3，5-二羟基-2，4，6-三硝基苯酚铷的晶体结构和热行为

0IntroductionSom e nitrogen鄄rich alkaline and alkali鄄earth m et鄄als com pounds of polynitro hydroxybenzenes can beused environm entally friendly prim ary explosives[1￣5].2,4,6鄄Trinitro鄄1,3,5鄄trihydroxybenzene(trinitrophloroglu鄄cinol,TNPG)belongs to a polynitro hydroxybenzeneand has been used in chem icalindustry as an ingredi鄄entfor prim ing com position,percussion caps and deto鄄nator form ulations[6].Therefore,in recent years,ithasbeen exploited to prepare a num ber of salts of ba…     

The structures of the isomorphous potassium and rubidium salts of 4‐nitrobenzoic acid and an overview of the metal complex stereochemistries of the alkali metal salt series with this ligand

4‐Nitrobenzoic acid (PNBA) has proved to be a useful ligand for the preparation of metal complexes but the known structures of the alkali metal salts of PNBA do not include the rubidium salt. The structures of the isomorphous potassium and rubidium polymeric coordination complexes with PNBA, namely poly[μ₂‐aqua‐aqua‐μ₃‐(4‐nitrobenzoato)‐potassium], [K(C₇H₄N₂O₂)(H₂O)₂]_n, (I), and poly[μ₃‐aqua‐aqua‐μ₅‐(4‐nitrobenzoato)‐rubidium], [Rb(C₇H₄N₂O₂)(H₂O)₂]_n, (II), have been determined. In (I), the very distorted KO₆ coordination sphere about the K⁺ centres in the repeat unit comprise two bridging nitro O‐atom donors, a single bridging carboxylate O‐atom donor and two water molecules, one of which is bridging. In Rb complex (II), the same basic MO₆ coordination is found in the repeat unit, but it is expanded to RbO₉ through a slight increase in the accepted Rb—O bond‐length range and includes an additional Rb—O_carboxylate bond, completing a bidentate O,O′‐chelate interaction, and additional bridging Rb—O_nitro and Rb—O_water bonds. The comparative K—O and Rb—O bond‐length ranges are 2.7352 (14)–3.0051 (14) and 2.884 (2)–3.182 (2) Å, respectively. The structure of (II) is also isomorphous, as well as isostructural, with the known structure of the nine‐coordinate caesium 4‐nitrobenzoate analogue, (III), in which the Cs—O bond‐length range is 3.047 (4)–3.338 (4) Å. In all three complexes, common basic polymeric extensions are found, including two different centrosymmetric bridging interactions through both water and nitro groups, as well as extensions along c through the para‐related carboxylate group, giving a two‐dimensional structure in (I). In (II) and (III), three‐dimensional structures are generated through additional bridges involving the nitro and water O atoms. In all three structures, the two water molecules are involved in similar intra‐polymer O—H...O hydrogen‐bonding interactions to both carboxylate and water O‐atom acceptors. A comparison of the varied coordination behaviour of the full set of Li–Cs salts with 4‐nitrobenzoic acid is also made.     

Gas‐phase fragmentation reactions of protonated benzofuran‐ and dihydrobenzofuran‐type neolignans investigated by accurate‐mass electrospray ionization tandem mass spectrometry

We have investigated gas‐phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate‐mass electrospray ionization tandem and multiple‐stage (MSⁿ) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ([M + H–MeOH]⁺), C ([ B –MeOH]⁺), D ([ C –CO]⁺), and E ([ D –CO]⁺) upon collision‐induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features. In the case of compounds displaying an acetoxy group at C‐4, product ion C produces diagnostic ions K ([ C –C₂H₂O]⁺), L ([ K –CO]⁺), and P ([ L –CO]⁺). Formation of product ions H ([ D –H₂O]⁺) and M ([ H –CO]⁺) is associated with the hydroxyl group at C‐3 and C‐3′, whereas product ions N ([ D –MeOH]⁺) and O ([ N –MeOH]⁺) indicate a methoxyl group at the same positions. Finally, product ions F ([ A –C₂H₂O]⁺), Q ([ A –C₃H₆O₂]⁺), I ([ A –C₆H₆O]⁺), and J ([ I –MeOH]⁺) for DBNs and product ion G ([ B –C₂H₂O]⁺) for BNs diagnose a saturated bond between C‐7′ and C‐8′. We used these structure‐fragmentation relationships in combination with deuterium exchange experiments, MSⁿ data, and Computational Chemistry to elucidate the gas‐phase fragmentation pathways of these compounds. These results could help to elucidate DBN and BN metabolites in in vivo and in vitro studies on the basis of electrospray ionization ESI‐CID‐MS/MS data only.     

