β-Diketiminate Germylene-Supported Pentafluorophenylcopper(I) and -silver(I) Complexes [LGe(Me)(CuC6F5)n]2 (n = 1, 2), LGe[C(SiMe3)N2]AgC6F5, and {LGe[C(SiMe3)N2](AgC6F5)2}2 (L = HC[C(Me)N-2,6-iPr2C6H3]2): Synthesis and Structural Characterization

Phenylsilver - an unexpected one-dimensional coordination polymer of silver(I) tetrads

Herein we present the structures of two distinct one-dimensional coordination polymers of phenylsilver. Both polymers consist of phenylsilver tetrads inter-connected via short silver-silver contacts (either one or two). The underlying mechanism for the formation by transmetalation was validated by synthesising an analogous fluorinated derivative of phenylsilver.

Reactivity of Cyclic (Alkyl)(amino)germylene towards Copper(I) and Gold(I) Complexes

The reactions of cyclic (alkyl)(amino)germylenes (CAAGe) with copper(I) and gold(I) complexes were investigated. CAAGe (1) reacts with CuBr(SMe2 ) leading to a tetrameric germylene complex [CAAGeCuBr]4 (2), whereas CAAGe (3) undergoes Au-Cl bond insertion with LAuCl (L=phosphine or N-heterocyclic carbene) to afford germanium gold(I) complexes (5 and 6). Chlorine abstraction of 6 gives the cationic germylene gold(I) complex 7.

Synthesis and Reactivity of a Zinc Diazoalkyl Complex: [3+2] Cycloaddition Reaction with Carbon Monoxide

This work reports the synthesis, characterization, and reactivity of the first example of a well-defined zinc α-diazoalkyl complex. Treatment of zinc(I)-zinc(I) bonded compound L2 Zn2 [L=CH3 C(2,6-i Pr2 C6 H3 N)CHC(CH3 )(NCH2 CH2 PPh2 )] or zinc(II) hydride LZnH with trimethylsilyldiazomethane affords zinc diazoalkyl complex LZnC(N2 )SiMe3 . This complex liberates N2 in the presence of a nickel catalyst to form an α-zincated phosphorus ylide by reacting with the pendant phosphine. It selectively undergoes formal [3+2] cycloaddition with CO2 or CO to form the corresponding product with a five-membered heterocyclic core. Notably, the use of CO in such a [3+2] cycloaddition reaction is unprecedented, reflecting a novel CO reaction mode.

Synthesis, Characterization, and Reaction of Digermylenes

A series of digermylenes R(EGeL)₂ (L=CH[C(Me)N(Ar)]₂, Ar=2,6‐iPr₂C₆H₃; E=O, R=1,3‐C₆H₄ (1), 1,4‐C₆H₄ (2), Me₂C(CH₂)₂ (3); E=NH, R=1,4‐C₆H₄ (4), 1,4‐C₆H₁₀ (5); E=C(O)O, R=1,3‐C₆H₄ (6)) were synthesized by the reactions of L′Ge (L′=HC[C(CH₂)N(Ar)]C(Me)N(Ar), Ar=2,6‐iPr₂C₆H₃) with selected diphenols, diol, diamines, and o‐/m‐phthalic acids, respectively. Treatment of digermylene 1,3‐C₆H₄(OGeL)₂ (1) with sulfur, selenium and CuX (X=Cl, Br, I) led to the formation of 1,3‐C₆H₄[OGe(S)L]₂ (8), 1,3‐C₆H₄[OGe(Se)L]₂ (9), and (CuX)₂[1,3‐C₆H₄(OGeL)₂]₂ (X=Cl (10), Br (11), I (12)), respectively. The obtained products were characterized by melting point, elemental analysis, FT‐IR, ¹H and ¹³C NMR spectroscopy, and single‐crystal X‐ray diffraction.

