinuclear small diamidophosphine complexes of the alkaline-earth metals Mg, Ca, and Sr, which were prepared from simple precursors and a phosphine-functionalized diamine ligand N,N-bis(2-(diphenyl-phosphino)phenyl)ethane-1,2-diamine (PNHNHP). The alkaline-earth metal based complexes [(PNNP)Mg] and [(PNNP)M(thf) ] (M=Ca, Sr), exhibit unusual coordination spheres and show bright fluorescence, both in the solid state and in solution.

Reactivity of bulky Ln(ii) amidinates towards P, As, and AsS.

The reduction of P4, As4 and As4S4 (realgar) with the sterically encumbered reductants [(DippForm)2Ln(thf)2] (Ln = Sm, Yb; DippForm = {(2,6-iPr2C6H3)NC(H) = N(2,6-iPr2C6H3)}-) is reported. For the first time, purely f-element containing inverse inorganic sandwich complexes [{(DippForm)2Sm}2(μ2-η4:η4-E4)] (E = P, As), featuring a π-aromatic cyclo [E4]2- middle deck, were obtained upon reaction with P4 and As4. The reaction with realgar leads to a cage disruption and the formation of the unusual species [{(DippForm)(DippForm-AsS2)}Ln(thf)].

Samarium Polystibides Derived from Highly Activated Nanoscale Antimony.

Zintl ions in molecular compounds are of fundamental interest for basic research and application. Two reactive antimony sources are presented that allow direct access to molecular polystibide compounds. These are Sb amalgam (Sb/Hg) and ultrasmall Sb nanoparticles (d=6.

SO : Closing a Gap in Sulfur Oxide Chemistry.

Just SO! The recently published synthesis of the SO dication is summarized along with the connection to the dications [C Me ] and [Cp* Fe ]. The molecular structure of the cation [C Me SO ] is shown in the figure (gray C, red O, yellow S).

Polysulfide Coordination Clusters of the Lanthanides.

The reaction of [(DippForm) Ln(thf) ] with an excess of elemental sulfur in toluene resulted in the formation of the trinuclear polysulfide coordination clusters [(DippForm) Ln S ] (Ln=Sm, Yb; DippForm=N,N'-bis(2,6-diisopropylphenyl)formamidinate). These are the first f element coordination clusters (Ln S ) with a larger polysulfide unit (n and x>2). The formation of the coordination clusters can be rationalized by the reductive cleavage of S with divalent lanthanides.

Defined tetranuclear coinage metal chains.

To force metal ions in heterometallic coinage metal complexes into preset compartments, we have synthesized a ligand with two N-heterocyclic carbenes (NHCs) separated by a methylene bridge and two bipyridine moieties tethered to each NHC moiety. By using this ligand, tetranuclear heterodimetallic gold/copper and gold/silver complexes were obtained. These complexes show an unprecedented V-shape or linear MAuM (M = Cu, Ag) configuration in the solid state.

A highly luminescent octanuclear gold(i) carbide cluster.

The ligand [{MeSiC[triple bond, length as m-dash]CC(NDipp)}Li(thf)] (Dipp = 2,6-diisopropylphenyl) was used for salt metathesis reactions with [AuCl(tht)] (tht = tetrahydrothiophene) to obtain the dinuclear alkyne functionalized bisamidinate [{MeSiC[triple bond, length as m-dash]CC(NDipp)}Au]. This compound serves as a building block for the polynuclear carbide bridged gold(i) amidinate complex [Au{μ-(η:η-C[triple bond, length as m-dash]C)}(MeSiC[triple bond, length as m-dash]CC(NDipp))(tht)], which is the first gold(i) complex with a μ-η:η carbide coordination. Both gold(i) compounds show distinct aurophilic interactions and are remarkably stable at ambient conditions.

[AgS(SCHCH Bu)(dpph)]: synthesis, crystal structure and NMR investigations of a soluble silver chalcogenide nanocluster.

With the aim to synthesize soluble cluster molecules, the silver salt of (4-(-butyl)phenyl)methanethiol [AgSCHCH Bu] was applied as a suitable precursor for the formation of a nanoscale silver sulfide cluster. In the presence of 1,6-(diphenylphosphino)hexane (dpph), the 115 nuclear silver cluster [AgS(SCHCH Bu)(dpph)] was obtained. The molecular structure of this compound was elucidated by single crystal X-ray analysis and fully characterized by spectroscopic techniques.

Double-Strand DNA Breaks Induced by Paracyclophane Gold(I) Complexes.

Gold(I) complexes of ClickPhos [2.2]paracyclophane ligands were synthesized in excellent yields and fully characterized by spectroscopic methods as well as X-ray crystallography. The complexes exhibit a rigid ligand backbone and a triazolyl moiety and were systematically studied with respect to their cytotoxic properties.

Sterically induced reductive linkage of iron polypnictides with bulky lanthanide complexes by ring-opening of THF.

Reduction of [Cp*Fe(η-E)] (E = P, As) with divalent lanthanide reagents usually leads to reduction of [Cp*Fe(η-E)] followed by a Ln-E bond formation. In contrast, by using the sterically encumbered reagent [(DippForm)Sm(thf)] (DippForm = {(2,6-PrCH)NC(H)[double bond, length as m-dash]N(2,6-PrCH)}), ring-opening of thf and reduction of the polypnictide is observed. This leads to two new 3d/4f polyphosphide or polyarsenide complexes [(DippForm)Sm(Cp*Fe)E{(CH)O}{(DippForm)Sm(thf)}], in which [(DippForm)Sm(thf)] and [Cp*Fe(η-E)] are linked by a ring-opened thf molecule and no Ln-E bond formation is observed.

