Coordination Chemistry and Photoluminescence of Sm(II) Dibenzo-24-crown-8 Complexes.

Three Sm(II) dibenzo-24-crown-8 (db24c8) complexes were synthesized in anhydrous, air-free conditions via the reaction of SmI with db24c8 and tetrabutylammonium tetraphenylborate ([TBA][BPh]; where needed) in acetonitrile (CHCN), dimethoxyethane (DME), and tetrahydrofuran (THF) to yield [Sm(db24c8)(CHCN)][BPh][I]·CHCN, [Sm(db24c8)(DME)]I, and [Sm(db24c8)(THF)]I, respectively. In each case, a 10-coordinate, staggered dodecahedral (2:6:2) environment is formed around the Sm center that is completed by either two solvent molecules (CHCN or THF) or one bidentate solvent molecule (DME). Inner-sphere solvent molecules can be excluded by reacting SmI with db24c8 in 1:3 THF:toluene to yield Sm(db24c8)I.

Covalent inhibitors of the RAS binding domain of PI3Kα impair tumor growth driven by RAS and HER2.

Genetic disruption of the RAS binding domain (RBD) of PI 3-kinase (PI3K) prevents the growth of mutant RAS driven tumors in mice and does not impact PI3K's role in insulin mediated control of glucose homeostasis. Selectively blocking the RAS-PI3K interaction may represent an attractive strategy for treating RAS-dependent cancers as it would avoid the toxicity associated with inhibitors of PI3K lipid kinase activity such as alpelisib. Here we report compounds that bind covalently to cysteine 242 in the RBD of PI3K p110α and block the ability of RAS to activate PI3K activity.

Crystal structure of [Ni(OH)]Cl·(18-crown-6)·2HO.

The crystal structure of the title compound, hexa-aqua-nickel(II) dichloride-1,4,7,10,13,16-hexa-oxa-cyclo-octa-deca-ne-water (1/2/2), [Ni(HO)]Cl·2CHO·2HO, is reported. The asymmetric unit contains half of the Ni(OH) moiety with a formula of CHClNiO at 105 K and triclinic (1) symmetry. The [Ni(OH)] cation has close to ideal octa-hedral geometry with O-Ni-O bond angles that are within 3° of idealized values.

Deviation between the Structural Chemistry of Barium and Radium Halides: Synthesis and Characterization of RaX·HO and RaX·2HO (X = Cl and Br).

To develop the structural chemistry of radium, the halide compounds RaX·HO and RaX·2HO (X = Cl and Br) have been synthesized and characterized and serve as benchmarks for comparisons with more complex compounds in the future. In contrast with historic reports on the structural chemistry of radium, the Ra chlorides differ from their Ba analogues. For MCl·HO (M = Ba, Ra), the variance between the metal coordination environments manifests as a small, local distortion that becomes more apparent in the extended structure.

Comparison of Americium(III) and Neodymium(III) Monothiophosphate Complexes.

Mixed-donor ligands, such as those containing a combination of O/N or O/S, have been studied extensively for the selective extraction of trivalent actinides, especially Am and Cm, from lanthanides during the recycling of used nuclear fuel. Oxygen/sulfur donor ligand combinations also result from the hydrolytic and/or radiolytic degradation of dithiophosphates, such as the Cyanex class of extractants, which are initially converted to monothiophosphates. To understand potential differences between the binding of such degraded ligands to Nd and Am, the monothiophosphate complexes [M(OPS(OEt))(HO)] (M = Nd, Am) were prepared and characterized by single-crystal X-ray diffraction and optical spectroscopy and studied as a function of pressure up to ca.