The First Organically Templated Layered Uranium(IV) Fluorides: (H3N(CH2)3NH3)U2F10⋅2 H2O, (H3N(CH2)4NH3)U2F10⋅3 H2O,and (H3N(CH2)6NH3)U2F10⋅2 H2O

A new series of layered organically templated uranium(IV ) fluorides has been exclusively synthesized under hydrothermal conditions. The unprecedented materials contain [U₂F₁₀]²⁻ anionic layers that are separated by charge balancing cationic templates and occluded water molecules (see structure depicted). The templates can be fully ion-exchanged for a variety of metals (Na⁺, K⁺, and Co²⁺) at room temperature.     

Syntheses et isomerisation de complexes de la serie des derives halocarbonyle due fer: [FeX(CO)5−nLn]+, FeX2(CO)4−nLn et [FeX3(CO)3]- (L = PMe3; n = 1, 2, 3; X = Cl,Br, I)

The synthesis of a number of neutral, cationic and anionic halocarbonyl complexes of iron having the formula [FeX_m(CO)_6?m?nL_n]^2?m is described. The determination of their molecular configuration by infrared, NMR and dipole moment measurements allowed the study of several of their photochemical isomerization reactions, the mechanism of these reactions is explained in some cases by the intermediary formation of cationic complexes.     

Perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) as a precursor of new gold complexes

The perchlorato ligand of perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) can easily be displaced by different types of ligands. Neutral complexes are obtained by adding anionic ligands (N^?₃, HCO^?₃, while cationic complexes are obtained by adding neutral monodentate ligands (OPPh₃, OAsPh₃, ONC₅H₅, ONC₉H₇, NC₉H₇, PEt₃, PBu₃, PPh₂Me). Only with very weak σ-donors (SO₂, CO₂, NC₅F₅, NC₅Cl₅) does no reaction take place. The addition of neutral bidentate ligands leads to cationic gold(III) complexes with diphosphines and diarsines, whereas nitrogen- or oxygen-donors give rise to reductive elimination reactions which lead to gold(I) complexes.No reaction takes place with mono-olefins while cyclopolyolefins give rather unstable gold(I) complexes which readily decompose. Only the gold(I) complex with 1,5-cyclooctadiene can be isolated.     

Three Lead(II) Complexes in One Coordination Polymer, [Pb(TpyCl)Cl][Pb(TpyCl)Cl2][PbCl3](CH3OH)

[Pb(TpyCl)Cl][Pb(TpyCl)Cl₂][PbCl₃](CH₃OH) ( 1 ), a new coordination polymer of divalent lead with the ligand 4′‐chloro‐2,2′:6′,2"‐terpyridine (TpyCl), was obtained as single crystals by the branched tube method. The crystal structure contains three complexes, the cationic [Pb(TpyCl)Cl]⁺, the neutral [Pb(TpyCl)Cl₂] and the anionic [PbCl₃]^–, which are connected through bridging chlorides and hydrogen bonds to a two‐dimensional coordination polymer. In all three complexes, the arrangement around the Pb²⁺ ion suggests the existence of a stereoactive lone pair.     

The geometric, energetic, and electronic properties of charged phosphorus-doped silicon clusters, PSi n +/PSi n ? (n?=?1�C8)

