Homoleptic transition metal acetylides

Crystal Structure of the Monocarborane Magnesium(II) Acetylide and Its Use in the Synthesis of α,β-Unsaturated Ketones

We report the first crystal structure of heteroleptic Grignard reagent 2 based on the carborane endo/exo dianion [CB11H11-12-C≡C]2-. Full characterization reveals a rare coordination pattern and affirms the bimetallic nature. Navigating the reactivity landscape, we unlock the potential of 2 in nucleophilic addition with ketones to afford propargylic alcohols 3, renowned for their synthetic versatility and potential biological activities, and unveil the Meyer-Schuster rearrangement, yielding α,β-unsaturated carbonyl compounds 4. This narrative of synthesis, characterization, and reactivity opens new horizons for carborane chemistry, offering avenues for innovation and facile functionalization of carborane scaffolds.

A 66-Nuclear All-Alkynyl Protected Peanut-Shaped Silver(I)/Copper(I) Heterometallic Nanocluster: Intermediate in Copper-Catalyzed Alkyne-Azide Cycloaddition

Ligand-protected heterometallic nanoclusters in contrast to homo-metal counterparts show more broad applications due to the synergistic effect of hetero-metals but their controllable syntheses remain a challenge. Among heterometallic nanoclusters, monovalent Ag-Cu compounds are rarely explored due to much difference of Ag(I) and Cu(I) such as atom radius, coordination habits, and redox potential. Encouraged by copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction, comproportionation reaction of Cu(II)X2 and Cu(0) in the presence of (PhC≡CAg)n complex and molybdate generated a core-shell peanut-shaped 66-nuclear Ag(I)-Cu(I) heterometallic nanocluster, [(Mo4O16)2@Cu12Ag54(PhC≡C)50] (referred to as Ag54Cu12). The structure and composition of Ag-Cu heterometallic nanocluster are fully characterized. X-ray single crystal diffraction reveals that Ag54Cu12 has a peanut-shaped silver(I)/copper(I) heterometallic nanocage protected by fifty phenylacetylene ligands in µ3-modes and encapsulated two mutually twisted tetramolybdates. Heterometallic nanocage contains a 54-Ag-atom outer ellipsoid silver cage decorated by 12 copper inside wall. Nanosized Ag54Cu12 is a n-type narrow-band-gap semiconductor with a good photocurrent response. Preliminary experiments demonstrates that Ag54Cu12 itself and activated carbon supported Ag54Cu12/C are effective catalysts for 1,3-dipole cycloaddition between alkynes and azides at ambient conditions. The work provides not only a new synthetic route toward Ag(I)-Cu(I) nanoclusters but also an important heterometallic intermediate in CuAAC catalytic reaction.

Tetracopper σ-Bound μ-Acetylide and -Diyne Units Stabilized by a Naphthyridine-based Dinucleating Ligand

Reactions of a dicopper(I) tert-butoxide complex with alkynes possessing boryl or silyl capping groups resulted in formation of unprecedented tetracopper(I) μ-acetylide/diyne complexes that were characterized by NMR and UV/Vis spectroscopy, mass spectrometry and single-crystal X-ray diffraction. These compounds possess an unusual μ4 -η1 :η1 :η1 :η1 coordination mode for the bridging organic fragment, enforced by the rigid and dinucleating nature of the ligand utilized. Thus, the central π system remains unperturbed and accessible for subsequent reactivity and modification. This has been corroborated by addition of a fifth copper atom, giving rise to a pentacopper acetylide complex. This work may provide a new approach by which metal-metal cooperativity can be exploited in the transformation of acetylide and diyne groups to a variety of substrates, or as a starting point for the controlled synthesis of copper(I) alkyne-containing clusters.

Organolithium aggregation as a blueprint to construct polynuclear lithium nickelate clusters

By exploiting the high aggregation of aliphatic lithium acetylides, here we report the synthesis and structural analysis of polynuclear lithium nickelate clusters in which up to 10 equivalents of organolithium can co-complex per Ni(0) centre. Exposure of the Ni(0)-ate clusters to dry air provides an alternative route to homoleptic Ni(II)-ates.

