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Two homologous series of pnictogen(III) dications, stabilized by 2,6‐bis(benzimidazole‐2‐yl)pyridine ligands have been prepared. Both series contain PnIII‐X moieties (Pn = P, As, Sb, Bi; X = Cl or Ph) and have been fully characterized using spectroscopic methods including X‐ray crystallography. The Lewis acidity of these compounds has also been probed by computational methods; the results suggest that the dictations are strong Lewis acids, with the PnCl2+ compounds being more acidic than the PnPh2+ compounds, and with Lewis acidity increasing from P to Bi, in both series. The PhP2+‐containing compound was also found to be a versatile PIII transfer reagent, leading to new synthetic routes for various PhP‐containing compounds. The redox chemistry of all compounds has also been probed using cyclic voltammetry and chemical reductions. In some cases the resulting PnI moieties could be trapped using diazabutadienes. [ABSTRACT FROM AUTHOR]

The activities of the EUROfusion consortium on the development of high quality nuclear data for fusion applications include evaluations of deuteron induced reactions and related data libraries for needs of the DEMO fusion power plant and IFMIF-DONES neutron-source nuclear analyses. Molybdenum is one of the major constituents of the reference stainless steels used in critical components of these projects. While the TENDL deuteron data library was the current reference used by EUROfusion, need of its further improvement has already been pointed out. The weak binding energy of the deuteron is responsible for the high complexity of its interaction with nuclei, involving also a variety of reactions initiated by the nucleons following the deuteron breakup. Their analysis completed that of the deuteron interactions with Mo and its stable isotopes, from elastic scattering to pre-equilibrium and compound–nucleus reactions, up to 50 MeV. A particular attention has been paid to the breakup, stripping, and pick-up direct interactions which amount to around half of the deuteron total–reaction cross section. The due account of most experimental data has validated the present approach, highlighted some prevalent features, and emphasized weak points and consequently the need for modeling/evaluation upgrade. [ABSTRACT FROM AUTHOR]

The 2 6 Mg (n , γ) 2 7 Mg reaction plays a crucial role in the process of nucleosynthesis in stars. It occurs primarily in massive stars during their late evolutionary stages or during explosive events like supernovae. This paper focuses on investigating discrepancies in the ANC values of the 2 6 Mg (n , γ) 2 7 Mg reaction by analyzing experimental angular distributions of 2 6 Mg (d , p) 2 7 Mg using the DWBA, ADWA and CDCC methods for both ground and first excited states. We then use a mirror nucleus procedure to extract information on the ANCs of the ground state 2 6 Si (p , γ) 2 7 P reaction. The Hauser–Feshbach formalism of the statistical Compound Nucleus (CN) model was applied in this study to perform a compound-nucleus analysis of the 2 6 Mg (d , p) 2 7 Mg reaction. The 2 6 Mg (d , p) 2 7 Mg reaction has almost fulfilled the condition of peripherality, which is necessary for understanding the magnitude of the direct reaction contribution. ANCs for the 2 7 Mg → 2 6 Mg + n virtual decay system were obtained. Moreover, according to charge symmetry of mirror nuclei, the square of proton ANC for a 2 7 P → 2 6 Si + p is determined and comparison between the values of the presented ANCs. [ABSTRACT FROM AUTHOR]

Inspired by the prevalent n + p cluster structure of deuterons, which appears at an excitation energy of 2.225 MeV, the recently measured angular distributions (ADs) for 1 5 N(d , d) 1 5 N and 1 5 N(d , p) 1 6 N systems at an energy of 15 MeV X. Y. Li et al., [Phys. Rev. C 106, (2022) 025807] are microscopically analyzed using the continuum discretized coupled channel (CDCC) method. The extracted U eff potential, considered as the coherent sum of cluster folding and dynamical polarization potentials, both derived from the CDCC computations, was then employed to investigate the 1 5 N(d , p) 1 6 N neutron transfer reaction leading to the (2−, 0.0 MeV), (0−, 0.12 MeV), (3−, 0.298 MeV), and (1−, 0.397 MeV) 1 6 N states. Since extracting reliable information on spectroscopic factors (SFs) is highly dependent on the interaction potential, the extracted U eff was employed to get such information. The investigation gives evidence for the applicability of the U eff in describing the elastic scattering and the neutron transfer ADs data. The extracted SFs for the 1 6 N states under consideration are consistent with those that have been reported before. [ABSTRACT FROM AUTHOR]