Charged phosphorus-doped small silicon clusters, PSi _n ⁺/PSi _n ^? (n?=?1?8), have been investigated using the B3LYP/6-311+G* level Kohn?CSham density functional theory (KS-DFT) method. For comparison, the geometries of neutral PSi _n clusters were also optimized at the same level, though most of them have been previously reported. According to our results, cationic PSi _n ⁺ clusters have ground state structures similar to those of pure silicon clusters Si _n+1, with the exception of n?=?5. For anionic PSi _n ^?, most of the lowest-energy structures are in accord with Wade??s 2N+2 rule for closed polyhedra: PSi₄ ^?, PSi₅ ^?, PSi₆ ^?, and PSi₈ ^?, respectively, favor the trigonal bipyramid, tetragonal bipyramid, pentagonal bipyramid, and tricapped trigonal prism (TTP) structures, corresponding to Wade??s 2N+2 rule with N?=?5, 6, 7, and 9. The structures tend to contract when the cationic species is reduced initially to the neutral species and subsequently to the anionic species, implying a strengthening interaction between atoms within the clusters on one and two electron reductions of the cationic species to the neutral and anionic species, respectively. The relative order of stability of the PSi _n ⁺/PSi _n ^? isomers differs from that of the PSi _n isomers. Cluster stability was also analyzed by adiabatic ionization potentials (AIP), adiabatic electron affinities (AEA), binding energies (BE), second-order energy differences (?₂E), and HOMO-LUMO gap values. The results indicate that PSi₄ ^? and PSi₇ ^? clusters are more stable than their neighboring anionic clusters and would be potential species for further mass spectrometric measurements.     

Isolation and characterization of (Ar)(F)B(OR)2Cs and (PN)CuAr complexes. Involvement of cationic copper(I) species during transmetalation of arylboron reagents with (PN)CuF

We report the synthesis and characterization of novel anionic arylfluoroborate, three-coordinate ligated arylcopper(I) and cationic ligated copper(I) complexes. We show through in situ ¹⁹F NMR monitoring that neutral arylboronate ester is more kinetically competent than anionic arylfluoroborate for transmetalation with (PN)CuF (PN = o-(di-tert-butylphosphino)-N,N-dimethylaniline). The transmetalation of the neutral arylboronate ester proceeds via a two-step process involving a cationic copper(I) species wherein an anionic arylfluoroborate is generated in situ as a competent aryl group transferring reagent.     

Theoretical insight of nitric oxide adsorption on neutral and charged Pdn (n = 1–5) clusters

Density functional theory (DFT) calculations within the framework of generalized gradient approximation have been used to systematically investigate the adsorption of nitric oxide (NO) molecule on neutral, cationic, and anionic Pd_n (n = 1–5) clusters. NO coordinate to one Pd atom of the cluster by the end‐on mode, where the tilted end‐on structure is more favorable due to the additional electron in the π* orbital. On the contrary, in the neutral and cationic Pd₂ system, NO coordinates to the bridge site of cluster preferably by the side‐on mode. Charge transfer between Pd clusters and NO molecule and the corresponding weakening of N? O bond is an essential factor for the adsorption. The N? O stretching frequency follow the order of cationic > neutral > anionic. Binding energy of NO on anionic clusters is found to be greater than those of neutral and cationic clusters. © 2015 Wiley Periodicals, Inc.     

Structural and Electronic Properties in Titanium-Doped Stannum Clusters: Comparison with Their Anions and Cations

The neutral, anionic, and cationic Sn_nTi^{(0, ±1)} (n?=?1–10) units are researched computationally using a density functional theory. The optimized geometries of Sn_nTi^{(0, ±1)} clusters illustrate that the most stable structures between the neutral, anionic, and cationic clusters keep the similar structures when n?=?1, 2, 4, 5, 9,10, however, we find that the obtained most stable clusters of the size n?=?3, 6, 7, 8 are different. From the optimized results a systematic analysis is carried out to obtain the relative stabilities, electronic properties, and natural population analysis of Sn_nTi^{(0, ±1)} clusters. The relative stabilities are investigated by analyzing the binding energies, fragmentation energies, and the second order energies difference of Sn_nTi^{(0, ±1)} clusters, the results show that the binding energies of anionic clusters are obviously larger than those of neutral and cationic clusters. The HOMO–LUMO gap, the adiabatic electron affinity, vertical electron detachment energy, adiabatic ionization potential energy, and vertical ionization potential energy respond the electronic property, we obtain that the Ti atom changes the electron structures of stannum clusters. To discuss reliable charge transfer information from Sn_nTi clusters to Sn_nTi^? clusters and Sn_nTi⁺ clusters, the natural population analysis of neutral, anionic, and cationic Sn_nTi^(0,±1) clusters are calculated.     