Osmathiazole Ring: Extrapolation of an Aromatic Purely Organic System to Organometallic Chemistry

An osmathiazole skeleton has been generated starting from the cation of the salt [OsH(OH)(≡CPh)(IPr)(PiPr3)]OTf (1; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CF3SO3) and thioacetamide; its aromaticity degree was compared with that of thiazole, and its aromatic reactivity was confirmed through a reaction with phenylacetylene. Salt 1 reacts with the thioamide to initially afford the synthetic intermediate [OsH{κ2-N,S-[NHC(CH3)S]}(≡CPh)(IPr)(PiPr3)]OTf (2). Thioamidate and alkylidyne ligands of 2 couple in acetonitrile at 70 °C, forming a 1:1 mixture of the salts [OsH{κ2-C,S-[C(Ph)NHC(CH3)S]}(CH3CN)(IPr)(PiPr3)]OTf (3) and [Os{κ2-C,S-[CH(Ph)NHC(CH3)S]}(CH3CN)3(IPr)]OTf (4). Treatment of 3 with potassium tert-butoxide produces the NH-deprotonation of its five-membered ring and gives OsH{κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (5). The osmathiazole ring of 5 is slightly less aromatic than the osmathiazolium cycle of 3 and the purely organic thiazole. However, it is more aromatic than related osmaoxazoles and osmaoxazoliums. There are significant differences in behavior between 3 and 5 toward phenylacetylene. In acetonitrile, the cation of 3 loses the phosphine and adds the alkyne to afford [Os{η3-C3,κ1-S-[CH2C(Ph)C(Ph)NHC(CH3)S]}(CH3CN)2(IPr)]OTf (6), bearing a functionalized allyl ligand. In contrast, the osmathiazole ring of 5 undergoes a vicarious nucleophilic substitution of hydride, by acetylide, via the dihydride OsH2(C≡CPh){κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (7), which releases H2 to yield Os(C≡CPh){κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (8).

Self-Assembly of Molecular Trefoil Knots Featuring Pentadecanuclear Homoleptic AuI -, AuI /AgI -, or AuI /CuI -Alkynyl Coordination

Metal-free and metal-containing molecular trefoil knots are fascinating ensembles that are usually covalently assembled, the latter requiring the rational design of di- or multidentate/multipodal ligands as connectors. In this work, we describe the self-assembly of pentadecanuclear Au^I trefoil knots [Au₁₅ (C≡CR)₁₅ ] from monoalkynes HC≡CR (R=9,9-X₂ -fluorenyl with X=nBu, n-hexyl) and [Au^I (THT)Cl]. Hetero-bimetallic counterparts [Au₉ M₆ (C≡CR)₁₅ ] (M=Cu/Ag) were self-assembled by reactions of [Au₁₅ (C≡CR)₁₅ ] with [Cu(MeCN)₄ ]⁺ /AgNO₃ and HC≡CR. The type of pentadecanuclear trefoil knots described herein is characterized by X-ray crystallography, 2D NMR and HR-ESI-MS. [Au₉ Cu₆ (C≡CR)₁₅ ] is relatively stable in hexane; its excited state properties were investigated. DFT calculations revealed that non-covalent metal-metal and metal-ligand interactions, together with longer alkyl chain-strengthened inter-ligand dispersion interactions, govern the stability of the trefoil knot structures.

Alkynyl Ligands as Building Blocks for the Preparation of Phosphorescent Iridium(III) Emitters: Alternative Synthetic Precursors and Procedures

Alkynyl ligands stabilize dimers [Ir(μ-X)(3b)₂]₂ with a cis disposition of the heterocycles of the 3b ligands, in contrast to chloride. Thus, the complexes of this class—cis-[Ir(μ₂-η²-C≡CPh){κ²-C,N-(C₆H₄-Isoqui)}₂]₂ (Isoqui = isoquinoline) and cis-[Ir(μ₂-η²-C≡CR){κ²-C,N-(MeC₆H₃-py)}₂]₂ (R = Ph, ^tBu)—have been prepared in high yields, starting from the dihydroxo-bridged dimers trans-[Ir(μ-OH){κ²-C,N-(C₆H₄-Isoqui)}₂]₂ and trans-[Ir(μ-OH){κ²-C,N-(MeC₆H₃-py)}₂]₂ and terminal alkynes. Subsequently, the acetylide ligands have been employed as building blocks to prepare the orange and green iridium(III) phosphorescent emitters, Ir{κ²-C,N-[C(CH₂Ph)Npy]}{κ²-C,N-(C₆H₄-Isoqui)}₂ and Ir{κ²-C,N-[C(CH₂R)Npy]}{κ²-C,N-(MeC₆H₃-py)}₂ (R = Ph, ^tBu), respectively, with an octahedral structure of fac carbon and nitrogen atoms. The green emitter Ir{κ²-C,N-[C(CH₂^tBu)Npy]}{κ²-C,N-(MeC₆H₃-py)}₂ reaches 100% of quantum yield in both the poly(methyl methacrylate) (PMMA) film and 2-MeTHF at room temperature. In organic light-emitting diode (OLED) devices, it demonstrates very saturated green emission at a peak wavelength of 500 nm, with an external quantum efficiency (EQE) of over 12% or luminous efficacy of 30.7 cd/A.

