Synthesis of bismuthanyl-substituted monomeric triel hydrides.

The syntheses and characterizations of the first bismuthanylborane monomers stabilized only by a donor in D·BHBi(SiMe) (D = DMAP 1a, IDipp 1b, IMe1c; DMAP = 4-dimethylaminopyridine, IDipp = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene, IMe = 1,3,4,5-tetramethylimidazol-2-ylidene) are presented. All compounds were synthesized by salt metathesis reactions between D·BHI and KBi(SiMe)(THF) and represent some of the extremely rare compounds featuring a 2c-2e B-Bi bond in a molecular compound. The products display high sensitivity towards air and light and slowly decompose in solution even at -80 °C.

Investigation of 252Cf sources with a Ge gamma-ray detector.

This study investigated the feasibility of combining high-resolution gamma-ray spectroscopy with the simulation capabilities of the Nucleonica Nuclear Science Portal with the aim to determine the properties of Cf sources. In this contribution, we present the results for a 20-month-old and a 49-year-old Cf source. In particular, the question arises whether the neutron emission rate can be determined using gamma-ray spectroscopy.

Identifying underlying individuality across running, walking, and handwriting patterns with conditional cycle-consistent generative adversarial networks.

In recent years, the analysis of movement patterns has increasingly focused on the individuality of movements. After long speculations about weak individuality, strong individuality is now accepted, and the first situation-dependent fine structures within it are already identified. Methodologically, however, only signals of the same movements have been compared so far.

Effectiveness of Psychomotor Therapy among Children with Graphomotor Impairment with and without DCD-Diagnosis.

In Switzerland, psychomotor therapy (PMT) is a standard treatment for children with graphomotor impairments, but scientific evidence of its effectiveness is rare. To investigate the effectiveness of PMT, we conducted a randomised field trial (RFT). The sample consisted of 121 first and second graders with graphomotor impairments, some of whom met the criteria of developmental coordination disorder, while the remaining suffered from developmental dysgraphia.

Handwriting kinematics during learning to write with the dominant left hand in converted left-handers.

Converting left-handers to their non-dominant right hand was previously widespread, particularly for handwriting. The present study aimed to explore the extent to which adult, converted left-handers can learn writing with their dominant left hand during a 2-year training program. Eleven converted left-handers participated in the training.

Three- and Five-Membered Anionic Chains of Pnictogenylboranes.

An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H E'-BH -NMe (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2= Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H E'-BH -EH Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H E'-BH -EPh ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.

Coordination of Pnictogenylboranes Towards Tl(I) Salts and a Tl- Mediated P-P Coupling.

The coordination chemistry of only Lewis-base (LB)-stabilized pnictogenylboranes EH BH ⋅NMe (E=P, As) towards Tl(I) salts has been studied. The reaction of Tl[BAr ] (BAr =[B(3,5-C H Cl ) ] ) with the corresponding pnictogenylborane results in the formation of [Tl(EH BH ⋅NMe )][BAr ] (1 a: E=P; 1 b: E=As). Whereas the Tl ion in 1 a/b is monocoordinated, the exchange of the weakly coordinating anion (WCA) in the Tl(I) salt leads to the formation of a trigonal pyramidal coordination mode at the Tl atom by coordination of three equivalents of EH BH  ⋅ NMe in [Tl(EH BH  ⋅ NMe ) ][WCA] (2 a: E=P, WCA=TEF ; 2 b: E=As, WCA=TEF) (TEF=[Al{OC(CF ) } ] , TEF =[Al{(OC(CF ) (CCl )} ] ).

Dystonic Golfer's cramp: Pilot study of propranolol and looking at the hole.

Introduction: There is limited data in the scientific literature using quantitative methods to assess response of golfer's cramp to intervention. The objective of this pilot study was to use quantitative measures to study the effect of propranolol and looking at the hole when putting.

Methods: 14 golfers completed 50 10' putts (10 each x 5 conditions): two-handed looking at the ball, right hand only looking at the ball, two-handed looking at the hole, then following a single 10 mg oral dose of propranolol two-handed and right hand only putts looking at the ball.

The Yips: Methods to Identify Golfers with a Dystonic Etiology/Golfer's Cramp.