High-voltage electrophoresis of106Ru—Sea water systems

The physicochemical behaviour of¹⁰⁶Ru chloro and nitrosyl-nitrato complex species in sea water atpH 8 were investigated by high-voltage electrophoresis. The¹⁰⁶Ru chloro complexes in the sea water system were separated into at least 10 anionic species, one ‘neutral’ hydrolytic species and 2 cationic species. The¹⁰⁶Ru nitrosylnitrato complexes in sea water were separated into 3 anionic species, one ‘neutral’ species and 3 cationic species. The absolute electrophoretic mobilities of the separated¹⁰⁶Ru species in sea water were found to be constant during the aging period from 48 hrs up to 1 080 hrs. In the initial period up to 48 hrs of aging, considerable physicochemical changes were observed for both the chloro and nitrosyl-nitrato forms of¹⁰⁶Ru, as a result of the initial stabilization of the system. The aging of the systems up to 1 080 hrs was followed quantitatively by radiometric counting of the separated soluble species. The significant decrease of the radioactivity of the soluble systems during the aging was found to be due to the precipitation of the ruthenium species. The results obtained are discussed with regard to the consequences that¹⁰⁶Ru waste disposal in the sea may have on the marine environment.     

Electrochemical activation of acyl ligands in organometals. ESR studies of acetyl- and benzoyliron(III) complexes

The anodic oxidation of two series of acyliron(II) complexes, the neutral CpFe(CO)₂COR(I) and the anionic CpFe(CO)(CN)COR^? (II) where R = CH₃ and C₆H₅, are examined in acetonitrile solutions. The cyclic voltammograms of II are reversible, whereas those of I are irreversible even at sweep rates as high as 10 V s^?1. The neutral CpFe^III (CO)(CN)COCH₃ radical is sufficiently stable at 20°C to examine its ESR spectrum, as well as the kinetics and mechanism of thermal decomposition to afford acetone in high yields. However the cation-radical CpFe^III(CO)₂COCH⁺₃ from I is too reactive to observe directly, and it undergoes rapid solvolytic substitution in the presence of ethanol to afford ethyl acetate. The distinction between neutral and cationic acyliron(III) radicals is discussed in the context of acyl activation of organometals by electrochemical methods.     

Protic Anions [H(B12X12)]− (X=F,Cl, Br,I) That Act as Brønsted Acids in the Gas Phase

The acidity of protic cations and neutral molecules has been studied extensively in the gas phase, and the gas‐phase acidity has been established previously as a very useful measure of the intrinsic acidity of neutral and cationic compounds. However, no data for any anionic acids were available prior to this study. The protic anions [H(B₁₂X₁₂)]^? (X=F, Cl, Br, I) are expected to be the most acidic anions known to date. Therefore, they were investigated in this study with respect to their ability to protonate neutral molecules in the gas phase by using a combination of mass spectrometry and quantum‐chemical calculations. For the first time it was shown that in the gas phase protic anions are also able to protonate neutral molecules and thus act as Brønsted acids. According to theoretical calculations, [H(B₁₂I₁₂)]^? is the most acidic gas‐phase anion, whereas in actual protonation experiments [H(B₁₂Cl₁₂)]^? is the most potent gas‐phase acidic anion for the protonation of neutral molecules. This discrepancy is explained by ion pairing and kinetic effects.     