Acetylide ligands have been employed as building blocks to prepare orange and green iridium(III) phosphorescent emitters, with an octahedral structure of fac carbon and nitrogen atoms. In OLED devices, the emitter Ir{κ²-C,N-[C(CH₂^tBu)Npy]}{κ²-C,N-(MeC₆H₃-py)}₂ demonstrates very saturated green emission at a peak wavelength of 500 nm, with a luminous efficacy of 30.7 cd/A.

An asymmetric Pt diimine acetylide complex providing unique luminescent multinuclear sandwich complexes with Cu salts

The formation and photophysical properties of two types of sandwich complexes supported by asymmetric Pt complex units having two different acetylide moieties are reported. The asymmetric Pt complex unit was obtained via acetylide metathesis reaction between two types of symmetric Pt complexes. The reversible acetylide exchange reaction was effectively suppressed by the incorporation of Cu ions to give unique chiral Pt₄Cu₃ and achiral Pt₂Cu₄Br₄ sandwich complexes. The sandwich complexes exhibited moderate photoluminescence in the solid state, and their photophysical properties depended on the sandwich structures. These results suggest that asymmetric Pt complex units can give remarkable assembled structures by the concerted effect of labile coordination bonds and weak noncovalent interactions.

Recent advances in polyoxometalate-based metal-alkynyl clusters

This paper focuses on the recent advances in polyoxometalate-based metal-alkynyl clusters.

Isolable acetylene complexes of copper and silver

Copper and silver play important roles in acetylene transformations but isolable molecules with acetylene bonded to Cu(i) and Ag(i) ions are scarce. This report describes the stabilization of π-acetylene complexes of such metal ions supported by fluorinated and non-fluorinated, pyrazole-based chelators. These Cu(i) and Ag(i) complexes were formed readily in solutions under an atmosphere of excess acetylene and the appropriate ligand supported metal precursor, and could be isolated as crystalline solids, enabling complete characterization using multiple tools including X-ray crystallography. Molecules that display κ²-or κ³-ligand coordination modes and trigonal planar or tetrahedral metal centers have been observed. Different trends in coordination shifts of the acetylenic carbon resonance were revealed by ¹³C NMR spectroscopy for the Cu(i) and Ag(i) complexes. The reduction in acetylene Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> _{C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C} due to metal ion coordination is relatively large for copper adducts. Computational tools were also used to quantitatively understand in detail the bonding situation in these species. It is found that the interaction between the transition metal fragment and the acetylene ligand is significantly stronger in the copper complexes, which is consistent with the experimental findings. The CC distance of these copper and silver acetylene complexes resulting from routine X-ray models suffers due to incomplete deconvolution of thermal smearing and anisotropy of the electron density in acetylene, and is shorter than expected. A method to estimate the CC distance of these metal complexes based on their experimental _CC is also presented.

Gaseous acetylene can be trapped on copper(i) and silver(i) sites supported by pyrazole-based scorpionates to produce isolable molecules for detailed investigations and the study of metal-acetylene bonding.

A Photoluminescent Ag10 Cu6 Cluster Stablized by a PNNP Ligand and Phenylacetylides Selectively and Reversibly Senses Ammonia in Air and Water

A photoluminescent bimetallic cluster [Ag₁₀ Cu₆ (bdppthi)₂ (C≡CPh)₁₂ (MeOH)₂ (H₂ O)](ClO₄ )₄ (1, bdppthi=N,N'-bis(diphenylphosphanylmethyl)-tetrahydroimidazole} was synthesized from the PNNP type ligand bdppthi generated in-situ. Upon excitation at 365 nm, 1 exhibited strong phosphorescent emission at 630 nm, which was selectively quenched by NH₃ in air or water. The sensing of NH₃ was rapid and recoverable, with detection limits of 53 ppm (v/v) in N₂ and 21 μmol/L (0.36 ppm, w/w) for NH₃  ⋅ H₂ O in water. Cluster 1 could potentially serve as a bifunctional chemical sensor for the efficient detection of ammonia in waste-gas and waste-water.