Alkali metal halogenides coordination compounds with hexamethylenetetramine

Six coordination compounds: [Li(H₂O)₄]⁺·hmta·Cl^?, [Li(H₂O)₄]⁺·hmta·I^?, [Na(H₂O)₄(hmta)] ²⁺₂ ·2H₂O·2Br^?, [Na(H₂O)₄(hmta)] ²⁺₂ ·2H₂O·2I^?, [K(H₂O)(hmta)I] _n and [Rb(H₂O)(hmta)I] _n , have been synthesized and characterised by IR spectroscopy, thermogravimetry coupled with differential thermal analysis, elemental analysis and X-ray crystallography. Both the sodium compounds are isostructural in a solid state, an isostructurality is also observed between compounds containing potassium and rubidium iodides. The sodium compounds exist as dimers (dinuclear core of the complex ion is created by two sodium cations and two water molecules). The molecules of potassium and rubidium compounds are assembled to the two dimensional hybrid nets. The each potentially multifunctional ligand (the hmta) exists in the outer coordination sphere in lithium compounds, acts in a monodentate mode in sodium compounds and in bidentate-bridging modes in potassium and rubidium compounds. The lithium ions are four coordinated, and the sodium, potassium and rubidium ions are six coordinated. Thermal analyses show that the investigated compounds decompose gradually with the formation of alkali metal halides which, during the further heating, are totally removed or they undergo partial decomposition to oxides.

     

Possibilities of applying the Piloyan method of determination of decomposition activation energies

Activation energies (E) of the thermal decomposition and the initial valuesT _D of the exotherms are determined for trinitroaniline, trinitro-m-phenylenediamine, trinitrotriaminobenzene, trinitrophenol, trinitroresorcinol, trinitro-m-cresol and hexanitrooxanilide. Linear relationships are derived between the termsE.T _D ^1? and published kinetics data on these compounds, obtained by an isothermal manometric method. The mechanisms of the primary steps in the thermolyses of these polynitro compounds are discussed. A positive influence on their thermal stability has been confirmed, arising from the contact of the measured compounds with the glass surface.     

Heavy Alkali Metal Manganate Complexes: Synthesis,Structures and Solvent-Induced Dissociation Effects

Rare examples of heavier alkali metal manganates [{(AM)Mn(CH₂SiMe₃)(N^‘Ar)₂}_∞] (AM=K, Rb, or Cs) [N^‘Ar=N(SiMe₃)(Dipp), where Dipp=2,6-iPr₂-C₆H₃] have been synthesised with the Rb and Cs examples crystallographically characterised. These heaviest manganates crystallise as polymeric zig-zag chains propagated by AM⋅⋅⋅π-arene interactions. Key to their preparation is to avoid Lewis base donor solvents. In contrast, using multidentate nitrogen donors encourages ligand scrambling leading to redistribution of these bimetallic manganate compounds into their corresponding homometallic species as witnessed for the complete Li - Cs series. Adding to the few known crystallographically characterised unsolvated and solvated rubidium and caesium s-block metal amides, six new derivatives ([{AM(N^‘Ar)}_∞], [{AM(N^‘Ar)⋅TMEDA}_∞], and [{AM(N^‘Ar)⋅PMDETA}_∞] where AM=Rb or Cs) have been structurally authenticated. Utilising monodentate diethyl ether as a donor, it was also possible to isolate and crystallographically characterise sodium manganate [(Et₂O)₂Na(ⁿBu)Mn[(N^‘Ar)₂], a monomeric, dinuclear structure prevented from aggregating by two blocking ether ligands bound to sodium.     