A new three‐dimensional neutral framework of lanthanum oxalate: [La2(C2O4)3(DMF)(H2O)3]n

In the title complex, poly[triaquabis(dimethylformamide)di‐μ₃‐oxalato‐μ₂‐oxalato‐dilanthanum(III)], [La₂(C₂O₄)₃(C₃H₇NO)(H₂O)₃]_n, both La ions are coordinated by nine O atoms, forming slightly distorted tricapped trigonal prisms. The two La ions, the terminal water O atom, and the O and N atoms of the dimethylformamide molecule reside on twofold rotation axes, giving the two La‐centered coordination geometries twofold or pseudo‐twofold symmetries. The two oxalate ligands, one of which rests on a center of inversion at the mid‐point of the C—C bond, adopt different bridging modes, connecting with the La ions to form two types of lanthanide oxalate chains, i.e. anionic {[La(C₂O₄)₂(DMF)(H₂O)₂]ⁿ⁻}_n (DMF is dimethylformamide) and cationic zigzag {[La(C₂O₄)(H₂O)]ⁿ⁺}_n, respectively. Each zigzag cationic chain is linked to four adjacent anionic chains via the bridging oxalate anions, and each anionic chain connects with four zigzag cationic chains, constructing a three‐dimensional neutral framework.     

A Microporous Anionic Metal–Organic Framework for Sensing Luminescence of Lanthanide(III) Ions and Selective Absorption of Dyes by Ionic Exchange

Herein, a novel anionic framework with primitive centered cubic (pcu) topology, [(CH₃)₂NH₂]₄[(Zn₄dttz₆)Zn₃]?15 DMF?4.5 H₂O, ( IFMC‐2 ; H₃dttz=4,5‐di(1H‐tetrazol‐5‐yl)‐2H‐1,2,3‐triazole) was solvothermally isolated. A new example of a tetranuclear zinc cluster {Zn₄dttz₆} served as a secondary building unit in IFMC‐2 . Furthermore, the metal cluster was connected by Zn^II ions to give rise to a 3D open microporous structure. The lanthanide(III)‐loaded metal–organic framework (MOF) materials Ln³⁺@IFMC‐2 , were successfully prepared by using ion‐exchange experiments owing to the anionic framework of IFMC‐2 . Moreover, the emission spectra of the as‐prepared Ln³⁺@IFMC‐2 were investigated, and the results suggested that IFMC‐2 could be utilized as a potential luminescent probe toward different Ln³⁺ ions. Additionally, the absorption ability of IFMC‐2 toward ionic dyes was also performed. Cationic dyes can be absorbed, but not neutral and anionic dyes, thus indicating that IFMC‐2 exhibits selective absorption toward cationic dyes. Furthermore, the cationic dyes can be gradually released in the presence of NaCl.     

Adsorption of CO on oxygen preadsorbed neutral and charged gas phase Pd4 clusters: A density functional study

We present the results of a density functional calculation on adsorption of O₂, CO, and their coadsorption at various sites of neutral, cationic, and anionic Pd₄ clusters. For all the clusters, the dissociative adsorption of oxygen sitting on Pd bridge sites is found to be preferable. Both O₂ and CO binding energies are found to be higher for the anionic Pd₄ cluster followed by cationic and neutral cluster. However, binding energies of O₂ or CO in the coadsorption complexes follow the trend: anionic > neutral > cationic. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010     

Hydrolysis of hydro(pyrrolyl-1)borates

The hydrolysis of hydro(pyrrolyl-l)borates ([BH_n(NC₄H₄)_4-n]⁻, n = 1,2,3) can be treated as a kinetically one-step reaction outside of the mildly acidic region. In strongly acidic medium the hydrolysis takes place in a stepwise manner; the intermediates (boranes and the cationic boron compounds) being hydrolyzed more slowly than the borate anion. In the first step of the hydrolysis of [BH₃(NC₄H₄)]⁻ the B---H bond, while in case of [BH₂(NC₄H₄)₂]⁻ and [BH(NC₄H₄)₃]⁻ the B---N bond is breaking.In neutral and mildly alkaline medium, the hydrolysis is a general acid catalyzed reaction (A---S_E2 mechanism). It becomes to a special H⁺-ion catalyzed reaction (A-1 mechanism) in strongly alkaline region since the protonated intermediate can be reversed to the original borate upon reaction with the OH⁻ ion. The hydrolysis presumably takes place through an intermediate which is protonated on the pyrrolyl nitrogen. Concomitant to the hydrolysis an isotopic exchange reaction was observed on the C_α and C_β atoms of the pyrrolyl group in heavy water. In the hydrolysis of the [BH₃(NC₄H₄)]⁻-anion the N-protonated intermediate is assumed to be able to reverse to the original borate even in acidic or neutral region, at least in part.     