Keep it tight: a crucial role of bridging phosphine ligands in the design and optical properties of multinuclear coinage metal complexes

Copper subgroup metal ions in the +1 oxidation state are classical candidates for aggregation via non-covalent metal-metal interactions, which are supported by a number of bridging ligands. The bridging phosphines, soft donors with a relatively labile coordination to coinage metals, serve as convenient and essential components of the ligand environment that allow for efficient self-assembly of discrete polynuclear aggregates. Simultaneously, accessible and rich modification of the organic spacer of such P-donors has been used to generate many fascinating structures with attractive photoluminescent behavior. In this work we consider the development of di- and polynuclear complexes of M(i) (M = Cu, Ag, Au) and their photophysical properties, focusing on the effect of phosphine bridging ligands, their flexibility and denticity.

Novel luminescent homo/heterometallic platinum(ii) alkynyl complexes based on Y-shaped pyridyl diphosphines

A series of dinuclear platinum(ii) alkynyl complexes [Pt2L2(C[triple bond, length as m-dash]CC6H4R-4)4] (R = H 1, CH32, But3) and unusual tetranuclear Pt(ii)-Ag(i) clusters [Pt2Ag2L(C[triple bond, length as m-dash]CC6H4R-4)6] (R = H, 4; CH3, 5; But, 6), together with novel polymer crystals [Pt2Ag2L(C[triple bond, length as m-dash]CC6H5)6]∞ ([4]∞), were synthesized by a self-assembly reaction between [NBu4]2[Pt(C[triple bond, length as m-dash]CC6H4-R-4)4] and [Ag6L6]6+ (L = 4-(3,5-(diphenylphosphine)phenyl)pyridine). These complexes were characterized by using a range of spectroscopic techniques and complexes 1, 3, 5, and [4]∞ were analysed by X-ray crystallography. Each platinum atom of the Pt(ii)-Ag(i) clusters shows an unusual asymmetric distorted square planar geometry with three alkynyl groups and one bridging L phosphorus atom. Dinuclear complexes 1-3 demonstrate solid-state weak blue luminescence, while tetranuclear Pt(ii)-Ag(i) clusters 4-6 show intense blue-green or yellow-green emission. Furthermore, the crystalline samples of polymer [4]∞ display bright yellow emission (518 nm) that is significantly red-shifted as compared to monomer crystal 4.

The 12-ethynylmonocarba-closo-dodecaborate anion as a versatile ligand for Cu(i) alkyne and heterobimetallic Cu(i)/M(ii) (M = Pd, Pt) alkynide complexes

The anionic 12-ethynyl-monocarba-closo-dodecaborate cluster is employed as a ligand for the preparation of Cu(i) and heterobimetallic Cu(i)/Pd(ii) or Cu(i)/Pt(ii) complexes.

Acetylene and terminal alkyne complexes of copper(i) supported by fluorinated pyrazolates: syntheses, structures, and transformations

A variety of isolable, 2 : 1 and 1 : 1 copper(i)–alkyne complexes of containing pyrazolate ligand supports are presented as well as the copper pyrazolate mediated acetylenic C–H and alkyne CC bond functionalizations.

Acetylene in Organic Synthesis: Recent Progress and New Uses

Recent progress in the leading synthetic applications of acetylene is discussed from the prospect of rapid development and novel opportunities. A diversity of reactions involving the acetylene molecule to carry out vinylation processes, cross-coupling reactions, synthesis of substituted alkynes, preparation of heterocycles and the construction of a number of functionalized molecules with different levels of molecular complexity were recently studied. Of particular importance is the utilization of acetylene in the synthesis of pharmaceutical substances and drugs. The increasing interest in acetylene and its involvement in organic transformations highlights a fascinating renaissance of this simplest alkyne molecule.

