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C8H15NO4S, orthorhombic, P212121 (no. 19), a = 5.0215 (3) Å, b = 7.0392 (5) Å, c = 28.0593 (19) Å, V = 991.82 (11) Å3, Z = 4, R gt(F) = 0.0462, wR ref(F 2) = 0.0899, T = 100 K.

The reactivity of two metallocene aryloxide U(III) complexes, [(C5Me5)2U(O-Ar)], Ar = 4-tBuC6H4, 1; Ar = 2,6-tBu2-4-CH3C6H2(BHT), 3, with CO2and CS2has been investigated. The reaction of 1 with CO2produces a bridging oxo complex, [{(C5Me5)2(4-tBuC6H4-O)U}2(μ2-O)], 4, while 3 with CO2results in reductive disproportionation to form the bridging carbonate species, [{(C5Me5)2(BHT)U}2(μ2-κ2:η1-CO3)], 5. The difference in reactivity can be attributed to the steric properties of the ligand because the reaction of 3 with an oxo-delivering agent yields a U(V) terminal oxo complex, [(C5Me5)2(BHT)U═O], 6. Reduction of CS2to form a bridging (CS2)2-ligand, [{(C5Me5)2(tBuC6H4-O)U}2(μ2-CS2)], 7, is observed with 1, while the reaction of 3 with CS2also produces a bridging (CS2)2-reduced ligand complex, followed by C-H bond activation of a methyl group from one (C5Me5)1-ring, [(C5Me5)2(BHT)U{μ2-C(H)S2}U(C5Me4CH2)(C5Me5)(BHT)], 8. All compounds are characterized by NMR and IR spectroscopy, and their solid-state structures are determined by X-ray crystallography.

CH8N2O3S, monoclinic, P21/c (no. 14), a = 9.7583 (16) Å, b = 5.4033 (9) Å, c = 10.4729 (17) Å, β = 110.483 (4)°, V = 517.29 (15) Å3, Z = 1, Rgt(F) = 0.0225, wRref(F2) = 0.0649, T = 150 K.

To extend organoactinide chemistry beyond uranium, reported here is the first structurally characterized transuranic hydrocarbyl complex, Np[η4 -Me2 NC(H)C6 H5 ]3 (1), from reaction of NpCl4 (DME)2 with four equivalents of K[Me2 NC(H)C6 H5 ]. Unlike the UIII species, the neptunium analogue can be used to access other NpIII complexes. The reaction of 1 with three equivalents of HE2 C(2,6-Mes2 -C6 H3 ) (E=O, S) yields [(2,6-Mes2 -C6 H3 )CE2 ]3 Np(THF)2 , maintaining the trivalent oxidation state.

Synthesis of cerium yldiide complexes and their reactivity with CO is demonstrated. In the case of the sulphur-tethered yldiide, the ketenyl complex is formed with release of PPh3, while Ph3PCCO is formed along with a sulfinato ligand in the case of the tosyl-substituted yldiide. Computational analysis shows that this diverging reactivity is due to the stability of the two isomers in the first step of each mechanism. [ABSTRACT FROM AUTHOR]

C15H15N3O3, triclinic, P 1‾ $\overline{1}$ (no. 2), a = 9.0752(2) Å, b = 9.1969(2) Å, c = 9.9519(2) Å, α = 112.7059(8)°, β = 92.4309(8)°, γ = 115.2776(7)°, V = 671.16(3) Å3, Z = 2, R gt(F) = 0.0347, wR ref(F 2) = 0.1113, T = 100 K.

C15H15N3O2, orthorhombic, Pca21 (no. 29), a = 7.9831(2) Å, b = 10.6486(3) Å, c = 15.7222(4) Å, V = 1336.53(6) Å3, Z = 4, Rgt(F) = 0.0340, wRref(F2) = 0.0799, T = 100 K.