A convenient synthetic route to new bis(arenediazo) complexes of molybdenum and tungsten

Complexes of the type [(C₅H₅)Mo(N₂Ar)(N₂Ar′)(PPh₃)] [PF₆] have been prepared and shown to be useful starting materials for the synthesis of a variety of neutral, cationic or anionic compounds containing [cis-Mo(N₂Ar)(N₂Ar′)]²⁺ units.     

Mechanism of oxidation of iron(II) chelates by hexavalent chromium and heptavalent manganese in aqueous sulfuric acid and micellar media - a kinetic approach

Summary Oxidation of the Fe^II chelates [FeL] (L = phen or bipy) by Cr^VI and Mn^VII in H₂SO₄ medium was found to proceed through the formation of a bimetallic insertion complex which decomposes in the slow step, followed by electron transfer from [FeL] to the oxidant. The reactions are catalysed by both anionic and non-ionic micelles [SDS and triton-x (Tx), respectively]. A mechanism is suggested involving electrostatic stabilization of the cationic forms of the Fe^II chelates by anionic SDS and the partial anionic character of polyoxyethylene moiety of Tx, respectively. The marginal catalysis of cationic micelles (CTAB) is attributed to co-anion-micellar interactions.     

Polyvalent perfluoroorgano- and selected polyfluoroorgano-halogen(III and V) compounds

This review compiles important aspects of the chemistry of polyvalent perfluoroorganohalogen(III and V) compounds of the last three decades and reports on distinctions which are worth mentioning in comparison with non-fluorinated polyvalent organohalogen(III and V) analogues. Besides general synthetic paths to neutral (R_FHalX₂, (R_F)₂IX, (R_F)₃I, and R_FHalX₄), cationic ([R_F(R′)Hal]Y and [R_F(R′)HalF₂]Y), and anionic (M[R_FHalX₃] and M[(R_F)₂HalX₂]) derivatives of iodine and bromine, transformations at the halogen centre of those polyvalent compounds and selected applications and their use as reagents are referred. Trends of ¹⁹F and ¹³C NMR spectroscopic properties of prototypes of polyvalent perfluoroorgano-iodine and -bromine compounds are compiled and interpreted. Structural features of characteristic perfluoroalkyl-, pentafluorophenyliodine(III and V), and few -bromine(III) compounds are presented and compared.     

NMR Study of the Reactions of Tin(II) Difluoride and Antimony(III) Trifluoride with Niobium Pentachloride

The reactions of SnF₂and SbF₃with NbCl₅in acetonitrile or dimethyl sulfoxide were studied by ¹⁹F, ⁹³Nb, and ¹¹⁹Sn NMR spectroscopy. The products of reaction in acetonitrile are anionic, while those in di-methyl sulfoxide are neutral octahedral niobium chlorofluoride complexes. Tin(II) difluoride and antimony(III) trifluoride are powerful sources of fluoride ions in the preparation of metal chlorofluoride and fluoro complexes.     

Tetrathioureamercury(II) tetrathiocyanatomanganate(II)

In the title complex, [Hg(CH₄N₂S)₄][Mn(NCS)₄], the Hg and Mn atoms sit at special positions with symmetry and are tetrahedrally coordinated to four thio­urea (TU) S and four thio­cyanate (SCN) N atoms, respectively. The structure consists of discrete cationic and anionic [Hg(TU)₄]²⁺ and [Mn(SCN)₄]²⁻ complexes, and weak N_TU—H⃛S_SCN hydrogen-bond bridges exist between these complexes.