Cationic tri(ferrocenecarbonitrile)silver(I)

The synthesis of the tri-coordinated ferrocenecarbonitrile silver(I) complex [Ag(N≡CFc)3]OTf (3) is reported. Its electrochemical behavior shows that the three ferrocenyl units are oxidized in a very close potential range. In addition, the molecular structure of 3 in the solid state is discussed, showing that silver(I) is exclusively coordinated by three ferrocenecarbonitrile molecules.

Label-free sensitive luminescence biosensor for immunoglobulin G based on Ag6Au6 ethisterone cluster-estrogen receptor α aggregation and graphene

A specific and label-free "on-off-on" luminescence biosensor based on a novel heterometallic cluster [Ag₆Au₆(ethisterone)₁₂]-estrogen receptor α (Ag₆Au₆Eth-ERα) aggregation utilizing graphene oxide (GO) as a quencher to lead a small background signal was firstly constructed to detect immunoglobulin G (IgG) with a simple process and high selectivity. The efficient photoluminescent (PL) Ag₆Au₆Eth-ERα aggregation is strongly quenched by GO. In the presence of IgG, the PL of this system will be restored, and perceivable by human eyes under UV lamp excitation (365 nm). The quenching mechanism of GO on Ag₆Au₆Eth-ERα and enhancement mechanism of IgG on Ag₆Au₆Eth-ERα-GO were investigated in detail. Under the optimum conditions, the biosensor for high sensitive IgG detection expressed a wider linear range of 0.0078-10 ng/mL and a lower detection limit of 0.65 pg/mL with good stability and repeatability, which provided a new approach for label-free IgG detection.

U- to Z-shape isomerization in a Pt2Ag2 framework containing pyridyl-NHC ligands

A highly twisted U-shaped Pt₂Ag₂ complex bearing pyridyl–NHC ligands showed isomerization to Z-shaped conformations via an intermolecular process. ¹H NMR experiments revealed that the isomerization reached U : Z = 2 : 1 ratio in a thermodynamic equilibrium state.

Synthesis of a palladium acetylide-based tubular microporous polymer monolith via a self-template approach: a potential precursor of supported palladium nanoparticles for heterogeneous catalysis

A monolithic, palladium acetylide-based conjugated microporous polymer, Pd-CMP, was synthesized from a palladium dichloride and a trialkyne. The polymerization proceeded in two different ways, the dehydrohalogenation reaction between the alkyne and the palladium halide and the homocoupling reaction of the alkyne. Pd-CMP had a rigid hollow tubular structure. The in situ formed crystalline triethylammonium chloride (TEACl) rod played a critical role in the formation of the tubular morphology as a template. Through the attachment of the polymer particles to the surface of the rod and their reactions with soluble alkynes, a core–shell structure with a TEACl core and a polymer shell formed. The TEACl core was removed by washing with methanol to yield a hollow polymer tube. Pd-CMP showed a hierarchical pore structure and reversible compressibility. Supported Pd nanoparticles were prepared by one-step thermolysis of Pd-CMP as a heterogeneous catalyst. The average diameters of NPs in the products thermolyzed at 300 (Pd-CMP₃₀₀) and 500 °C (Pd-CMP₅₀₀) were 2.6 and 4.1 nm, respectively. Pd-CMP₃₀₀ was used in the heterogeneous catalysis of the 4-nitrophenol reduction reaction and Suzuki–Miyaura coupling between iodobenzene and phenylboronic acid. The reaction yields were higher than 95%. The catalyst could be used for a flow reaction and easily recycled without significant activity loss.

A monolithic palladium acetylide-based tubular microporous polymer was synthesized as a promising precursor of a palladium heterogeneous catalyst.

Novel chloride-centered Ag18 clusters featuring a cuboctahedral Ag12 skeleton

Two novel chloride-centered Ag₁₈ clusters with the same framework but different supporting phosphines are synthesized by the reaction of PhC[triple bond, length as m-dash]CAg, AgSbF₆, PPh₃ (or P(p-Tol)₃), and NaBH₄ in CH₂Cl₂, followed by the addition of PhC[triple bond, length as m-dash]CH and NEt₃. The inner twelve Ag atoms of these two clusters are arranged in a rare cuboctahedral structure, which can be rationalized by considering a ligand effect. Through careful analysis, we find that the central chloride arises from a generally ignored but nonetheless existing reaction between CH₂Cl₂ and NEt₃, which is well recognized as the Menshutkin reaction. This research provides insights into the dependence of the cluster structure on the nature of the ligand and into the cluster formation mechanism of the Menshutkin reaction.