Hydroxidmonohydrate des Kaliums und Rubidiums; Verbindungen,deren Atomanordnungen die Schreibweise K(H2O)OH bzw. Rb(H2O)OH nahelegen

Hydroxide Monohydrates of Potassium and Rubidium; Compounds with Atomic Arrangements which Suggest the Formula K(H₂O)OH and Rb(H₂O)OH Single crystals for x-ray structure investigations of the monohydrates of potassium and rubidium hydroxides were obtained by recrystallization of microcrystalline sampels in supercritical ammonia as solvent. The structure determination on both structurally closely related compounds was successful up to the localization of the hydrogen positions. Besides the monohydrates were characterized by IR spectra and thermochemical data. The atomic arrangement of the compounds is discussed in comparison to the one of substances as PbFCl, γ-AlOOH etc. In addition to the chemical bonds in the stated compounds both monohydrates show one-dimensional infinite hydrogen bridges between the H atoms of the water molecules and the hydroxide ions; furthermore weak H bonds connect the OH^? ions. Because the hydroxide ions are involved in two bridge-bindung systems water molecules are the nearest neigh-bours of the cations.     

Synthetic, structural, and theoretical investigations of alkali metal germanium hydrides--contact molecules and separated ions

The preparation of a series of crown ether ligated alkali metal (M=K, Rb, Cs) germyl derivatives M(crown ether)_nGeH₃ through the hydrolysis of the respective tris(trimethylsilyl)germanides is reported. Depending on the alkali metal and the crown ether diameter, the hydrides display either contact molecules or separated ions in the solid state, providing a unique structural insight into the geometry of the obscure GeH₃^? ion. Germyl derivatives displaying M? Ge bonds in the solid state are of the general formula [M([18]crown‐6)(thf)GeH₃] with M=K ( 1 ) and M=Rb ( 4 ). The compounds display an unexpected geometry with two of the GeH₃ hydrogen atoms closely approaching the metal center, resulting in a partially inverted structure. Interestingly, the lone pair at germanium is not pointed towards the alkali metal, rather two of the three hydrides are approaching the alkali metal center to display M? H interactions. Separated ions display alkali metal cations bound to two crown ethers in a sandwich‐type arrangement and non‐coordinated GeH₃^? ions to afford complexes of the type [M(crown ether)₂][GeH₃] with M=K, crown ether=[15]crown‐5 ( 2 ); M=K, crown ether=[12]crown‐4 ( 3 ); and M=Cs, crown ether=[18]crown‐6 ( 5 ). The highly reactive germyl derivatives were characterized by using X‐ray crystallography, ¹H and ¹³C NMR, and IR spectroscopy. Density functional theory (DFT) and second‐order Møller–Plesset perturbation theory (MP2) calculations were performed to analyze the geometry of the GeH₃^? ion in the contact molecules 1 and 4 .     

Theoretical Study of Structural Relationships and Electrochemical Properties of Supramolecular [14-MR Macrolides]@Cn Complexes

