A Heterobimetallic Approach To Stabilize the Elusive Disulfur Radical Trianion (“Subsulfide”) ${{\rm S}{{{{\bullet}}3- \hfill \atop 2\hfill}}}$

A unique heterobimetallic disulfur monoradical, complex 2 , with a diamond‐shaped {NiS₂Pt} core has been synthesized by two‐electron reduction of a supersulfido‐(nacnac)nickel(II) complex (nacnac=β‐diketiminato) with [Pt(Ph₃P)₂(η²‐C₂H₄)] as a platinum(0) source and isolated in 82 % yield. Strikingly, the results of DFT calculations in accordance with spectroscopic (EPR, paramagnetic NMR) and structural features of the complex revealed that the bonding situation of the S₂ ligand is between the elusive “half‐bonded” S₂ radical trianion (${{\rm S}{{{{\bullet}}3- \hfill \atop 2\hfill}}}$ ) and two separated S^2? ligands. Accordingly, the Ni^II center is partially oxidized, whereas the Pt^II site is redox innocent. The complex can be reversibly oxidized to the corresponding Ni,Pt‐disulfido monocation, compound 3 , with a S? S single bond, and reacts readily with O₂ to form the corresponding superoxonickel(II) and disulfidoplatinum(II) ( 4 ) complexes. These compounds have been isolated in crystalline form and fully characterized, including IR and multi‐nuclear NMR spectroscopy as well as ESI mass spectrometry. The molecular structures of compounds 2 – 4 have been confirmed by single‐crystal X‐ray crystallography.     

Synthese,Kristallstrukturen und Absorptionsspektren der neuen „Cupriosilicate”︁: K6[CuSi2O8] und Rb4[CuSi2O7]

Synthesis, Crystal Structures, and Absorption Spectra of the New “Cupriosilicates”: K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] were obtained by annealing intimate mixtures of K₂O and Rb₂O, respectively, CuO and SiO₂ in sealed Ag cylinders at 500°C as transparent greenish-blue single crystals. The structure solution (IPDS-data Mo Kα; K₆[CuSi₂O₈]: 1292 F²(hkl), R1 = 0.059; wR2 = 0.103 and Rb₄[CuSi₂O₇]: 763 F²(hkl), R1 = 0.049; wR2 = 0.114) confirms the space group P1 for both compounds. K₆[CuSi₂O₈]: a = 619.4(2); b = 665.5(2); c = 753.0(2) pm; α = 83.66(3); β = 87.71(3); γ = 70.19(3)°; Z = 1. Rb₄[CuSi₂O₇]: a = 631.9(9); b = 707.5(10); c = 715.2(6) pm; α = 114.2(1); β = 100.7(1); γ = 107.9(1)°; Z = 1. The Madelung Part of the Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these calculated via Mean Effective Ionic Radii, MEFIR, are given. The absorption spectra of K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] are discussed in terms of the Angular Overlap Model, AOM.     

Collision-induced dissociation of negative ions in the gas phase: [Aryl S]−, [aryl SO]− and [aryl SO2]−

Collision-induced dissociation of the ions [ArS]^?, [ArSO]^? and [ArSO₂]^? has uncovered a rich and varied ion chemistry. The major fragmentations of [ArS]^? are complex and occur without prior ring hydrogen scrambling: for example, [C₆H₅S]^?→[C₂HS]^? and [HS]^?; [p-CD₃C₆H₄S]^?→[C₆H₄S]^?˙, [CD₃C₄S]^? and [C₂HS]^?. In contrast, all decompositions of [C₆H₅CH₂S]^? are preceded by specific benzylic and phenyl hydrogen interchange reactions. [ArSO₂]^? and [ArSO₂]^? ions undergo rearrangement, e.g. [C₆H₅SO]^?→[C₆H₅O]^? and [C₆H₅S]^?; [C₆H₅SO₂]^?→[C₆H₅O] ^?. The ion [C₆H₅CH₂SO]^? eliminates water, this decomposition is preceded by benzylic and phenyl hydrogen exchange.     