Helical-orbit solenoidal spectrometers, in which the target and detector are placed inside a uniform magnetic field, have been utilized for more than a decade to study nuclear reactions in inverse kinematics, induced by radioactive beams. Methods to improve the final-state energy resolution are presented, and the inclusion of an active gas target is proposed to improve the performance of the spectrometer. [ABSTRACT FROM AUTHOR]

An experimental protocol to achieve the Meerwein−Ponndorf−Verley (MPV) reduction of ketones under mildly basic conditions is reported. The transformation is tolerant of a range of ketone substrates, including O- and S-containing heterocycles, is scalable, and shows potential to be used as a platform to access enantioenriched products. These studies provide a general method for achieving the reduction of ketones under mildly basic conditions and offer an alternative protocol to more well-known Al-based MPV reduction conditions.

Doping enhances the activation of peroxymonosulfates (PMS) by metal-free carbon materials, addressing their inherent limitations in performance. In this study, experimental and theoretical calculations are combined to carry out the study of efficient activation of PMS for tetracycline degradation based on sulfur-doped g-C 3 N 4 (SCN) as a promising photocatalyst. Calculation of the energy band structure, electronic and optical properties by density-functional theory methods suggests that doping results in a smaller band gap, smaller bond populations, and work function, leading to a redistribution of charges and dipoles at the g-C 3 N 4 interface with a better ability to separate photogenerated h+/e− pairs. Meanwhile, the characterization and catalyst activity measurements indicate that doping improves the photocatalytic activity, which is in agreement with the theoretical calculations. In particular, the SCN synthesized at 1:1 ratio exhibited the best catalytic activity, and the degradation efficiency of TC within 2 h could reach 89.4 %. This study provides a highly effective metal-free carbon activator for the degradation of antibiotics from wastewater by PMS. • The doping sites of sulfur-doped g-C 3 N 4 have been investigated. • S doping can extend the light absorption range of the system. • PMS adsorption and activation were used to evaluate the performance of S-C 3 N 4. [ABSTRACT FROM AUTHOR]

The availability of new radioactive ion beams has broadened the study of nuclear reactions and nuclear structure. The main mechanism to produce the secondary beams is the fragmentation of the projectile. An alternative method for the production of the exotic nuclei is the multinucleon transfer. We measured production cross section for the B, C, N and O isotopes in the reaction18O + Ta and the beam energy at 10 MeV/nucleon. The cross sections were obtained by integrating the momentum distributions of the isotopes. It was shown that in deep inelastic processes the production yields of different isotopes could be well described using statistical models and could also be explained by the Qgg-systematic.

The BP unsaturated unit is a very attractive functional group as it provides novel reactivity and unique physical properties. Nonetheless, applications remain limited so far due to the bulky nature of B/P‐protecting groups, required to prevent oligomerization. Herein, we report the synthesis and isolation of a N‐heterocyclic carbene (NHC)‐stabilized phosphaborene, bearing a trimethylsilyl (TMS) functionality at the P‐terminal, as a room‐temperature‐stable crystalline solid accessible via facile NHC‐induced trimethylsilyl chloride (TMSCl) elimination from its phosphinoborane precursor. This phosphaborene compound, bearing a genuine B=P bond, exhibits a remarkable ability for undergoing P‐centre metathesis reactions, which allows the isolation of a series of unprecedented phosphaborenes. X‐ray crystallographic analysis, UV/Vis spectroscopy, and DFT calculations provide insights into the B=P bonding situation. [ABSTRACT FROM AUTHOR]

An experimental study of the helium-cluster decays of the 12Be excited states has been performed using the 9Li + 7Li → α + α + 8He and 9Li + 7Li → α + 6He + 6He reactions at the 9Li beam energy of 74.8 MeV. At excitation energies between 10 and 25 MeV, the 12Be excited states decaying into the 4He + 8He, 6He + 6He, and 6He + 6He*(1.8 MeV, Jπ = 2+) have been observed. Most of the observed states decaying into the 4He + 8He and 6He + 6He correspond to previously reported states. The decay to the 6He + 6He*(1.8 MeV, Jπ = 2+) channel has been observed for the first time. Two of the five states observed in this new decay channel are also observed in the ground state channel 6He + 6He, while two may correspond to the 4He + 8He decaying states. The states around 13.5 and 20.0 MeV decay to the 6He + 6He and 4He + 8He channels, while the state around 22.3 MeV decays into all three decay channels examined. This experiment is complementary to all previous studies of the 12Be cluster states because of the different reaction mechanisms used for the population of the 12Be cluster states. The observation of the states at high excitations with these exotic decay properties strongly supports the molecular structure of the 12Be excited states.