Macrolides are a broad spectrum of antibiotics that are commonly used in human pathologies as well as in veterinary medicine. The electrochemical detection of macrolide antibiotics were studied at various methods using amperometric and coulometric detectors. Since the discovery of fullerenes (C_n), one of the main classes of carbon compounds, the unusual structures and physiochemical properties of these molecules have been discovered, and many potential applications and physicochemical properties have been introduced. Up to now, various empty carbon fullerenes with different numbers “n,” such as C₆₀, C₇₀, C₇₆, C₈₂, and C₈₆, have been obtained. Topological indices are digital values that are assigned based on chemical composition. These values are purported to correlate chemical structures with various chemical and physical properties. They have been successfully used to construct effective and useful mathematical methods to establish clear relationships between structural data and the physical properties of these materials. In this study, the number of carbon atoms in the fullerenes was used as an index to establish a relationship between the structures of Erythromycin-A (EA), Erythromycin-A enol ether (EMEN), Olendomycin (OM), and Anhydroerythromycin-A (AEA), 1-4 and fullerenes C_n (n = 60, 70, 76, 82 and 86), which create [Tetracyclines]@C_n, A-1 to A-5 ([EA]@C_n), B-1 to B-5 ([EMEN]@C_n), C-1 to C-5 ([OM]@C_n), and D-1 to D-5 ([AEA]@C_n). The relationship between the number of carbon atoms and the free energies of electron transfer (ΔG_et(1) to ΔG_et(4)) is assessed using the Rehm-Weller equation for A-1 to A-5, B1 to B-5, C-1 to C-5, and D-1 to D-5 supramolecular [14-MR Macrolides]@C_n complexes 5-24. Calculations are presented for the four reduction potentials (^Red.E₁ to ^Red.E₄) of fullerenes C _n . The results were used to calculate the four free-energies of electron transfer (ΔG_et(1) to ΔG_et(4)) of supramolecular complexes A-1 to A-18 to B-1 to B-18, C-1 to C-18, and D-1 to D-18 (5-76) for fullerenes C₆₀ to C₃₀₀.     

Theoretical study of interactions between 1-alkyl-3-methyimidazolium tetrafluoroborate and dibenzothiophene: DFT,NBO, and AIM analysis

Density functional theory is employed to study the interaction energies between dibenzothiophene (DBT) and 1-alkyl-3-methylimidazolium tetrafluoroborate ([C _n mim]⁺[BF₄]^?). The structures of DBT, 1-ethyl-3-methylimidazolium tetrafluoroborate ([C₂mim]⁺[BF₄]^?), 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]+[BF₄]?), 1-hexyl-3-methylimidazolium tetrafluoroborate ([C₆mim]⁺[BF₄]^?), 1-octyl-3-methylimidazolium tetrafluoroborate ([C₈mim]⁺[BF₄]^?), [C₂mim]⁺[BF₄]^?–DBT, [C₄mim]⁺[BF₄]^?–DBT, [C₆mim]⁺[BF₄]^?–DBT and [C₈mim]⁺[BF₄]^?–DBT systems are optimized systematically at the B3LYP/6-31G(d,p) level, and the most stable geometries are obtained by NBO and AIM analyses. The results indicate that DBT and imidazolium rings of ionic liquids are parallel to each other. It is found that the [BF₄]^? anion prefers to be located close to a C1–H9 proton ring in the vicinity of the imidazolium ring and the most stable gas-phase structure of [C _n mim]⁺[BF₄]^? has four hydrogen bonds between [C _n mim]+ and [BF₄]?. There are hydrogen bonding interactions, π–π and C–H–π interactions between [C₈mim]⁺[BF₄]^? and DBT, which is confirmed by NBO and AIM analyses. The calculated interaction energies for the studied ionic liquids can be used to interpret a better extracting ability of [C₈mim]⁺[BF₄]^? to remove DBT, due to stronger interactions between [C₈mim]⁺[BF₄]^? and DBT, in agreement with the experimental results of dibenzothiophene extraction by [C _n mim]⁺[BF₄]^?.     

An Isolable Potassium Salt of a Borasilene–Chloride Adduct

Among the variety of isolable compounds with multiple bonds involving silicon, examples of compounds that contain silicon–boron double bonds (borasilenes) still remain relatively rare. Herein, we report the synthesis of the potassium salt of a chloride adduct of borasilene 1 ([ 2 ]⁻), which was obtained as an orange crystalline solid. Single‐crystal X‐ray diffraction analysis and reactivity studies on [ 2 ]⁻ confirmed the double‐bond character of the Si=B bond as well as the reduced Lewis acidity, which is due to the coordination of Cl⁻ to the boron center. A thermal reaction of [ 2 ]⁻ afforded a bicyclic product by formal intramolecular C−H insertion across the Si=B bond of 1 , which was corroborated by a theoretical study.     