Coinage Metal Complexes of Germylene and Stannylene

Group 11 metal (M = Cu, Ag, Au) complexes of heavier tetrylenes (namely, germylene and stannylene) have been studied for several years now. However, the field is mainly unexplored for their potential application either in homogeneous catalysis or in photophysical properties regardless of how the current reports allude to the rich and fascinating chemistry of group 14 elements. In this mini-review, we attempted to summarize the recent advances of heavier tetrylene-stabilized coinage metal complexes, which are majorly dominated by structure elucidation studies. This comprehensive summary intends to help researchers design and fine-tune the tetrylene ligand framework that can lead to coinage metal complexes for future applications as photoemitters in organic light-emitting diode fabrication and efficient catalysts in homogeneous catalysis.

Intramolecularly Double-Donor-Stabilized Stannylene and Its Coordination towards Ag(I) and Au(I) Centers

The intramolecularly double-donor-stabilized stannylene 1 has been synthesized from the salt-metathesis reaction between two equivalents of lithium pyridine ene-amide L1 and SnCl₂ . Compound 1 exhibits dipolar behavior when reacted with B(C₆ F₅ )₃ leading to the zwitterionic compound 2. The reaction of 1 with one equivalent and 0.5 equivalent of AgOTf (OTf=trifluoromethane sulfonate) result in the formation of a stannylene-AgOTf complex 3 and a homoleptic distannylene-silver ionic complex 4, respectively. Analogous to complex 4, the gold(I) complex 5 has been synthesized from the reaction between two equivalents of 1 and 0.5 equivalent of AuCl.SMe₂ /Me₃ SiOTf. Complex 5 is the first example of homoleptic stannylene-Au(I) ionic complex among the very scarce reports on stannylene-gold(I) coordination complexes. All compounds have been structurally characterized using single crystal X-ray crystallography. Solution-state characterization have been performed using multinuclear NMR techniques. Detailed DFT calculations on the optimized geometries 1 o, 3 o-5 o reveal the change in sp- hybridization on the pyramidal Sn(II) center upon metal coordination and their bonding overlaps.

Polynuclear organometallic clusters: synthesis, structure, and reactivity studies

This feature article highlights our recent advances in the controllable synthesis of carbon-centered polynuclear organometallic clusters: from synthesis to transformation, reactivity and mechanism.

Undiscovered Potential: Ge Catalysts for Lactide Polymerization

Polylactide (PLA) is a high potential bioplastic that can replace oil-based plastics in a number of applications. To date, in spite of its known toxicity, a tin catalyst is used on industrial scale which should be replaced by a benign catalyst in the long run. Germanium is known to be unharmful while having similar properties as tin. Only few germylene catalysts are known so far and none has shown the potential for industrial application. We herein present Ge complexes in combination with zinc and copper, which show amazingly high polymerization activities for lactide in bulk at 150 °C. By systematical variation of the complex structure, proven by single-crystal XRD and DFT calculations, structure-property relationships are found regarding the polymerization activity. Even in the presence of zinc and copper, germanium acts as the active site for polymerizing probably through the coordination-insertion mechanism to high molar mass polymers.

Synthesis and Complexation of a Free Germanide Bearing a Tridentate N-Heterocyclic Substituent

The tris-N-heterocycle germanide (tmim)Ge^- (1) (tmimH₃ = tris(3-methylindol-2-yl)methane) was synthesized by nucleophilic substitution for the tmim^3- trianion on GeCl₂·dioxane. In combination with the previously reported (tmim)Si^- and (tmim)P analogues, it provides a convenient model for investigating the influence of the central atom on the properties of isoelectronic ligands. Complexation of the germanide (tmim)Ge^- to CuCl resulted in the dimeric chloro cuprate [(tmim)GeCu(μ-Cl)]₂ ^2-, which is prone to dissociation in MeCN to form the neutral, solvated germylcopper (tmim)GeCu(NCMe)₃. The reaction of 1 with Fe₂(CO)₉ afforded the germyl iron tetracarbonyl [(tmim)GeFe(CO)₄]^-. Analysis of the ν̃(CO) infrared absorption bands in this complex indicates that the combined electron donating and accepting properties of 1 are found in between those of (tmim)P and (tmim)Si^-. In contrast to (tmim)Si^-, (tmim)Ge^- is reluctant to coordinate to FeCl₂, likely because of its softer Lewis base character. Key structural features of the ligands and complexes reflect changes in their electronic properties. In particular, the N-Ge-N angles increase upon coordination to a metal fragment, suggesting increasing hybridization of the Ge s- and p-orbitals. These findings will be useful in further understanding low-valent heavier group 14 complexes in organometallic chemistry.