Purpose: To determine whether quantitative methods could separate golfers with a possible dystonic cause of the "yips" from those that appear to be nondystonic.

Methods: Twenty-seven golfers completed 10 two-handed and 10 right hand-only putts. Surface EMG assessed forearm muscle co-contraction and motion detectors monitored wrist and putter movements.

Depolymerization of Poly(phosphinoboranes): From Polymers to Lewis Base Stabilized Monomers.

We report on depolymerization reactions of poly(phosphinoboranes). The cleavage of the polymers [H PBH ] (2 a), [tBuHPBH ] (2 c), [PhHPBH ] (2 e) and the oligomer [Ph PBH ] (2 b), with strong Lewis bases (LBs), in particular with NHCs, leads to the corresponding monomeric phosphanylboranes R R PBH LB. It is observed that the depolymerization depends on the strength and stability of the LBs as well as on the substitution pattern of the poly(phosphinoboranes).

Superradiance from Two Dimensional Brick-Wall Aggregates of Dye Molecules: The Role of Size and Shape for the Temperature Dependence.

Aggregates of interacting molecules can exhibit electronically excited states that are coherently delocalized over many molecules. This can lead to a strong enhancement of the fluorescence decay rate which is referred to as superradiance (SR). To date, the temperature dependence of SR is described by a 1/T law.

A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions.

We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it.

A Convenient Route to Mixed Pnictogenylboranes.

We report on the synthesis and characterization of mixed pnictogenylboranes. The substitution of the Lewis base SMe in (OC) W-PH BH -SMe (2) by different pnictogenylboranes ER BH -LB (E=P, As, Sb) leads to the Lewis acid/base stabilized butane analogue (OC) W-PH BH ER BH -LB (3 a, b: E=P; R=H, SiMe ; LB=NMe ; 4 a, b: E=As; R=H, SiMe ; LB=NMe ; 5: E=Sb; R=SiMe ; LB=NHC ). All of these compounds were characterized by single-crystal X-ray structure analysis, mass spectrometry, NMR, and IR spectroscopy.

Cationic Chains of Parent Arsanylboranes and Substituted Phosphanylboranes.

The substituted monomeric phosphanylboranes Ph P-BH ⋅NMe (1) and tBuHP-BH ⋅NMe (2) have been used for the synthesis of cationic chain compounds built up by R P-BH units. With a simple synthesis route, the highly stable cations [Me N⋅H B-PR R -BH ⋅NMe ] (1 a, 2 a) and [Me N⋅H B-PR R -BH -PR R -BH ⋅NMe ] (1 b, 2 b) (R =R =Ph; R =H, R =tBu) are obtained as iodide (I ) salts. The reaction of H As-BH ⋅NMe (3) with IBH ⋅SMe leads to [Me N⋅H B-AsH -BH -AsH -BH ⋅NMe ][I] (3 a), the longest so far known arsanylborane chain.

Oxidation of Substituted Phosphanylboranes with Chalcogens.

The elemental chalcogens sulfur, selenium, tellurium and bis(trimethylsilyl)peroxide as an oxygen source are applied for the oxidation of the phosphanylboranes Ph P-BH ⋅NMe (1) and tBuHP-BH ⋅NMe (2). The corresponding monooxidation products Ph P(X)-BH ⋅NMe (X=O-Te, 3 a-d) and tBuHP(X)-BH ⋅NMe (X=O-Te, 4 a-d) were obtained in good yields and comprehensively characterized by single crystal X-ray structure analysis, NMR, IR spectroscopy and mass spectrometry. The first oxidation step proceeds very selectively for all chalcogenides.

Anionic Chains of Parent Pnictogenylboranes.

We report on the synthesis and structural characterization of unprecedented anionic parent compounds of mixed Group 13/15 elements. The reactions of the pnictogenylboranes H E-BH ⋅NMe (1 a=P, 1 b=As) with phosphorus and arsenic centered nucleophiles of the type [EH ] (E=P, As) lead to the formation of compounds of the type [H E-BH -E'H ] (2: E=E'=P; 3: E=E'=As; 4: E=P, E'=As) containing anionic pnictogen-boron chain-like units. Furthermore, a longer 5-membered chain species [H As-BH -PH -BH -AsH ] (5) and a cyclic compound [NHC -H B-PH -BH -NHC ] [P B H ] (6) containing a n-butylcyclohexane-like anion were obtained.