[F]Fluoromethyl iodide ([F]FCH2I): preparation and reactions with phenol, thiophenol, amide and amine functional groups

In this study, we report the synthesis and reactivity of [¹⁸F]fluoromethyl iodide ([¹⁸F]FCH₂I) with various nucleophilic substrates and the stabilities of [¹⁸F]fluoromethylated compounds. [¹⁸F]FCH₂I was prepared by reacting diiodomethane (CH₂I₂) with [¹⁸F]KF, and purified by distillation in radiochemical yields of 14-31% (n = 25). [¹⁸F]FCH₂I was stable in organic solvents commonly used for labeling and aqueous solution with pH 1-7, but was unstable in basic solutions. [¹⁸F]FCH₂I displayed a high reactivity with various nucleophilic substrates such as phenol, thiophenol, amide and amine. The [¹⁸F]fluoromethylated compounds synthesized by the reactions of phenol, thiophenol and tertiary amine with [¹⁸F]FCH₂I were stable for purification, formulation and storage. In contrast, the [¹⁸F]fluoromethylated compounds synthesized by the reactions of primary or secondary amines, and amide with [¹⁸F]FCH₂I were too unstable to be detected or purified from the reaction mixtures. Defluorination of these [¹⁸F]fluoromethyl compounds was a main decomposition route.     

Polymeric structures in the metal complexes of 5-sulfosalicylic acid: The rubidium(I), caesium(I) and lead(II) analogues

The complexes of 3-carboxy-4-hydroxybenzenesulfonic acid (5-sulfosalicylic acid, H₃SSA) with rubidium(I), caesium(I) and lead(II) have been synthesized and characterized using single-crystal X-ray methods at 130 K. The rubidium(I) complex 1, [Rb₃(H₂SSA)(HSSA)(H₂O)₄]_n, is an unstable hydrate variant of a previously described complex [Rb(H₂SSA)(H₂O)]_n, and comprises three independent and different seven-coordinate metal polyhedra interlinked through oxygen donors of the sulfonate, carboxylate and phenolate groups of the 5-sulfosalicylate ligands (one of which is dianionic, the other monoanionic), and one bridging water, giving a three-dimensional hydrogen-bonded framework polymer structure. The anhydrous caesium(I) complex 2 [Cs(H₂SSA)]_n, which has been previously described in a room-temperature determination, has a three-dimensional framework polymer structure based on an irregular Cs–O₉ repeating unit. Complex 3 with lead(II), [Pb(H₂SSA)₂(H₂O)]_n, forms helical step-polymer ribbon substructures having an irregular Pb–O₇ coordination centre comprising a single monodentate water and six sulfonate-O donors bridging three separate metals. The carboxylic acid and phenol substituent groups of the 5-sulfosalicylate ligand link the ribbons peripherally through hydrogen bonds, giving a three-dimensional layered framework polymer structure.     

Synthesis, structural elucidation and biological activities of organotin(IV) derivatives of (E)-3-(4-methoxyphenyl)-2-(4-chlorophenyl)-2-propenoic acid

A new series of di- and tri-organotin(IV) compounds with the general formula R_4?n SnL _n , where R?=?Me (1,2), Et (3), n-Bu (4,5), n-Oct (6), Ph (7) and L?=?(E)-3-(4-methoxyphenyl)-2-(4-chlorophenyl)-2-propenoate, were synthesized by reaction of silver salt of ligand or ligand acid with diorganotin dichloride/oxide and triorganotin chloride in 2:1 and 1:1 molar ratio, respectively. These compounds were characterized by elemental analyses, FT-IR, multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR and mass spectrometry. The spectroscopic results revealed that all the diorganotin(IV) compounds possess trigonal bipyramidal structures in solution and octahedral geometry in the solid state around the tin atom. A linear polymeric trigonal bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non-coordinating solvents has been proposed for the triorganotin(IV) compounds. All synthesized compounds were tested in vitro against a number of microorganisms to assess their biocidal activity. These studies revealed that ligand acid and some of its organotin compounds show promising activity against different strains of bacteria and fungi but lowered than reference drugs.     

