<Emphasis Type="Italic">AB initio</Emphasis> quantum chemical study of the reaction mechanism of ethynide ion formation in the C<Subscript>2</Subscript>H<Subscript>2</Subscript>/MOH/DMSO system (M = Li,Na, K)

The reaction mechanism of the formation of alkali metal ethynides C₂H₂ + MOH → C₂HM + H₂O (M = Li, Na, K) is studied for the gas phase (MP2/6-311++G**//RHF/6-31+G*) and also with regard to the solvent effect of dimethyl sulfoxide (DMSO) included within the continuum model. Among all acetylene complexes with alkali metal hydroxides considered (C₂H₂·MOH (M = Li, Na, K)), only the complex with KOH is thermodynamically stable in DMSO solution. The formation of this structure results in activation of the acetylene molecule towards electrophilic attack. The formation of alkali metal ethynide in solution is also thermodynamically favorable only in the system with potassium hydroxide of a whole series of metals considered. Further, the ethynide ion can interact in KCCK·HOH systems.     

Coordination networks constructed with supramolecular synthon RX–CCAgn (n = 4, 5; RX = halophenyl)

Eight new silver(I) double salts: AgL¹·2AgCF₃COO (1), AgL¹·3AgNO₃ (2), 2AgL²·5AgCF₃COO·2CH₃CN·H₂O (3), 4AgL³·6AgCF₃COO·5CH₃CN (4), 4AgL⁴·6AgCF₃COO·5CH₃CN (5), 2AgL⁵·4AgCF₃COO·NC(CH₂)₄CN (6), 2AgL⁵·4AgCF₃COO·2CH₃CN (7) and AgL⁶·2CF₂(CF₂COOAg)₂·2CH₃CN (8) (L¹ = 4-iodophenylethynide; L² = 3,4-dichlorophenylethynide; L³ = 3-chlorophenylethynide; L⁴ = 3-bromophenylethynide; L⁵ = 2-chlorophenylethynide; L⁶ = 2-fluorophenylethynide) have been synthesised and characterized by X-ray crystallography. All compounds contain the silver–halophenylethynide supramolecular synthon R_X−CCAg_n (n = 4, 5). In particular, the three-dimensional supramolecular structures in 1 and 2 are stabilized by strong AgI interactions, while that in 3 is consolidated by both AgCl and van der Waals type FCl interactions. In isomorphous compounds 4 and 5, the presence of respective FCl or FBr contact contributes to the stability of the network. The silver aggregates in 6, 7 and 8 are stabilized by AgCl or AgF interactions between the ortho-halo substituent and the Ag_n basket.     

Multinuclear Silver Ethynide Supramolecular Synthons for the Construction of Coordination Networks

The invariant appearance of the μ₈ coordination mode for the C₄^2? dianion in its silver(I) complexes, with four silver(I) atoms attached to each terminal ethynide moiety, implies that the Ag₄?C?C? C?C?Ag₄ species may be considered as a new type of supramolecular synthon for the construction of 1D, 2D, and 3D coordination polymers. This Focus Review covers recent results on the synthesis and structural characterization of silver(I) arylethynide and alkylethynide complexes, which established the existence and utility of analogous polynuclear supramolecular synthons R? C?C?Ag_n (R=aryl or alkyl; n=4, 5) and Ag_n?C₂? R? C₂?Ag_n (R=p‐, m‐, o‐C₆H₄; n=4, 5). The interplay of silver–ethynide bonding, which can be classified into σ, π, and mixed (σ,π) types, with argentophilicity, π–π stacking, and other weak interactions highlights the complexity and challenge in building coordination networks of silver ethynide complexes.     

High-nuclearity silver ethynide clusters assembled with phosphonate and metavanadate precursors

Giant mixed-metal clusters have been assembled with the multinuclear silver(I) tert-butylethynide supramolecular synthon and phosphonate-functionalized oxovanadate building blocks as surface components. Various anionic species can be used as their encapsulated templates. (Picture: Ag(36) cluster anion encapsulating a chloride (sphere) and two [(O(2) )(V(2) O(6) )](4-) template anions (dark green); Ag?blue, O?red, P?yellow, V?green).