Berg Rolf W, Harris Pernille, Riisager Anders, Fehrmann Rasmus
Department of Chemistry and §Centre for Catalysis and Sustainable Chemistry, Technical University of Denmark , Building 207, DK-2800 Kongens Lyngby, Denmark.
J Phys Chem A. 2013 Nov 7;117(44):11364-73. doi: 10.1021/jp408069n. Epub 2013 Oct 25.
A unique new ionic liquid-gas adduct solid state compound formed between 1,1,3,3-tetramethylguanidinium chloride ([tmgH]Cl) and sulfur dioxide has been characterized by X-ray diffraction and Raman spectroscopy. The structure contains SO2 molecules of near normal structure kept at their positions by Cl-S interactions. The crystals belong in the orthorhombic system, space group Pbcn, with unit cell dimensions of a = 15.6908(10) Å, b = 9.3865(6) Å, and c = 14.1494(9) Å, angles α = β = γ = 90°, and Z = 8 at 120 K. The [tmgH]Cl has a very high absorption capacity of nearly 3 mol of SO2 per mol of [tmgH]Cl at 1 bar of SO2 and at room temperature. However, part of the absorbed SO2 was liberated during the crystallization, probably because the crystal only accommodates one molecule of SO2 per [tmgH]Cl. The nature of the high absorption capacity of [tmgH]Cl as well as of the homologous compounds with bromide and iodide are discussed. Some of these salts may prove useful as reversible absorbents of SO2 in industrial flue gases.
一种由氯化1,1,3,3 - 四甲基胍（[tmgH]Cl）与二氧化硫形成的独特新型离子液体 - 气体加合物固态化合物已通过X射线衍射和拉曼光谱进行了表征。该结构包含结构接近正常的SO₂分子，它们通过Cl - S相互作用保持在各自的位置。晶体属于正交晶系，空间群为Pbcn，在120 K时，晶胞参数为a = 15.6908(10) Å，b = 9.3865(6) Å，c = 14.1494(9) Å，α = β = γ = 90°，Z = 8。在1 bar的SO₂压力和室温下，[tmgH]Cl具有非常高的吸收容量，每摩尔[tmgH]Cl近乎能吸收3摩尔的SO₂。然而，部分被吸收的SO₂在结晶过程中释放出来，可能是因为每个[tmgH]Cl晶体仅容纳一个SO₂分子。讨论了[tmgH]Cl以及含溴化物和碘化物的同源化合物的高吸收容量的性质。其中一些盐可能被证明可作为工业烟道气中SO₂的可逆吸收剂。