Perfluoroalkyltricyanoborate and Perfluoroalkylcyanofluoroborate Anions: Building Blocks for Low-Viscosity Ionic Liquids

The potassium perfluoroalkyltricyanoborates K[C_n F_2 n+1 B(CN)₃ ] [n=1 (1 d), 2 (2 d)] and the potassium mono(perfluoroalkyl)cyanofluoroborates K[C_n F_2 n+1 BF(CN)₂ ] [n=1 (1 c), 2 (2 c)] and [C_n F_2 n+1 BF₂ (CN)]^- [n=1 (1 b), 2 (2 b), 3 (3 b), 4 (4 b)] are accessible with perfect selectivities on multi-gram scales starting from K[C_n F_2 n+1 BF₃ ] and Me₃ SiCN. The K⁺ salts are starting materials for the preparation of salts with organic cations, for example, [EMIm]⁺ (EMIm=1-ethyl-3-methylimidazolium). These [EMIm]⁺ salts are hydrophobic room-temperature ionic liquids (RTILs) that are thermally, chemically and electrochemically very robust, offering electrochemical windows up to 5.8 V. The RTILs described herein, exhibit very low viscosities with a minimum of 14.0 mPa s at 20 °C for [EMIm]1 c, low melting points down to -57 °C for [EMIm]2 b and extraordinary high conductivities up to 17.6 mS cm^-1 at 20 °C for [EMIm]1 c. The combination of these properties makes these ILs promising materials for electrochemical devices as exemplified by the application of selected RTILs as component of electrolytes in dye-sensitised solar cells (DSSCs, Grätzel cells). The efficiency of the DSSCs was found to increase with a decreasing viscosity of the neat ionic liquid. In addition to the spectroscopic characterisation, single crystals of the potassium salts of the anions 1 b-d, 2 d, 3 b and 4 c as well as of [nBu₄ N]2 c have been studied by X-ray diffraction.

Gas phase anion photoelectron spectroscopy and theoretical investigation of gold acetylide species

We conducted gas phase anion photoelectron spectroscopy and density functional theory studies on a number of gold acetylide species, such as AuC₂H, AuC₂Au, and Au₂C₂H. Based on the photoelectron spectra, the electron affinities of AuC₂H, AuC₂Au, and Au₂C₂H are measured to be 1.54(±0.04), 1.60(±0.08), and 4.23(±0.08) eV, respectively. The highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of AuC₂H and AuC₂Au are measured to be about 2.62 and 2.48 eV, respectively. It is interesting that photoelectron spectra of AuC₂H^- and AuC₂Au^- display similar spectral features. The comparison of experimental and theoretical results confirms that the ground-state structures of AuC₂H^-, AuC₂Au^-, and their neutrals are all linear with Au-C≡C-H and Au-C≡C-Au configurations. The similar geometric structures, spectral features, HOMO-LUMO gaps, and chemical bonding between AuC₂H^-/0 and AuC₂Au^-/0 demonstrate that Au atom behaves like H atom in these species. The photoelectron spectrum of Au₂C₂H^- shows that Au₂C₂H has a high electron affinity of 4.23(±0.08) eV, indicating Au₂C₂H is a superhalogen. Further, we found an unusual similarity between the terminal Au atom of Au₂C₂H^- and the iodine atom of IAuC₂H^-.

Assembly of high-symmetry silver(i) alkyl-1,3-diynyl cluster complexes via core transformation

Supramolecular precursors [(R–CC–CC)Ag]₄(PPh₃)₄ (R = iPr and chx) are employed to construct three iso-structural silver(i) alkyl-1,3-diynyl cluster complexes that bear the same novel trigonal bipyramidal Ag₅ core.

Phosphorescent platinum(ii) alkynyls end-capped with benzothiazole units

Phosphorescent platinum(ii) alkynyls. Phosphorescent trans-bis(alkynyl) bis(phosphine) or bis(cyanide) Pt^II derivatives (1–4) based on the 2-phenylbenzothiazole unit have been prepared. The negative solvatochromic behavior of 4 has been analyzed by the Kamlet–Taft solvent scale and the Gutmann's acceptor numbers. The optical properties were addressed by TD and DFT calculations on 2 and 4.