The bis(yldiide) mercury complex, (L–Hg–L) [L = C(PPh3)P(S)Ph2], is prepared from the corresponding potassium yldiide and used to access the first substituted yldiide actinide complexes [(C5Me5)2An(L)(Cl)] (An = U, Th) via salt metathesis. Compared to previously reported phosphinocarbene complexes, the complexes exhibit long actinide–carbon distances, which can be explained by the strong polarization of the π-electron density toward carbon. [ABSTRACT FROM AUTHOR]

We report on a two-dimensional hexagonal "honeycomb" network comprising barium-seamed metal–organic nanocapsules involving a hexameric assembly of pyrogallol[4]arene ligands. The incorporated barium ions act as spacers to generate a solvent-accessible void, hierarchical self-assembly having an individual void volume near 13 000 Å3. This work illustrates the surprising chemistry that remains to be discovered by integrating large or classically non-reactive metal ions within supramolecular assemblies, networks, and organic nanocapsules. [ABSTRACT FROM AUTHOR]

The morphologies of sixteen crystal structures of ten symmetrical Xpara–Ph–(Me)C＝N–N＝C (Me)–Ph–Xpara azines: 1 (Cl), 2 (Br), 3 (I), 4 (OH), 5 (PhO), 6 (CF3), 7 (F), 8 (Me), 9 (NO2), and 10 (PrO) are described. All the azines crystallize forming idioteloamphiphile monolayers (IAMs) and their morphologies fall into the two main classes of "flat" and "shiplap" depending on the lateral offsets between next-neighbors in the monolayer. Ab initio studies show that the (E,E)-configured p-disubstituted acetophenone azines are C2-symmetric in the gas phase and that the azine and phenyl twists are correlated and give rise to P- and M-chirality. The crystal structures of 1–10 are true racemates and, remarkably, the majority feature asymmetric (C1) azines rather than dissymmetric (C2) azines. To understand the origin of the symmetry reduction, we studied the supramolecular structures and IAM characteristics of the five azines that crystallize with a flat morphology 1-I (Cl), 2-Ia (Br), 3 (I), 5 (PhO), and 10 (PrO). The deep analysis of chloroazine 1-I shows that the symmetry reduction is the result of qualitatively different coordination environments of the two chloroarene moieties and presents a case of crystal environment induced symmetry reduction (CEISR). The crystal structure of 1-I is of the type "AABB Kick/Flat" and the advantages of the double-stripe motif are explained. Careful analysis of the crystal structure showed arene–arene T-contacts of the types edge-to-face (e‖f), face-to-edge (f‖e), and face-to-face (f‖f), a new arene–azine interaction (e‖Az), and H⋯Cl, Cl⋯π, and Cl⋯Cl contacts. Intra- and interlayer interaction inventory analyses show in a compelling fashion that the arenes Ai and As in each azine engage in qualitatively different intermolecular interactions. To demonstrate the usefulness of the interaction inventory analysis, we also compare and contrast the crystal environments of the C1-symmetric azines in crystals of 2-Ia (Br) and 10 (PrO) and the C2-symmetric azines in crystals of 3 (I) and 5 (PhO). Intermolecular interactions are quantified using Hirshfeld surface analyses, pairwise interaction energies, and electrostatic potential maps. We will also describe a fast method for the detection of CEISR based on N⋯H Hirshfeld 2D fingerprint plots. [ABSTRACT FROM AUTHOR]

Polar and non-polar polymorphs of (PhO, F)-azine are reported. Both polymorphs feature identical 2-D perfectly parallel-aligned beloamphiphile monolayers (PBAMs). The striking contrast between the polymorphs is the stacking of the PBAMs in the third dimension. The difference in stacking demonstrates the subtle role of weak non-covalent interlayer interactions and unit cell polarity in affecting the crystal architecture. [ABSTRACT FROM AUTHOR]