Coinage Metal Complexes of Bis-Alkynyl-Functionalized N-Heterocyclic Carbenes: Reactivity, Photophysical Properties, and Quantum Chemical Investigations.

Bis-phenylpropynyl-functionalized imidazolium salts and their corresponding gold and copper N-heterocyclic carbene (NHC) complexes were prepared in order to investigate their potential application for the synthesis of heterometallic coinage metal compounds. By transmetalation reactions with different precious metal sources, including copper and silver phenylacetylides [MCCPh] (M=Cu, Ag), polynuclear compounds were obtained, which were further investigated for their photoluminescence properties. Additionally, one gold NHC complex was post-functionalized by autocatalytic hydration of the alkynyl side chains.

Synthesis and molecular structure of a spheroidal binary nanoscale copper sulfide cluster.

The reaction of copper(4-(tert-butyl)phenyl)methanethiolate [CuSCHCHBu] with bis(trimethylsilyl)sulfide S(SiMe) in the presence of triphenylphosphine PPh afforded the binary 52 nuclear copper cluster [CuS(SCHCHBu)(PPh)]. The molecular structure of this intensely red coloured nanoscale CuS mimic was established by single crystal X-ray diffraction.

Adamantyl- and Furanyl-Protected Nanoscale Silver Sulfide Clusters.

The silver salts of 1-adamantanethiol (AdSH) and furan-2-ylmethanethiol (FurCH2 SH) were successfully applied as building blocks for ligand-protected Ag2 S nanoclusters. The reaction of the silver thiolates [AgSAd]x and [AgSCH2 Fur]x with S(SiMe3 )2 and 1,5-bis(diphenylphosphino)pentane (dpppt) afforded three different clusters with 58, 94 and, 190 silver atoms. The intensely colored compounds [Ag58 S13 (SAd)32 ] (1), [Ag94 S34 (SAd)26 (dpppt)6 ] (2), and [Ag190 S58 (SCH2 Fur)74 (dpppt)8 ] (3) were structurally characterized by single-crystal X-ray diffraction and exhibit different cluster core geometries and ligand shells.

Early-Late Heterometallic Complexes of Gold and Zirconium: Photoluminescence and Reactivity.

OH functionalized triarylphosphines were used to assemble zirconocene-based metalloligands with phosphine donor sites in varying positions. These complexes were subsequently treated with different gold precursors to obtain early-late heterometallic compounds in which the metal atoms exhibit different intermetallic distances. All compounds were fully investigated by spectroscopic techniques, photoluminescence measurements and single crystal X-ray diffraction.

Photolithographic Encoding of Metal Complexes.

A platform technology for the creation of spatially resolved surfaces encoded with a monolayer consisting of different metal complexes was developed. The concept entails the light-triggered activation of a self- assembled monolayer (SAM) of UV-labile anchors, that is, phenacylsulfides, and the subsequent cycloaddition of selected diene-functionalized metal complexes at defined areas on the surface. The synthesis and characterization of the metal complexes for the UV-light assisted anchoring on the surface and a detailed study of a short-chain oligomer model system in solution confirm the high efficiency of the photoreaction.

Alkynyl-functionalized gold NHC complexes and their coinage metal clusters.

Phenylpropynyl-functionalized imidazolium salts, as well as their gold complexes, were prepared in excellent yields affording suitable starting materials for metal cluster synthesis. The reactions of these gold complexes with coinage metal phenylacetylides [M(CCPh)](x) (M = Cu, Ag) resulted in the formation of novel heterometallic hexanuclear clusters which exhibit mixed metallophillic interactions and intense white photoluminescence at low temperature.

Di- and trinuclear gold complexes of diphenylphosphinoethyl-functionalised imidazolium salts and their N-heterocyclic carbenes: synthesis and photophysical properties.

Diphenylphosphinoethyl-functionalised imidazolium salts and their silver-carbene complexes were used to synthesise a series of di- and trinuclear gold complexes through ligand exchange and transmetallation, respectively. Besides a few positively charged macrocyclic compounds with different anions (both with and without activation of the carbene function), we were able to obtain neutral polynuclear complexes by varying the gold precursor. The synthesised gold complexes show a variety of photophysical properties, including bright white photoluminescence at ambient temperature.

Realgar as a building block for lanthanide clusters: encapsulation of a copper cluster by a lanthanide cluster.

The reactions of the divalent lanthanide metallocenes [Cp*2Ln(thf)2] (Cp* = η(5)-C5Me5; Ln = Sm, Yb) with realgar (As4S4) gave the open cage tetrametallic complex [(Cp*2Sm)(Cp*Sm)3AsS3(Cp*AsS2)2(thf)3] (1) or the trimetallic cage compound [(Cp*Yb)3As2S4(Cp*AsS2)(thf)2] (2), respectively, by reductive cleavage of the inorganic cage. As result of a Cp* transfer, the novel Cp*AsS2(2-) anion is formed. Moreover, the As2S4(4-) anion, which is bound in 2, is observed for the first time in coordination chemistry.