Enantiomerically Pure Tetravalent Neptunium Amidinates: Synthesis and Characterization

The synthesis of a tetravalent neptunium amidinate [NpCl((S )‐PEBA)$_{3}$] (1 ) ((S )‐PEBA=(S ,S )‐N ,N′‐bis‐(1‐phenylethyl)‐benzamidinate) is reported. This complex represents the first structurally characterized enantiopure transuranic compound. Reactivity studies with halide/pseudohalides yielding [NpX((S )‐PEBA)$_{3}$] (X=F (2 ), Br (3 ), N3 (4 )) have shown that the chirality‐at‐metal is preserved for all compounds in the solid state. Furthermore, they represent an unprecedented example of a structurally characterized metal–organic Np complex featuring a Np−Br (3 ) bond. In addition, 4 is the only reported tetravalent transuranic azide. All compounds were additionally characterized in solution using para‐magnetic NMR spectroscopy showing an expected C$_{3}$‐symmetry at low temperatures

Neptunyl(VI) centred visible LMCT emission directly observable in the presence of uranyl(VI)

Room temperature detection of neptunyl(VI) LMCT emission in a coordination compound and in the presence of uranyl(VI) is reported for the first time. Differences in the excitation profiles of the complexes enable spectral editing so either exclusively neptunyl(VI) or uranyl(VI) emission is observed or a sum of the two

Comparative NMR Study of nPrBTP and iPrBTP

Bistriazinyl-pyridine type ligands are important extracting agents for separating trivalent actinide ions from trivalent lanthanides. The alkyl substituents on the lateral triazine rings have a significant effect on the stability of the ligand against hydrolysis and radiolysis. Furthermore they influence solubility, extraction behaviour and selectivity. TRLFS and extraction studies suggest differences in complexation and extraction behaviour of BTP ligands bearing iso-propyl or n-propyl substituents, respectively. As NMR studies allow insight into the metal-ligand bonding, we conducted NMR studies on a range of 15N-labelled nPrBTP and iPrBTP Ln(III) and Am(III) complexes. Our results show that no strong change in the metal-ligand bonding occurs, thus excluding electronic reasons for differences in complexation behaviour, extraction kinetics and selectivity. This supports mechanistic reasons for the observed differences

Winter 2015

Volume 2, Issue 1 Winter 2015Volumn 2, Issue 1 of the Journal of Teaching Effectiveness and student AcievementAngelo State University College of EducationInvestigating a Model of Mentoring for Effective Teaching Dr. Lori Bird and Dr. Peter Hudson…….p11 Early Career Teacher Attrition: Searching for Answers in Preservice Preparation Dr. Gloria Graham Flynn………p22 A Perceptual Assessment of Non-Traditional STEM Teacher Candidates: A University Partnership for Transition to Teaching Dr. Gail Hughes, Dr. Alicia Cotabish, Dr. Carolyn Williams, and Dr. Donna Wake…..p32 Baby It’s Cold Outside: Perspectives on Teacher Retention and Student Achievement in Artic Schools Dr. Ute Kaden………p45 Transformations to Serve English Learners: A Call for Innovative Partnerships in Educator Preparation Dr. Joan Lachance………p56 Successes and Struggles of Teaching: Perspectives of Beginning, Mid-Career, and Veteran Teachers Dr. Alyson Lavigne and Dr. Amanda Bozack………p68 Teacher Inquiry: A Foundation for Mentoring Teachers During Induction and Throughout Their Career Dr. Michele Marable, Dr. Kristin Kurtsworth--‐Keen, Dr. Kelly Harper, and Dr. Karen Dutt-Doner…….p81 Perceptions of Transformational Leadership Behavior by Secondary Principals and Teachers in Diverse and Non-Diverse Schools Dr. Fernando Valle and Dr. Gionet Cooper…..p9

Triply bonded pancake π-dimers stabilized by tetravalent actinides

Aromatic π-stacking is a weakly attractive, noncovalent interaction often found in biological macromolecules and synthetic supramolecular chemistry. The weak nondirectional nature of π-stacking can present challenges in the design of materials owing to their weak, nondirectional nature. However, when aromatic π-systems contain an unpaired electron, stronger attraction involving face-to-face π-orbital overlap is possible, resulting in covalent so-called “pancake” bonds. Two-electron, multicenter single pancake bonds are well known, whereas four-electron double pancake bonds are rare. Higher-order pancake bonds have been predicted, but experimental systems are unknown. Here, we show that six-electron triple pancake bonds can be synthesized by a 3-fold reduction of hexaazatrinaphthylene (HAN) and subsequent stacking of the [HAN]3– triradicals. Our analysis reveals a multicenter covalent triple pancake bond consisting of a σ-orbital and two equivalent π-orbitals. An electrostatic stabilizing role is established for the tetravalent thorium and uranium ions in these systems. We also show that the electronic absorption spectrum of the triple pancake bonds closely matches computational predictions, providing experimental verification of these unique interactions. The discovery of conductivity in thin films of triply bonded π-dimers presents new opportunities for the discovery of single-component molecular conductors and other spin-based molecular materials

Acute mountain sickness.

Acute mountain sickness (AMS) is a clinical syndrome occurring in otherwise healthy normal individuals who ascend rapidly to high altitude. Symptoms develop over a period ofa few hours or days. The usual symptoms include headache, anorexia, nausea, vomiting, lethargy, unsteadiness of gait, undue dyspnoea on moderate exertion and interrupted sleep. AMS is unrelated to physical fitness, sex or age except that young children over two years of age are unduly susceptible. One of the striking features ofAMS is the wide variation in individual susceptibility which is to some extent consistent. Some subjects never experience symptoms at any altitude while others have repeated attacks on ascending to quite modest altitudes. Rapid ascent to altitudes of 2500 to 3000m will produce symptoms in some subjects while after ascent over 23 days to 5000m most subjects will be affected, some to a marked degree. In general, the more rapid the ascent, the higher the altitude reached and the greater the physical exertion involved, the more severe AMS will be. Ifthe subjects stay at the altitude reached there is a tendency for acclimatization to occur and symptoms to remit over 1-7 days

Coordination of Trivalent Lanthanum and Cerium, and Tetravalent Cerium and Actinides (An = Th(IV), U(IV), Np(IV)) by a 4-Phosphoryl 1H-Pyrazol-5-olate Ligand in Solution and the Solid State

This dataset is a subset of the complete data used in the original publication. It contains NMR and XAS data and there simulation. Based on this original data, conclusions are drawn in the linked publication. For the full data, please refer to the corresponding author of the full publication