Dimensions of the Ozonide Anion in M([18]crown‐6)O3·x NH3 with M = K (x = 2), Rb (x = 1) and Cs (x = 8)

Reaction of alkali metal ozonides (KO₃, RbO₃ and CsO₃) with [18]crown‐6 in liquid ammonia yields compounds of the composition M([18]crown‐6)O₃·x NH₃ with M = K (x = 2), Rb (x = 1) and Cs (x = 8). The large intermolecular distance between adjacent radical anions in these compounds leads to almost ideal paramagnetic behavior according to Curie's law. Discrepancies concerning the structure of the ozonide anions in the K and Cs compound compared to a former investigation on Rb([18]crown‐6)O₃·NH₃ have been resolved by means of DFT calculations and a single‐crystal structure redetermination.     

Copper(I) Complexes of Bithiazoles

Several new copper(I) complexes of a group of bidentate bithiazole ligands have been isolated. The compounds prepared are bis(2,2′-dimethyl-4,4′-bithiazole)copper(I) perchlorate ([Cu(me-b)₂]ClO₄), bis(4,4′-dimethyl-2,2′-bithiazole)copper(I) perchlorate ([Cu(me-i)₂]ClO₄), bis(2,2′-diphenyl-4,4′-bithiazole) copper(I) perchlorate ([Cu(ph-b)₂]ClO₄), bis(4,4′-diphenyl-2,2′-bithiazole)copper(I) perchlorate ([Cu(ph-i)₂]ClO₄), bis(4,4′,5,5′-tetraphenyl-2,2′-bithiazole)-copper(I) perchlorate ([Cu(ph₄-i)₂]ClO₄, bis(2,2′-bithiazole)copper(l) perchlorate ([Cu(i)₂]CIO₄), 2,2′-bithiazolecopper(I) perchlorate ([Cu(i)ClO₄), (2,2′-bithiazole)bis(triphenylphosphinesulfide)copper(I) perchlorate ([Cu(i)(SPph₃)₂]ClO₄,(2,2′-bithiazole)bis-( triphenylphosphine)copper(I) perchlorate ([Cu(i)(Pph₃)₂]ClO₄), and (4,4′-bithiazole)bis(triphenylphosphine) copper(I) perchlorate ([Cu(b)(Pph₃)₂]ClO₄). Several synthetic techniques were required including one developed in this work which involved the conversion of [Cu(Pph₃)₄]ClO₄ into the thiophosphine complex by reaction with sulfur and subsequent use of this as a labile precursor complex. Optical spectra of the complexes indicate extensive solution dissociation. Several of the complexes ([Cu(ph-b)₂]ClO₄, [Cu(ph-i)₂]CIO₄, and [Cu(i)(Pph₃]ClO₄) were photoluminescent in the solid; one ([Cu(ph-b)₂]ClO₄) showed extensive loss of emission during irradiation. Most of the complexes prepared here appear to bind through the thiazole nitrogen atoms. However, infrared evidence suggests that in two of the complexes thiazole sulfur atoms participate in the bonding.     

Luminescence properties of three structures built from 3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate and alkaline metals (Na,K and Rb)

The structures of three salts of 3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate with alkali metals (Na, K and Rb) are related to their luminescence properties. The Rb salt, rubidium(I) 3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate, Rb⁺·C₈HN₄O₂⁻, is isomorphous with the previously reported potassium salt. For the Na compound, sodium(I) 3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate dihydrate, Na⁺·C₈HN₄O₂⁻·2H₂O, two independent sodium ions, located on inversion centers, are coordinated by four water molecules each and additionally by two cyano groups for one and two carbonyl groups for the other. The luminescence spectra in solution are unaffected by the nature of the cation but vary strongly with the dielectric constant of the solvent. In the solid state, the emission maxima vary with structural features; the redshift of the maximum luminescence varies inversely with the distance between the stacked anions.     