It remains a great challenge to achieve polar order in organic molecular crystals because anti‐parallel alignment of side‐by‐side molecules is intrinsically preferred. We have addressed this problem with a rational design that focuses on the polar stacking of parallel beloamphiphile monolayers (PBAMs) with strong lateral quadrupole‐quadrupole attractions. We employ arene‐arene interactions as lateral synthons. The first successes were achieved with unsymmetrical donor (X), acceptor (Y) substituted acetophenone azines which form polar PBAMs with double T‐contacts between the azines. Near‐perfect alignment was achieved with the methoxy series of (MeO, Y)‐azines with Y=Cl, Br, I. Here, we report on the synthesis, the characterization (GC/MS, 1H NMR, 13C NMR, FTIR), the crystallization, and the single‐crystal X‐ray analyses of the phenoxy series of (PhO, Y)‐acetophenone azines with Y=F, Cl, Br, I. Properties of (RO, Y) azines were computed at the APFD/6‐311G* level and are discussed with reference to p‐nitroaniline (PNA). This (PhO, Y) series embodies an improved PBAM design based on triple T‐contacts which is shown to facilitate faster crystallization and to produce larger crystals. Perfect polar‐alignment has been achieved for the phenoxy series of (PhO, Y)‐azines with Y=Cl, Br, I and the (PhO, F)‐azine also features near‐perfect dipole alignment. [ABSTRACT FROM AUTHOR]

Insecticidal non-proteinogenic amino acid S-(2-carboxyethyl)-L-cysteine (β-CEC) and its assumed metabolite, S-(2-carboxyethyl)-l-cysteine sulfoxide (β-CECO), are present abundantly in a number of plants of the legume family. In humans, these amino acids may occur as a result of exposure to environmental acrylonitrile or acrylamide, and due to consumption of the legumes. The β-CEC molecule is a homolog of S-carboxymethyl-l-cysteine (carbocisteine, CMC), a clinically employed antioxidant and mucolytic drug. We report here detailed structural data for β-CEC and β-CECO, as well as results of in vitro studies evaluating cytotoxicity and the protective potential of the amino acids in renal tubular epithelial cells (RTECs) equipped with reporters for activity of seven stress-responsive transcription factors. In RTECs, β-CEC and the sulfoxide were not acutely cytotoxic, but activated the antioxidant Nrf2 pathway. β-CEC, but not the sulfoxide, induced the amino acid stress signaling, which could be moderated by cysteine, methionine, histidine, and tryptophan. β-CEC enhanced the cytotoxic effects of arsenic, cadmium, lead, and mercury, but inhibited the cytotoxic stress induced by cisplatin, oxaliplatin, and CuO nanoparticles and acted as an antioxidant in a copper-dependent oxidative DNA degradation assay. In these experiments, the structure and activities of β-CEC closely resembled those of CMC. Our data suggest that β-CEC may act as a mild activator of the cytoprotective pathways and as a protector from platinum drugs and environmental copper cytotoxicity. [ABSTRACT FROM AUTHOR]

N‐alkylation of 5‐hydroxynicotinic acid esters with electrophiles containing diene functionality produces salts that undergo intramolecular (4+3) cycloaddition reactions upon heating in the presence of base. Initial studies used a three‐carbon tether to join the pyridinium ion and diene, revealing some aspects of the inherent selectivity of the reaction with such substrates. Much more challenging was the synthesis of related species possessing only a two‐carbon tether. Nevertheless, the cycloaddition of such compounds was successful, leading directly to the ABC ring system of the alkaloid daphnicyclidin A. [ABSTRACT FROM AUTHOR]

Enriched tungsten disulfide (186WS2) was evaluated at increasing proton beam currents (20–50 μA) and times (up to 4 h) on a GE PETtrace cyclotron for production of high specific activity (HSA) 186Re. The HSA 186Re was separated from the irradiated target as [186Re][ReO4]– by a liquid–liquid extraction method and radiolabeled with a new N2S2 ligand (222-MAMA-N-ethylpropionate). The enriched 186W was recovered from the extraction process, analyzed for purity and enrichment, and converted back to the disulfide (186WS2). The results demonstrate that the 186WS2 is an easily pressed target material that can withstand relatively high currents and can be readily recovered and recycled. The 186Re produced was isolated in high specific activity and readily formed the radiotracers [186Re][ReO(222-MAMA-N-ethylpropionate)] and [186Re][Re(CO)3(OH2)3] +. [ABSTRACT FROM AUTHOR]