Sorption and redox speciation of plutonium at the illite surface under highly saline conditions.

Natural groundwater may contain high salt concentrations, such as those occurring at several potential deep geological nuclear waste repository sites. Actinide sorption to clays (e.g.

Sorption and Redox Speciation of Plutonium at the Illite Surface.

The geochemical behavior of Pu strongly depends on its redox speciation. In this study, we investigated Pu sorption onto Na-illite, a relevant component of potential host rocks for high-level nuclear waste repositories, under anaerobic conditions. When contacting Pu (85% Pu(IV), 11% Pu(V), and 4% Pu(III); 8 × 10(-11) < [Pu]tot/M < 10(-8)) with illite in 0.

First structural characterization of Pa(iv) in aqueous solution and quantum chemical investigations of the tetravalent actinides up to Bk(IV): the evidence of a curium break.

More than a century after its discovery the structure of the Pa(4+) ion in acidic aqueous solution has been investigated for the first time experimentally and by quantum chemistry. The combined results of EXAFS data and quantum chemically optimized structures suggest that the Pa(4+) aqua ion has an average of nine water molecules in its first hydration sphere at a mean Pa-O distance of 2.43 Å.

Metal-Free Addition/Head-to-Tail Polymerization of Transient Phosphinoboranes, RPH-BH2: A Route to Poly(alkylphosphinoboranes).

Mild thermolysis of Lewis base stabilized phosphinoborane monomers R(1)R(2)P-BH2⋅NMe3 (R(1),R(2)=H, Ph, or tBu/H) at room temperature to 100 °C provides a convenient new route to oligo- and polyphosphinoboranes [R(1)R(2)P-BH2]n. The polymerization appears to proceed via the addition/head-to-tail polymerization of short-lived free phosphinoborane monomers, R(1)R(2)P-BH2. This method offers access to high molar mass materials, as exemplified by poly(tert-butylphosphinoborane), that are currently inaccessible using other routes (e.

Isolation and Characterization of Lewis Base Stabilized Monomeric Parent Stibanylboranes.

The synthesis of the Lewis base stabilized monomeric parent compound of stibanylboranes, "H2 Sb-BH2 ", is reported. Through a salt metathesis route, the silyl-substituted compounds (Me3 Si)2 Sb-BH2 ⋅LB (LB=NMe3 , NHC(Me) ) were synthesized as representatives of derivatives with a Sb-B σ bond. Under very mild conditions, they could be transformed into the target compounds Me3 N⋅H2 B-HSb-BH2 ⋅NMe3 and H2 Sb-BH2 ⋅NHC(Me) , respectively.

Sensitive redox speciation of iron, neptunium, and plutonium by capillary electrophoresis hyphenated to inductively coupled plasma sector field mass spectrometry.

The long-term safety assessment for nuclear waste repositories requires a detailed understanding of actinide (geo)chemistry. Advanced analytical tools are required to gain insight into actinide speciation in a given system. The geochemical conditions in the vicinity of a nuclear repository control the redox state of radionuclides, which in turn has a strong impact on their mobility.

Np(v) complexation with propionate in 0.5-4 M NaCl solutions at 20-85 °C.

Low molecular weight organics (LMWO; e.g. acetate, propionate, lactate) can significantly impact the speciation and mobility of radionuclides in aqueous media.

Cationic chains of phosphanyl- and arsanylboranes.

Whilst catena-phosphorus cations have been intensively studied in the last years, mixed Group 13/15 element cationic chains have not yet been reported. Reaction of the pnictogenboranes H2EBH2⋅NMe3 (E=P, As) with monohalideboranes lead to the cationic chain compounds [Me3N⋅BH2EH2BH2⋅NMe3][X] (E=P, As; X=AlCl4 , I) and [Me3N⋅BH2PH2BH2PH2BH2⋅NMe3][X] (X=I, VCl4(thf)2), respectively. All of the compounds have been characterized by X-ray structure analysis, NMR spectroscopy, IR spectroscopy, and mass spectrometry.