The new cation [Sb7S8Br2]3+ has a double-cubane structure and forms as the [AlCl4]− salt from the ionic liquid EMIMBr−AlCl3 (EMIM = 1-ethyl-3-methylimidazolium) at 165 °C. The compound is noncentrosymmetric with space group P212121 and exhibits second-harmonic and difference-frequency nonlinear optical response across a wide range of the visible and near-infrared regions.

Chalcogenide chemistry in ionic liquids: nonlinear optical wave-mixing properties of the double-cubane compound [Sb7S8Br2](AlCl4)3.

Pancake bonds: π-Stacked dimers of organic and light-atom radicals

Recent advances in the understanding of the syntheses, structures, bonding and energetics of the homopolyatomic cations of Groups 16 and 17

The Lewis acidic ionic liquid EMIMBr-AlCl3 (EMIM = 1-ethyl-3-methylimidazolium) allows a novel synthetic route to the semiconducting layered metal chalcogenides halide [Bi2Te2Br](AlCl4) and its Sb analogue. [Bi2Te2Br](AlCl4) is a direct band gap, strongly anisotropic semiconductor and consists of cationic infinite layers of [Bi2Te2Br]+ and [AlCl4]− anions inserted between the layers.

Synthesis in Ionic Liquids: [Bi2Te2Br](AlCl4), a Direct Gap Semiconductor with a Cationic Framework

IV. Se−Se, Te−Te, and Mixed Dications 248 V. Trischalcogen Dications 251 VI. Polyatomic Chalcogen Dications 254 A. Preparation 255 B. Chemical Properties 256 VII. N−N Dications 257 A. Hydrazinium Dications 257 1. Synthesis of Hydrazinium Dications 257 2. Properties of Hydrazinium Dications 259 3. Heteroaromatic N,N-Dications 262 B. Diazenium and Diazonium Dications 262 1. Synthesis of Diazenium Dications 262 2. Reactions of Diazenium Dications 263 3. Diazonium Dications 265 4. Mixed Dications 266 VIII. P−P Dications 266 A. Synthesis of Diphosphonium Dications 266 B. Reactions of Diphosphonium Dications: Nucleophilic Substitution 267

T. Klapoetke

Papers

Sulfur and selenium iodine compounds: from non-existence to significance