Preparation and X-ray structure of [H3O+�18-crown-6]-[(H5O 2 + )(Cl?)2], a compound containing both H3O+ and H5O 2 + crystallized from aromatic solution

Hybrid Disila-Crown Ethers as Hosts for Ammonium Cations: The O–Si–Si–O Linkage as an Acceptor for Hydrogen Bonding

Host-guest chemistry was performed with disilane-bearing crown ethers and the ammonium cation. Equimolar reactions of 1,2-disila[18]crown-6 (1) or 1,2-disila-benzo[18]crown-6 (2) and NH4PF6 in dichloromethane yielded the respective compounds [NH4(1,2-disila[18]crown-6)]PF6 (3) and [NH4(1,2-disila-benzo[18]crown-6)]PF6 (4). According to X-ray crystallographic, NMR, and IR experiments, the uncommon hydrogen bonding motif O(Si)∙∙∙H could be observed and the use of cooperative effects of ethylene and disilane bridges as an effective way to incorporate guest molecules was illustrated.

Hydrogen bonded anion ribbons, networks and clusters and sulfur-anion interactions in novel radical cation salts of BEDT-TTF with sulfamate, pentaborate and bromide

The novel radical cation salt (BEDT-TTF)3(sulfamate)2·2H2O (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) is semiconducting with donor stacks comprised of pairs of partially oxidized molecules and a single more highly oxidized molecule which is twisted out of the stack by ca. 30°. Hydrogen bonded pairs of sulfamate ions are linked into parallel ribbons by further hydrogen bonding between sulfamates and bridging water molecules. In contrast, the BEDT-TTF salt with pentaborate contains infinite layers formed of a network of hydrogen bonded pentaborate anions. Two new bromide salts of BEDT-TTF are reported, one is a semiconducting 1 : 1 salt in which the bromide is integrated among the BEDT-TTF donors, while the other contain a square of four bromide ions linked together by hydrogen bonding to a centrally located H5O2(+) cation for every five BEDT-TTF molecules.

Luminescence and structural comparisons of strong-acid sensor molecules. 2

Anthraquinone-containing cyclic polyether hosts form 1:1 complexes with hydronium ion, producing large enhancements in luminescence via inversion of npi* and pipi* exited states. We have characterized the binding of hydronium ion within these host molecules and have synthesized a large variety of analogous hosts that contain different structural and electronic features that allow better understanding of what controls binding and luminescence capacity in this class of fluorescent sensor molecules. X-ray crystallography of an anthraquinone host that contains terminal amine functional groups rather than terminal ether groups is investigated, and complete proton transfer to carbonyl groups is observed in concentrated sulfuric acid media that also produces a previously unobserved luminescence.

Oxonium ions from aqua regia: isolation by hydrogen bonding to crown ethers

The preparation and structures of a variety of oxonium ion tetrachloroaurate(III) salts isolated from aqua regia are reported. The new compounds are [(H(5)O(2))(2)(12-crown-4)(2)][AuCl(4)](2) (1), [(H(7)O(3))(15-crown-5)][AuCl(4)] (2), [(H(5)O(2))(benzo-15-crown-5)(2)][AuCl(4)] (3), [(H(3)O)(18-crown-6)][AuCl(4)] (4), [(H(5)O(2))(dibenzo-24-crown-8)][AuCl(4)] (5), [(H(5)O(2))(4-nitrobenzo-15-crown-5)(2)][AuCl(4)] (6), [(H(3)O)(4-nitrobenzo-18-crown-6)][AuCl(4)] (7), [(H(11)O(5))(tetrachlorodibenzo-18-crown-6)(2)][AuCl(4)] (8), and [(H(7)O(3))(dinitrodibenzo-30-crown-10)][AuCl(4)] (9). A significant correlation between the degree of proton hydration and crown ether size is observed. Aryl crown ethers are nitrated in concentrated aqua regia, but nonnitrated products may be obtained in a dilute solution of aqua regia by reaction with aqueous HAuCl(4).