We report on the development of a custom particle detection system that aims to improve the detection capabilities of the ROSPHERE array. The detector is designed specifically for lifetime measurements using the in-beam Fast-timing method for nuclear states in nuclides produced in nuclear transfer reactions. An 80 x 3.6 mm disc of BC400 plastic scintillator was coupled to a sparse SiPM array readout connected to a dedicated Front End Electronics board. The detector was tested versus a conical LaBr 3 (Ce) coupled to a Hamamatsu PMT readout. The timing measurements resulted in a resolution of 896(5) ps. The detector design, characteristics, and performances are presented in this paper along with future improvements. [ABSTRACT FROM AUTHOR]

These lectures, held at a school at the Galileo Galilei Institute for Theoretical Physics, give a survey of the formalism, the methods and achievements of nuclear direct reaction theory. After recapitulating the principles of quantum scattering theory, projection techniques are used to reduce the complexities of nuclear reactions to the manageable level of a set of a few selected coupled channels interacting via effective operators. Direct reactions are introduced as fast reactions proceeding preferentially through the excitation of doorway components of the nuclear many-body configurations, corresponding to a separation of scales in energy and momentum transfer. The concept of the optical model is introduced and applied to elastic scattering on nuclei. The coupled channel T-matrix formalism is discussed for pion-induced reactions on the nucleon. Applications of direct reaction to theory are illustrated for transfer reactions, inelastic scattering, and single and double charge exchange reactions with light and heavy ions. [ABSTRACT FROM AUTHOR]

The use of [Cp′′2Zr(η1:1‐E4)] (E=P (1 a), As (1 b), Cp′′=1,3‐di‐tert‐butyl‐cyclopentadienyl) as phosphorus or arsenic source, respectively, gives access to novel stable polypnictogen transition metal complexes at ambient temperatures. The reaction of 1 a/1 b with [CpRNiBr]2 (CpR=CpBn (1,2,3,4,5‐pentabenzyl‐cyclopentadienyl), Cp′′′ (1,2,4‐tri‐tert‐butyl‐cyclopentadienyl)) was studied, to yield novel complexes depending on steric effects and stoichiometric ratios. Besides the transfer of the complete En unit, a degradation as well as aggregation can be observed. Thus, the prismane derivatives [(Cp′′′Ni)2(μ,η3:3‐E4)] (2 a (E=P); 2 b (E=As)) or the arsenic containing cubane [(Cp′′′Ni)3(μ3‐As)(As4)] (5) are formed. Furthermore, the bromine bridged cubanes of the type [(CpRNi)3{Ni(μ‐Br)}(μ3‐E)4]2 (CpR=Cp′′′: 6 a (E=P), 6 b (E=As), CpR=CpBn: 8 a (E=P), 8 b (E=As)) can be isolated. Here, a stepwise transfer of En units is possible, with a cyclo‐E42− ligand being introduced and unprecedented triple‐decker compounds of the type [{(CpRNi)3Ni(μ3‐E)4}2(μ,η4:4‐E′4)] (CpR=CpBn, Cp′′′; E/E′=P, As) are obtained. [ABSTRACT FROM AUTHOR]