Linear Copper Complex Arrays as Versatile Molecular Strings: Syntheses, Structures, Luminescence, and Magnetism

The defined linear arrangement of metal atoms in discrete coordination complexes or polymers is still one of the most intriguing challenges in synthetic chemistry. These chain arrangements are of fundamental importance, because of their potential applications as molecular wires and single molecule magnets (SMM) in microelectronic devices on a molecular scale. Oligonuclear Group 11 metal complexes with suitable bridging ligands, specifically those that are based on copper as the first choice of a cheap precursor coinage metal, are of particular interest in this regard. This is due to the superior luminescence properties of these linear clusters that often show d¹⁰ ⋅⋅⋅d¹⁰ interactions in their molecular structures. The combination of Cu^I with heavier coinage metal ions results in tunable emissive arrays that are also stimuli-responsive. Thus, both linear multinuclear Cu^I and linear heteropolymetallic Cu^I /Ag^I as well as Cu^I /Au^I clusters are excellent candidates for applications in molecular/organic light-emitting devices (OLEDs). Alternatively, paramagnetic multinuclear cupric arrays are prominent as potential molecular wires with enhanced magnetic properties through multiple coupled d⁹ centers. This Review covers the whole range of linear multinuclear assemblies of cuprous and cupric ions in complexes and coordination polymers, their syntheses, photophysical behavior, and magnetic properties. Moreover, recent advances in the rapidly progressing field of hetero-Cu^I /Ag^I and Cu^I /Au^I molecular strings are also discussed.

Germylene stabilized group 12 metal complexes and their reactivity with chalcogens

This manuscript reports the first examples of germylene stabilized cadmium complexes 3, 6, and 7, and novel germylene zinc complexes 2 and 5.

Synthesis, structures, photophysical and catalytic properties of benzothienyl iridium(III) complexes

Bisbenzothienyl iridium(III) complexes, [Ir(bt)2(PR3)]X (bt: 2-phenylbenzo[ d]thiazole, R = n-Bu or Ph, X = OTf, BF4 or SbF6) are reported, two of which, (R = n-Bu or Ph, X = OTf), have been characterised by X-ray crystallography. The complexes are thermally stable and their photophysical properties are presented, together with their catalytic activity in the “borrowing hydrogen reaction” of alcohols with amines.

Luminescent aryl–group eleven metal complexes

This perspective highlights the recent developments in the study of the photoluminescent properties of aryl–group eleven complexes. Related properties and applications such as electroluminescence, triboluminescence, mechanochromism, luminescent liquid crystals, low molecular weight gelators and photocatalysts are also discussed.

Coordination Chemistry of Cyclic Disilylated Germylenes and Stannylenes with Group 11 Metals

Reactions of Et₃P adducts of bissilylated germylenes and stannylenes with gold, silver, and copper cyanides led to cyanogermyl or -stannyl complexes of the respective metals. In the course of the reaction the phosphine moved to the metal, while the cyanide migrated to the low-coordinate group 14 element. The respective gold complexes were found to be monomeric, whereas the silver and copper complexes exhibited a tendency to dimerize in the solid state. Attempts to abstract the phosphine ligand with B(C₆F₅)₃ led only to the formation of adducts with the borane coordinating to the cyanide nitrogen atom.

Synthesis, structure and a nucleophilic coordination reaction of Germanetellurones

A germylene germanetellurone adduct L(Cp)GeTe(GeCl₂), a pentafluorophenyl gold(i) germanethione and germaneselone compounds L(Me)GeE(AuC₆F₅) (E = S and Se) are herein reported.

Dinuclear copper complexes: coordination of Group 14 heteroborates

The dinuclear copper(i) complex [Cu₂(μ-dmapm)(CH₃CN)₂][BF₄]₂ was reacted with Group 14 heteroborates. Four different coordination motives have been characterized.