Formation of Lanthanide and Actinide Oxonium Ion Complexes with Crown Ethers from a Liquid Clathrate Medium

Reaction of MCl(3).nH(2)O (M = La, Eu) with 18-crown-6 in HCl/toluene affords the crystalline oxonium complexes (H(9)O(4))[LaCl(2)(H(2)O)(18-crown-6)]Cl(2) (1) and (H(3)O)[EuCl(H(2)O)(2)(18-crown-6)]Cl(2) (2). In complex 1 the H(9)O(4)(+) cation is of the unusual linear chain type with O.O contacts of 2.560(9), 2.430(9), and 2.483(9) Å. The analogous reaction with YbCl(3).6H(2)O results in the isolation of the known species (H(5)O(2))[H(3)O.(18-crown-6)]Cl(2). Analogous reaction of YbCl(3).6H(2)O with 15-crown-5 gives [Yb(H(2)O)(8)]Cl(3).(15-crown-5) (5). Reaction of uranyl acetate with 15-crown-5 within a toluene/HCl mixture results in the formation of a yellow liquid clathrate layer from which crystals of (H(5)O(2))[UO(2)(H(2)O)(2)Cl(3)].2(15-crown-5) (6) are deposited. The H(5)O(2)(+) ion in this material exhibits a particularly short O.O separation of 2.371(8) Å. On standing, loss of HCl results in the transformation of 6 into a species of empirical formula [UO(2)(H(2)O)(3)Cl(2)].(15-crown-5) (7) which has been shown by X-ray crystallography to contain 16 unique uranium complexes, arranged in infinite hydrogen-bonded chains in the solid state. Crystal data for 1: monoclinic, P2(1)/c, a = 7.6950(2) Å, b = 21.2160(16) Å, c = 15.8650(10) Å, beta = 92.866(2) degrees, V = 2586.8(3) Å(3), Z = 4. 2: orthorhombic, Pbn2(1), a = 10.2267(6) Å, b = 14.7231(9) Å, c = 29.8565(18) Å, V = 4495.5(5) Å(3), Z = 4. 5: monoclinic, P2(1)/n, a = 9.1740(3) Å, b = 17.1900(3) Å, c = 15.2450(5) Å, beta = 92.643(2) degrees, V = 2401.60(12) Å(3), Z = 4. 6: orthorhombic, Pmcn, a = 12.1740(5) Å, b = 14.7740(7) Å, c = 18.4920(11) Å, V = 3325.9(3) Å(3), Z = 4. 7: trigonal, P3(2), a = 35.3500(2) Å, c = 21.3755(2) Å, V = 23 132.7(3) Å(3), Z = 48.

Synthesis, Reactivity, and Structure of [H(13)O(6)][PtCl(5)(H(4)O(2))].2(18-cr-6): A Crown Ether Complex of a Pentachloroaquaplatinic Acid with an [H(13)O(6)](+) Cation in a Cage of Three Crown Ether Molecules

An aqueous solution of H(2)[PtCl(6)].6 H(2)O reacts with crown ether 18-crown-6 to give [H(13)O(6)][PtCl(5)(H(4)O(2))]. 2(18-cr-6)(1) (1) and (H(3)O)(2)[PtCl(6)].2(18-cr-6) (2a). In the presence of HCl, only 2a is formed; in an analogous manner, (H(3)O)(2)[PtCl(6)].2(15-cr-5).2 H(2)O (2b) and (H(3)O)(2)[PtCl(6)].2(DCH-18-cr-6)(1) (2c) were obtained. 1 is gradually decomposed in water to give [PtCl(4)(H(2)O)(2)].(18-cr-6).2H(2)O (3). 1-3 were characterized by microanalysis and IR and NMR spectroscopy ((1)H, (13)C, (195)Pt). The X-ray structure analysis of 1 (orange needles; space group P2(1)2(1)2(1), a = 7.938(1) Å, b = 15.691(2) Å, c = 34.861(4) Å; Z = 4) shows an anionic entity [PtCl(5)(H(4)O(2))](-) and a cationic entity [H(13)O(6)](+) which are separated by a crown ether molecule 18-cr-6. The [H(13)O(6)](+) cations exhibit the structure [H(3)O(H(4)O(2))(2)(H(2)O)](+) and are also separated by crown ether molecules in such a way that the crystal is threaded by chains built up of 18-cr-6/[H(13)O(6)](+) units at which the 18-cr-6/[PtCl(5)(H(4)O(2))](-) moieties are fixed as lateral branches. Thus, the cations [H(13)O(6)](+) are embedded in three crown ether molecules. All terminal hydrogens are involved in hydrogen bridges to oxygen atoms of the crown ether molecules. The O(w).O(cr) distances are distinctly longer in the mean than the O(w).O(w) distances within the [H(13)O(6)](+) moiety.