The redox chemistry of the heterobimetallic triple‐decker complexes [(Cp*Fe)(Cp′′′Co)(μ,η5:η4‐E5)] (E=P (1), As (2), Cp*=1,2,3,4,5‐pentamethyl‐cyclopentadienyl, Cp′′′=1,2,4‐tri‐tertbutyl‐cyclopentadienyl) and [(Cp′′′Co)(Cp′′′Ni)(μ,η3:η3‐E3)] (E=P (10), As (11)) was investigated. Compound 1 and 2 could be oxidized to the monocations 3 and 4 and further to the dications 5 and 6, while the initially folded cyclo‐E5 ligand planarizes upon oxidation. The reduction leads to an opposite change in the geometry of the middle deck, which is now folded stronger into the direction of the other metal fragment (formation of monoanions 7 and 8). For the arsenic compound 8, a different behavior is found since a fragmentation into an As6 (9) and As3 ligand complex occurs. The Co and Ni triple‐decker complexes 10 and 11 can be oxidized initially to the heterometallic monocations 12 and 13, which are not stable in solution and convert selectively into the homometallic nickel complexes 14 and 15 and the cobalt complexes 16 and 17. This behavior was further proven by the oxidation of [(Cp′′′Co)(Cp′′Ni)(μ,η3:η2‐P3)] (19, Cp′′=1,3‐di‐tertbutyl‐cyclopentadienyl) comprising two different Cp ligands. The transfer of {CpRM} fragments can be suppressed when a {W(CO)5} unit is coordinated to the P3 ligand (20) prior to the oxidation and the mixed cobalt and nickel cation 21 can be isolated. The reduction of 10 and 11 yields the heterometallic monoanions 22 and 23, where no transfer of the {CpRM} fragments is observed. [ABSTRACT FROM AUTHOR]

Nuclear reaction rates are one of the most important ingredients in describing how stars evolve. The study of the nuclear reactions involved in different astrophysical sites is thus mandatory to address most questions in nuclear astrophysics. Direct measurements of the cross-sections at stellar energies are very challenging–if at all possible. This is essentially due to the very low cross-sections of the reactions of interest (especially when it involves charged particles), and/or to the radioactive nature of many key nuclei. In order to overcome these difficulties, various indirect methods such as the transfer reaction method at energies above or near the Coulomb barrier are used to measure the spectroscopic properties of the involved compound nucleus that are needed to calculate cross-sections or reaction rates of astrophysical interest. In this review, the basic features of the transfer reaction method and the theoretical concept behind are first discussed, then the method is illustrated with recent performed experimental studies of key reactions in nuclear astrophysics.

We test the sensitivity of transfer reactions to the bound state wave functions within a distorted wave Born approximation formalism. Using supersymmetric transformations, we remove the Pauli-forbidden states from the two-body potentials and generate an equivalent supersymmetric partner. Wave functions from these potentials have the same asymptotics, but they differ in the nuclear interior. This allows us to study the influence of the nuclear interior on transfer cross sections. We apply the calculations to the O16(d,p)17O and C12(7Li, t)16O reactions, which are typical examples of nucleon and α transfer, respectively. The spectroscopic factors for 17O are decreased by about 30% when using supersymmetric potentials. For 16O, the differences are smaller. However, we show that ambiguities exist in the determination of the spectroscopic factors, due to the choice of the angular range where the fit is performed.

We used a high-resolution magnetic spectrograph to study neutron pair-correlated 0+ states in 136Ba, produced via the Ba138(p,t) reaction. In conjunction with state-of-the-art shell model calculations, these data benchmark part of the dominant Gamow-Teller component of the nuclear matrix element (NME) for 136Xe neutrinoless double beta (0νββ) decay. We demonstrate for the first time an evaluation of part of a 0νββ decay NME by use of an experimental observable, presenting a new avenue of approach for more accurate calculations of 0νββ decay matrix elements.

We present different reaction models commonly used in nuclear astrophysics, in particular for the nucleosynthesis of the light elements. Nuclear reactions involved in stellar evolution generally occur at energies much lower than the Coulomb barrier. This property makes the cross sections extremely small, and virtually impossible to be measured in the laboratory. We start with a general discussion of low-energy scattering, and define the various cross sections required for reaction networks (essentially radiative capture and transfer reactions). Then we present specific models. Microscopic theories are based on fundamental principles, such as a nucleon-nucleon interaction, and an exact account of the antisymmetrization between all nucleons. In this context, most calculations performed so far have been done in the cluster approximation, but recent works, referred to as “ab initio” models, go beyond this approximation. Microscopic models can be simplified by neglecting the internal structure of the colliding nuclei, which leads to the potential model, also named the optical model. An alternative approach for the theoretical analysis of the experimental data is based on the phenomenological R-matrix theory, where parameters are fitted to the existing data, and then used to extrapolate the cross sections down to stellar energies. Indirect approaches, such as the Trojan Horse method, are briefly outlined. Finally, we present some typical applications of the different models.