Investigation of Large Polychloride Anions: [Cl11]−, [Cl12]2−, and [Cl13]−

For decades the chemistry of polyhalides was dominated by polyiodides and more recently also by an increasing number of polybromides. However, apart from a few structures containing trichloride anions and a single report on an octachloride dianion, [Cl₈]^2?, polychlorine compounds such as polychloride anions are unknown. Herein, we report on the synthesis and investigation of large polychloride monoanions such as [Cl₁₁]^? found in [AsPh₄][Cl₁₁], [PPh₄][Cl₁₁], and [PNP][Cl₁₁]?Cl₂, and [Cl₁₃]^? obtained in [PNP][Cl₁₃]. The polychloride dianion [Cl₁₂]^2? has been obtained in [NMe₃Ph]₂[Cl₁₂]. The novel compounds have been thoroughly characterized by NMR spectroscopy, single‐crystal Raman spectroscopy, and single‐crystal X‐ray diffraction. The assignment of their spectra is supported by molecular and periodic solid‐state quantum‐chemical calculations.     

Dinuclear Manganese(II) Complexes with Bridging Selenidodiarsenate Anions [As2Se4]4−, [As2Se5]4− and [As2Se6]2−

Solvothermal reaction of [MnCl₂(amine)] (amine = terpy and tren) with elemental As and Se at a 1:1:2 molar ratio in H₂O/tren (10:1) affords the dimanganese(II) complexes [{Mn(terpy)}₂(μ‐As₂Se₄)] ( 1 ) and [{Mn(tren)}₂(μ‐As₂Se₅)] ( 2 ) respectively. The tetradentate [As₂Se₄]^4? bridging ligands in 1 contain a central As–As bond and exhibit approximately C_2h symmetry. Pairs of gauche sited Se atoms participate in five‐membered As₂Se₂Mn chelate rings. In contrast, two AsSe₃ pyramids share a common corner in the [As₂Se₅]^4? ligands of 2 and each coordinates an [Mn(tren)]²⁺ fragment through a single terminal Se atom. Such dinuclear complexes are linked into tetranuclear moieties through weak Se···Mn interactions of length 3.026(3) Å involving one of these terminal Se atoms. At a 1:3:6 molar ratio, solvothermal reaction of [MnCl₂(tren)] with As and Se leads to formation of a second dinuclear complex [{Mn(tren)}₂(μ‐As₂Se₆)₂] ( 3 ), which contains two bridging bidentate [As₂Se₆]^2? ligands. These are cyclic with an As₂Se₄ ring and can be regarded as being derived from [As₂Se₅]^4? anions by formation of two Se‐Se bonds to an additional Se atom.     

Sind die ‚Lehrbuch-Anionen’︁ O2−, [CO3]2− und [SO4]2− Fiktionen?

Are the ‘Textbook Anions’ O^2?, [CO₃]^2?, and [SO₄]^2? Fictitious? Experimental second electron affinities are still unknown for the title anions. It will be shown by means of quantum chemical ab initio calculations that these dianions are unstable with respect to spontaneous ionization. They all must be designated as non-existent.     

Coordination of Alkaline Earth Metal Ions in the Inverted Cucurbit[7]uril Supramolecular Assemblies Formed in the Presence of [ZnCl4]2− and [CdCl4]2−

A convenient method to isolate inverted cucurbit[7]uril (iQ[7]) from a mixture of water‐soluble Q[n]s was established by eluting the soluble mixture of Q[n]s on a Dowex (H⁺ form) column so that iQ[7] could be selected as a ligand for coordination and supramolecular assembly with alkaline earth cations (AE²⁺) in aqueous HCl solutions in the presence of [ZnCl₄]^2? and [CdCl₄]^2? anions as structure‐directing agents. Single‐crystal X‐ray diffraction analysis revealed that both iQ[7]–AE²⁺–[ZnCl₄]^2?–HCl and iQ[7]–AE²⁺–[CdCl₄]^2?–HCl interaction systems yielded supramolecular assemblies, in which the [ZnCl₄]^2? and [CdCl₄]^2? anions presented a honeycomb effect, and this resulted in the formation of linear iQ[7]/AE²⁺ coordination polymers through outer‐surface interactions of Q[n]s.