Manipulation of the Thermochromic Transition Temperature in a Classic Metal-Organic Complex by Selective Anion Doping.

The origin of thermochromism displayed by the hybrid material [Ni(dieten)2](BF4)2 (dieten = N,N-diethylethylenediamine) is explored by anion substitution of the tetrafluoroborate anions (BF4-) with varying percentages (0-25%) of bromide (Br-). Differential scanning calorimetry and variable-temperature diffuse reflectance spectroscopy indicate that the yellow-orange to orange-red thermochromic transition inherent to undoped [Ni(dieten)2](BF4)2 shifts from 100 to 90 °C as the doping concentration increases from 0 to 25%. Similarly, a 15 nm line broadening of the Kubelka-Munk transformed diffuse reflectance signal (proportional to the absorbance of the complex) and a broadening of the endothermic transition are observed with increasing Br- doping. The structure of the undoped [Ni(dieten)2](BF4)2, determined by single-crystal X-ray diffraction, is presented, and powder X-ray diffraction was used to confirm that the crystal structure and crystallinity of each doped sample remains unchanged from the BF4- phase. We provide evidence for an underlying mechanism of thermochromism that is linked to hydrogen bonding within the crystal structure and which can be manipulated via targeted modulation of lattice anions. The mechanism proposed here is likely applicable to other materials within the family of dieten complexes ([M(dieten)2](X)2, where M = Ni2+, Cu2+ and X = BF4-, ClO4-, NO3-).

An Americium-Containing Metal-Organic Framework: A Platform for Studying Transplutonium Elements.

The synthesis, structure, and spectroscopic characterization of the first transplutonium metal-organic framework (MOF) is described. The preparation and structure of Am-GWMOF-6, [Am2 (C6 H8 O4 )3 (H2 O)2 ][(C10 H8 N2 )], is analogous to that of the isostructural trivalent lanthanide-only containing material GWMOF-6. The presented MOF architecture is used as a platform to probe Am3+ coordination chemistry and guest-enhanced luminescent emission, whereas the framework itself provides a means to monitor the effects of self-irradiation upon crystallinity over time. Presented here is a discussion of these properties and the opportunities that MOFs provide in the structural and spectroscopic study of actinides.

Novel Heterometallic Uranyl-Transition Metal Materials: Structure, Topology, and Solid State Photoluminescence Properties.

Six new uranyl hybrid materials have been synthesized solvothermally utilizing the ligands 2,2'-bipyridine-3,3'-dicarboxylic acid (H2L) and 2,2':6',2''-terpyridine (TPY). The six compounds are classified as either molecular complexes (I0O0 connectivity), [(UO2)(L)(TPY)]·H2O (1), [Ni(TPY)2][(UO2)(L)2]·3H2O (2), and [Cu(TPY)2][(UO2)(L)2]·3H2O (3), or 3D metal-organic frameworks (MOFs, I0O3 connectivity), [Cu2(UO2)2(OH)(C2H3O2)(L)3(TPY)2]·6H2O (4), [Zn2(UO2)2(OH)(NO3)(C2H3O2)(L)3(TPY)2]·4H2O (5), and Na[Ni(UO2)3(OH)(O)(L)3]·9H2O (6). A discussion of the influence of transition metal incorporation, chelating effects of the ligand, and synthesis conditions on the formation of uranyl materials is presented. The structure of compound 6 is of particular note due to large channel-like voids with a diameter of approximately 19.6 Å. A topological analysis of 6 reveals a new topology with a 9-nodal 3,3,3,3,3,3,3,4,5-connected network, designated geg1 hereafter. Further, solid state photoluminescence experiments show emission and lifetimes values consistent with related uranyl compounds.

A Thorium Metal-Organic Framework with Outstanding Thermal and Chemical Stability.

A new thorium metal-organic framework (MOF), Th(OBA)2 , where OBA is 4,4'-oxybis(benzoic) acid, has been synthesized hydrothermally in the presence of a range of nitrogen-donor coordination modulators. This Th-MOF, described herein as GWMOF-13, has been characterized by single-crystal and powder X-ray diffraction, as well as through a range of techniques including gas sorption, thermogravimetric analysis (TGA), solid-state UV/Vis and luminescence spectroscopy. Single-crystal X-ray diffraction analysis of GWMOF-13 reveals an interesting, high symmetry (cubic Ia 3 ‾ d) structure, which yields a novel srs-a topology. Most notably, TGA analysis of GWMOF-13 reveals framework stability to 525 °C, matching the thermal stability benchmarks of the UiO-66 series MOFs and zeolitic imidazolate frameworks (ZIFs), and setting a new standard for thermal stability in f-block based MOFs.

How to Bend the Uranyl Cation via Crystal Engineering.