CH8N2O3S, monoclinic, P21/c (no. 14), a = 9.7583 (16) Å, b = 5.4033 (9) Å, c = 10.4729 (17) Å, β = 110.483 (4)°, V = 517.29 (15) Å3, Z = 1, Rgt(F) = 0.0225, wRref(F2) = 0.0649, T = 150 K. [ABSTRACT FROM AUTHOR]

The first structural examples of complexes with uranium–germanium bonds are presented, namely, bis­[3,5-bis­(tri­fluoro­meth­yl)phenyl-2κC¹](hydrido-2κH)(iodido-1κI)bis­[1,1(η5)-penta­methyl­cyclo­penta­dien­yl]germaniumuranium(Ge—U), [GeU(C10H15)2(C8H3F6)2HI], and bis­[3,5-bis­(tri­fluoro­meth­yl)phenyl-2κC¹](fluorido-1κI)(hydrido-2κH)bis­[1,1(η5)-penta­methyl­cyclo­penta­dien­yl]germaniumuranium(Ge—U), [GeU(C10H15)2(C8H3F6)2FH]. The two complexes both have a long U—Ge bond [distances of 3.0428 (7) and 3.0524 (7) Å]. [ABSTRACT FROM AUTHOR]

The coordination of tBuNC and CO with the diarsenido complexes (C5Me5)2An(η2‐As2Mes2), An=Th, U, has been investigated. For the first time, a comparison between isostructural complexes of ThIV and UIV has been possible with CO; density functional calculations indicated an appreciable amount of π backbonding that originates from charge transfer from an actinide‐arsenic sigma bond. The calculated CO stretching frequencies in the ThIV and UIV diarsenido complexes are consistent with the experimental measurements, both show large shifts to lower frequency. We demonstrate that the π backbonding is crucial to explaining the red shifts of CO frequency upon AnIV complex formation. Interestingly, this interaction essentially correlates to the parallel orientation of π*(C−O) orbitals relative to the An−As bond. [ABSTRACT FROM AUTHOR]

An unusually large and structurally complex charge-neutral polynuclear cluster, hexa-μ2-azido-di-μ3-chlorido-hexa-μ2-hydroxido-di-μ3-oxido-hexakis(pentamethylcyclopentadienyl)hexathorium–diethyl ether–tetrahydrofuran (1/0.56/ 1.44), [Th3(C10H15)6Cl3(N3)6(OH)6O2]0.56C4H10O1.44C4H8O or [Th3(Cp*)3- (O)(OH)3]2Cl2(N3)60.56C4H10O1.44C4H8O (Cp* = [pentamethylcyclopentadienyl]), has been crystallized as a mixed tetrahydrofuran/diethyl ether solvate and structurally characterized. The molecule contains a number of unusual features, the most notable being a finite yet exceptionally long cyclic metal-azido chain. These rare features are the consequence of both sterically protecting Cp* ligands and highly bridging oxide and hydroxide ligands in the same system and illustrate the interesting new possibilities that can arise from combining organometallic and solvothermal f-block element chemistry. [ABSTRACT FROM AUTHOR]

Access to lanthanide acetate coordination compounds is challenged by the tendency of lanthanides to coordinate water and the plethora of acetate coordination modes. A straightforward, reproducible synthetic procedure by treating lanthanide chloride hydrates with defined ratios of the ionic liquid (IL) 1‐ethyl‐3‐methylimidazolium acetate ([C2mim][OAc]) has been developed. This reaction pathway leads to two isostructural crystalline anhydrous coordination complexes, the polymeric [C2mim]n[{Ln2(OAc)7}n] and the dimeric [C2mim]2[Ln2(OAc)8], based on the ion size and the ratio of IL used. A reaction with an IL : Ln‐salt ratio of 5 : 1, where Ln=Nd, Sm, and Gd, led exclusively to the polymer, whilst for the heaviest lanthanides (Dy−Lu) the dimer was observed. Reaction with Eu and Tb resulted in a mixture of both polymeric and dimeric forms. When the amount of IL and/or the size of the cation was increased, the reaction led to only the dimeric compound for all the lanthanide series. Crystallographic analyses of the resulting salts revealed three different types of metal‐acetate coordination modes where η2μκ2 is the most represented in both structure types. [ABSTRACT FROM AUTHOR]