Bromine-rich Zinc Bromides: Zn₆Br₁₂(18-crown-6)₂×(Br₂)₅, Zn₄Br₈(18-crown-6)₂×(Br₂)₃, and Zn₆Br₁₂(18-crown-6)₂×(Br₂)₂

Abstract

The bromine-rich zinc bromides Zn6Br12(18-crown-6)2×(Br2)5 (1), Zn4Br8(18-crown-6)2×(Br2)3 (2), and Zn6Br12(18-crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-crown-6), Zn2Br4(18-crown-6)) or ionic (e.g., [Zn2Br3(18-crown-6)](+), [(Zn2Br6)×(Br2)2](2-)) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape.

A Novel Family of Polyiodo‐Bromoantimonate(III) Complexes: Cation‐Driven Self‐Assembly of Photoconductive Metal‐Polyhalide Frameworks

“…However, despite the general progress in this field, it can be noted that the polyhalide metal complexes remain incomparably less explored. For the all‐polyhalide complexes, single examples are known for polyiodides and polybromides . Coordination of mixed polyhalides ((BrI 2 ) − , (ClBr 2 ) − ) was reported mostly for heteroligand complexes …”

“…For the all-polyhalidec omplexes, single examplesa re known for polyiodides [8][9][10][11] and polybromides. [12][13][14][15][16][17] Coordination of mixed polyhalides( (BrI 2 ) À , (ClBr 2 ) À )w as reported mostly for heteroligand complexes. [18][19][20][21] Very recently, we discovered as eries of Bi III polybromide complexes,f eaturing ar emarkable structurald iversity and con-taining{ Br x }u nits of variable nuclearity (upt o9 ).…”

[NMe4][I4Br5]: A new Iodobromide from an Ionic Liquid with Halogen–Halogen Interactions

“…As econd explanationc ould be hydrogen bonds which favor band structures of syn-[I 4 Br 5 ] À .B ut with 297.2 and 299.9 pm the bonding between the terminal bromine atom and the [NMe 4 ] + cation is very weak compared to typical literature values (240-280pm). [21] In [NMe 4 ] 2 [I 4 Br 5 ] 2 we only obtained hydrogen bonding for one of the two [I 4 Br 5 ] À anions with 250.1 and2 92.3 pm. Therefore it is not substantially responsible for the structural motif although one of the bondingi s as trongero ne.…”

Polymeric Lead(II) Iodoacetate: Pb···I and I···I Non‐Covalent Interactions in the Solid State

“…Apart from fundamental interest, this special type of non‐covalent interactions provides attractive tools for design of functional materials and sensor systems . Currently, there exist several classes of organic “building blocks” which are especially widely applied when aiming formation of XB, in particular, iodoarenes, halogenated alkanes, polyhalides,, halogenated pyridines, etc. Halogenated carboxylic acids (both aromatic and aliphatic) are rarely utilized as XB building blocks, in particular with heavier halides where the formation of halogen bonds can be expected.…”