Bending the linear uranyl (UO22+) cation represents both a significant challenge and opportunity within the field of actinide hybrid materials. As part of related efforts to engage the nominally terminal oxo atoms of uranyl cation in noncovalent interactions, we synthesized a new uranyl complex, [UO2(C12H8N2)2(C7H2Cl3O2)2]·2H2O (complex 2), that featured both deviations from equatorial planarity and uranyl linearity from simple hydrothermal conditions. Based on this complex, we developed an approach to probe the nature and origin of uranyl bending within a family of hybrid materials, which was done via the synthesis of complexes 1-3 that display significant deviations from equatorial planarity and uranyl linearity (O-U-O bond angles between 162° and 164°) featuring 2,4,6-trihalobenzoic acid ligands (where Hal = F, Cl, and Br) and 1,10-phenanthroline, along with nine additional "nonbent" hybrid materials that either coformed with the "bent" complexes (4-6) or were prepared as part of complementary efforts to understand the mechanism(s) of uranyl bending (7-12). Complexes were characterized via single crystal X-ray diffraction and Raman, infrared (IR), and luminescence spectroscopy, as well as via quantum chemical calculations and density-based quantum theory of atoms in molecules (QTAIM) analysis. Looking comprehensively, these results are compared with the small library of bent uranyl complexes in the literature, and herein we computationally demonstrate the origin of uranyl bending and delineate the energetics behind this process.

Two novel bimetallic transition metal-uranyl one-dimensional coordination polymers with manganese(II) and cobalt(II) incorporating bridging diglycolate (2,2'-oxydiacetate) ligands.

The crystal structures of two new bimetallic uranyl-transition metal compounds with diglycolic acid [or 2-(carboxymethoxy)acetic acid] have been hydrothermally synthesized and structurally characterized via single-crystal X-ray diffraction. The compounds, namely catena-poly[[[tetraaquamanganese(II)]-µ-2,2'-oxydiacetato-[dioxidouranium(VI)]-µ-2,2'-oxydiacetato] dihydrate], {[MnU(C4H4O5)2O2(H2O)4]·2H2O}n, and catena-poly[[[tetraaquacobalt(II)]-µ-2,2'-oxydiacetato-[dioxidouranium(VI)]-µ-2,2'-oxydiacetato] dihydrate], {[CoU(C4H4O5)2O2(H2O)4]·2H2O}n, both crystallize in the triclinic space group P-1. These compounds form one-dimensional chains via alternating uranyl and transition metal building units. The chains then assemble into three-dimensional supramolecular networks through several hydrogen bonds between water molecules and diglycolate ligands. Luminescence measurements were conducted and no uranyl emission was observed in either compound.

Identifying genes in Fusarium verticillioides through forward and reverse genetics.

The increasing availability of sequenced genomes for plant pathogenic fungi has revolutionized molecular plant pathology in recent years. However, the genetic regulatory networks underlying many important components of pathogenesis remain poorly defined. Although the protocols outlined in this chapter can be utilized to identify genes regulating a wide range of biological processes in many filamentous fungi, we focus on describing how to identify genes through forward and reverse genetics, using the plant pathogenic fungus Fusarium verticillioides as a model for the protocol. Specifically, this chapter explains how to create a collection of insertional mutants via Restriction Enzyme Mediated Integration (REMI) and how to screen mutants with a high-throughput method to visualize defects in amylolysis. Next, techniques are described to define the genomic lesions in REMI mutants with genome-walker PCR in order to identify candidate genes. Finally, protocols are presented describing a reverse-genetic approach to disrupt candidate genes in the wild-type strain with a split-marker strategy to confirm the phenotype observed in the REMI mutant.

Nurse leadership competencies for the 21st century.

Nurse managers and administrators must understand the competencies necessary to be successful in a changing health care environment. Critical leadership competencies have a significant impact on patient outcomes, cultivating and environment for continuous learning, interdepartmental and intradepartmental customer relationships within and across agencies, use of resources, strategic planning, and compliance with regulatory requirements. This article presents a review of literature and expert thought related to critical administrative and leadership competencies. The skills and competencies the experts discuss are universal, suggesting that the work venue is irrelevant to nurse leadership behavior, which translates across settings.

Measuring competencies: development of the administrator competency survey.

Competency assessments is critical for nurse managers who must move between and among health care settings. This article reports development of a survey tool to measure administrative competencies to facilitate career movement based on competencies versus traditional structure of education and experience. The study was designed to determine specific competencies that were deductively derived and considered essential for successful leadership in the year 2000. These included eight domains: quality improvement, shared visions, global approach, serving community, mastering change, team learning, managing customer relationships, and managing a diverse workforce. The tool was used to measure nurse administrator competency in a select group. Results identified expertise and targeted priorities for training and improvement.

Congenital hypertrophy of an intrinsic muscle of the foot.

Congenital hypertrophic muscles of the foot are rare and a search of the literature revealed only a few select cases on the subject. However, a case did present itself at Saint Michael's Medical Center involving a congenitally hypertrophic abductor digiti minimi muscle of the right foot. Surgical exploration also revealed slight abnormalities of the third and fourth plantar interosseous muscles. These muscles, however, were left intact because they were not symptomatic. There were no other hypertrophic muscles noticed on this foot and none in the opposite foot. Excision of the entire hypertrophic muscle eventually provided complete relief and allowed the patient to wear normal foot gear. This manuscript describes a case presentation of a single congenitally hypertrophic muscle with reference to its clinical evaluation and subsequent treatment.