Synthesis and structural characterization of monomeric and polymeric supramolecular organotin(IV) 4-chlorophenylethanoates

Four monomeric [n-Bu₂SnL₂ (1), Et₂SnL₂ (2), Me₂SnL₂ (3), and n-Oct₂SnL₂ (7)] and three polymeric {[n-Bu₃SnL]_n (4), [Me₃SnL]_n (5), and [Ph₃SnL]_n (6)} organotin(IV) carboxylates, where L?=?4-chlorophenylethanoate, were synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Compounds 2 and 5 were also analyzed by X-ray single-crystal analysis showing monomeric and zigzag structures, respectively. Two types of O…H (2.641?Å) and Cl…H (2.943?Å) non-covalent interactions generate a 2-D supramolecular structure for 2. Layer-by-layer supramolecular structure was observed for 5 in which polymeric chains are connected via non-covalent interactions {Cl…H (2.869?Å), H…π (2.899?Å)}, and unconventional dihydrogen {H…H (2.381?Å)} interactions.     

New fluorochromatouranylates of alkali metals: Synthesis and structure

Four new fluorochromatouranylates, namely, K[UO₂(CrO₄)F] · 1.5H₂O (I), Rb[UO₂(CrO₄)F] · 1.5H₂O (II), Rb[UO₂(CrO₄)F] · 0.5H₂O (III), and Cs[UO₂(CrO₄)F] · 0.5H₂O (IV), have been synthesized, and their crystallographic characteristics have been determined. All the compounds crystallize in monoclinic system, space group P2₁/c, with the unit cell parameters a = 13.1744(5) Å, b = 9.4598(3) Å, c = 13.0710(4) Å, β = 103.746(1)°, Z = 4, R = 0.0235 (I); a = 13.5902(7) Å, b = 9.5022(4) Å, c = 13.2271(6) Å, β = 102.914(2)°, Z = 4, R = 0.0247 (II); a = 24.7724(8) Å, b = 12.6671(4) Å, c = 9.4464(3) Å, β = 97.661(1)°, Z = 8, R = 0.0448 (III); a = 25.725(1) Å, b = 12.8261(5) Å, c = 9.4929(4) β = 97.208(1)°, Z = 8 (IV). The pairs of compounds I and II and compounds III and IV are isostructural. Crystals of compounds I–III have been subjected to complete X-ray diffraction study. It has been established that the structures of compounds I–III are built of [UO₂(CrO₄)F] _n ^n? layers, which are parallel to the (100) plane and linked into a framework by alkali-metal cations located between layers, together with water molecules. The effect of topological and geometric isomerism on the structural features of 34 known uranyl compounds of the AT³M² crystallochemical group, to which the studied compounds I–III also belong, is discussed.     

Alkali‐Metal meta‐Hydroxyphenolates: Syntheses and Crystal Structures from Powder X‐Ray Diffraction

M[m‐C₆H₄O(OH)] (M = Li—Cs) have been obtained as highly air‐ and moisture‐sensitive powders from reaction mixtures of the appropriate alkali metals and resorcinol in thf. Both the potassium and rubidium compounds were structurally characterized by means of powder X‐ray diffraction using the Simulated Annealing method and the Rietveld profile refinement technique including C—C/C—O bond distance and C—C—C angle restraints. K[m‐C₆H₄O(OH)] (orthorhombic P2₁2₁2₁) forms infinite alternating chains of meta‐hydroxyphenolate anions connected by K—O bonds and short charge‐assisted hydrogen bonds, thereby generating a three‐dimensional network of corrugated layers similar to the structure of pure resorcinol. The potassium cations are surrounded by a triangle of oxygen and, moreover, coordinated by six adjacent phenylene rings to form a distorted octahedron. The complex crystal structure of Rb[m‐C₆H₄O(OH)] (monoclinic Pa) is characterized by layers of hydrogen‐bonded meta‐hydroxyphenolate triple units separated by corrugated rubidium layers. The three crystallographically different Rb atoms are coordinated by three, four, and five oxygens with irregular polyhedra, and the rubidiums are also involved in further electrostatic interactions by up to eight phenylene rings.