Synthesis of salts of the hydrogen dichloride anion in aromatic solvents. 2. Syntheses and crystal structures of [K.cntdot.18-crown-6][Cl-H-Cl], [Mg.cntdot.18-crown-6][Cl-H-Cl]2, [H3O.cntdot.18-crown-6][Cl-H-Cl], and the related [H3O.cntdot.18-crown-6][Br-H-Br]

Abstract

the structure was straightforward from application of the heavy-atom method. Space group Pbca was confirmed and the position of the iron atom was deduced from the three-dimensional Patterson function. The positions of the remaining non-hydrogen atoms were determined through subsequent Fourier and difference Fourier calculations.Least-squares refinementz9 of the 35 non-hydrogen atoms, varying the iron atom anisotropically, produced unweighted and weighted residuals of 8.7% and 7.1%,'O respectively. Hydrogen atom positions were calcu-lated by using a C-H distance of 0.95 8, and an isotropic thermal parameter of 6.0 Az. Further refinement resulted in residuals of R = 7.2% and R, = 5.5%. The final difference Fourier map had no peak greater than 0.26 e/8,'.Acknowledgment is made to the National Institutes of Health (GM 28938) and the Department of Energy, Office of Basic Energy Sciences (85ER 13430), for support of this work. Tables of complete anisotropic and isotropic temperature factors, bond distances and angles, calculated hydrogen positions, and defined planes and calculated dihedral angles for 2 (3 pages); a table of calculated and observed structure factors for 2 (IO pages). Ordering information is given on any current masthead page. The reaction of HCI(g), H 2 0 , and 18-crown-6 in toluene gives [H30.18-crown-6] [CI-H-C1]-3.6tol (to1 = toluene), from which crystals of [H30.18-crown-6] [CI-H-CIJ are isolated: space group P2,/c; a = 10.475 (7), b = 20.767 (9), c = 8.583 (7) 8,; @ = 96.23 (3)'; Z = 4 for D, = 1.28 g cW3; R = 0.042 for 493 independent observed reflections. The liquid clathrate [H30.18crown-61 [CI-H-CI].3.6tol dissolves KCI, and upon standin , the solution affords crystals of [K.18-crown-6] [CI-H-CI]: space group P2,/c; a = 8.325 (2), b = 14.094 (4), c = 7.893 (6) ! ; @ = 98.56 (4)'; 2 = 2 for 0, = 1.37 g cm-'; R = 0.055 for 1194 independent observed reflections. In a similar fashion, the liquid clathrate dissolves MgCI, and yields [Mg18-crown-6] [C1-H-Cll2: space group Pbca; a = 18.310 (7), b = 7.512 (6), c = 29.085 ( 8 ) A; Z = 8 for D, = 1.44 g cm-'; R = 0.066 for 1204 observed reflections. The [Br-H-BrI-anion is produced by the reaction of HBr(g), HzO, and 18-crown-6 in toluene. [H30.18-crown-6][Br-H-Br] is isomorphous with the [CI-H-CI]-analogue, and the crystals belong to space group P2,/c with a = 10.588 ( I ) A, b = 21.060 (2) A, c = 8.753 ( I ) A, @ = 95.25 (4)O, and D, = 1.52 g cm-' for Z = 4; R = 0.059 for 1697 observed reflections. Supplementary Material Available:The CI-.CI separations range from 3.11 ( I ) 8, in the H30+ salt to 3.331 (2) 8, in the Mg2+ analogue. The angle at the hydrogen atom in the hydrogen dichloride ranges from 161' for the [Mg18-cro~n-6]~+salt to 180° for the [K.18-crown-6]+salt. The short CI-CI separations in the H30+ and K+ salts are attributed to the absence of a strong directional interaction of the anion with the cation. For the long CI-.CI in the Mgz+ case, the magnesium atom is bonded to one of the chlorine atoms at 2.428 (6) and 2.454 (3) A (two indepen...

Mysterious Decomposition of Alkoxyphosphonium Chlorides: Postulated Involvement of the HCl2 Anion and Its Capture in the Solid State

“…However, as positions of electron‐stripped hydrogen atoms cannot be reliably obtained from the diffraction data the exact values of d HCl could not be determined with high degree of certainty. Similar geometry of this anion has been reported in its salts with magnesium‐crown ether cationic complexes …”

“…Similar geometry of this anion has been reported in its salts with magnesium-crown ether cationic complexes. [23] The crystalline R P -1b·HCl 2 can be stored at À20 8Cv irtually indefinitely.T he NMR characterisation of this salt carriedo ut at 0 8Ci nC DCl 3 (see the Supporting Information for details) revealed, within the detection limit of this measurement, the presenceo fo nly one diastereomer (d P = 67 ppm). Considering that the 13 C 1 J C-P satellite signals are clearly visible, and the peak of the minor diastereomer is not,t he de of the sample is at least but clearly highert han 99 %.…”

Synthesis and Characterization of Poly(hydrogen halide) Halogenates (–I)

“…Hydrogen bromide is aw eaker hydrogen bond donor compared to HCl and HF and only two examples of halide HBr adducts are known in the literature ([BrHBr] À [10] and [Br(HBr) 2 ] À [11] ). The reaction of bromide salts with over-stoichiometric amountso fH Br leads to the formation of rather instable compounds which could not be characterizedw hile the reactiono f Recently it was shown that BrCN forms adducts with bromide to form [Br(BrCN) n ] À anions (n = 1, 3) by halogen bonding interactions.…”

“…Crystal structures of [Cat][F(HF) n ]( [Cat] = [NO] + (n = 3, 4), [8] [NMe 3 H] + (n = 2-6), [6] [NMe 4 ] + (n = 2, 3, 5) [3] )a sw ell as [Cat][Cl(HCl) n ]( Cat = [SMe 2 H] + (n = 3, 4), [7] [C 5 H 5 NH] + (n = 1, 4, 5) [5] )w ere determined by X-ray diffraction (XRD) using am iniature zone-melting technique for crystallization.S tructures containing ap rotonated base as a cation, like [NMe 3 H] + ,s how strong hydrogen bonding betweena nion and cation, whereas less coordinating cations, for example, [NMe 4 ] + ,y ield more isolated anions. For the heavier homologues only [BrHBr] À [10] and [Br(HBr) 2 ] À [11] have been characterized by X-ray diffraction while no molecular structure in the solid state is knownf or [I(HI) n ] À anions. The behavior of [X(HX) n ] À anionsi ns olution was investigated using NMR spectroscopyb ys everal groups.…”

Iridium(III) catalyzed oxidation of iodide ions in aqueous acidic medium

“…Existance of HX 2 ) ion (where X is a halogen atom) at least in the gas phase, inert gas mixtures and aprotic solvents [37][38][39] has been reported. However, even this possibility will not affect our results and the final rate law.…”