Overrun phenomenon and neutron yield in Coulomb explosion of deuterated alkane clusters driven by intense laser field

By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane（CD4）N, ethane（C2D6）N and propane（C3D8）N clusters are simulated numerically.The overrun phenomenon that the deuterons overtake the carbon ions inside the expanding clusters, as well as the dependence of the energetic deuterons and fusion neutron yield on cluster size, is discussed in detail. Researches show that the average kinetic energy of deuterons and neutron yield generated in the Coulomb explosion of（C2D6）N cluster are higher than those of（CD4）N cluster with the same size, in qualitative agreement with the reported conclusions from the experiments of（C2 H6）N and（CH4）N clusters. It is indicated that（C2D6）N clusters are superior to（CD4）N clusters as a target for the laser-induced nuclear fusion reaction to achieve a higher neutron yield. In addition, by comparing the relevant data of（C3D8）N cluster with those of（C2D6）N cluster with the same size, it is theoretically concluded that（C3D8）N clusters with a larger competitive parameter might be a potential candidate for improving neutron generation. This will provide a theoretical basis for target selection in developing experimental schemes on laser-driven nuclear fusion in the future.

Characteristics of Laser-Induced Surface and Bulk Damage of Large-Aperture Deuterated Potassium Dihydrogen Phosphate at 351 nm

Deuterated potassium dihydrogen phosphate damage performance at 351 nm is studied on a large-aperture laser system. Bulk and rear-surface damage are initiated under the 3ω fluences of 6.T J/cm2 and 33/cm2, and show different growth characteristics under multiple laser irradiations with the fluence of 6 J/cm2. The size and number of bulk damage keep unchanged once initiated. However, surface damage size also does not grow, while surface damage number increases linearly with laser shots. Different damage thresholds and growth behaviors suggest different formations of bulk and surface damage precursors. The cause of surface damage is supposed to be near-surface absorbing particles buried under the sol-gel coating.

Synthesis and Pharmacokinetic Property Improvement of Deuterated Plinabulin 9

Plinabulin,a potent microtubule-targeting agent,is derived from marine natural diketopiperazine ‘phenylahistin'.To develop novel plinabulin analogue that could display better pharmacokinetic properties and less side effects,deuterated plinabulin 9 was synthesized and evaluated in vitro and in vivo.In comparison with plinabulin,in vivo pharmacokinetic studies indicated that the deuterated derivative 9 could alter blood circulation behavior obviously,which was proved by increased area under the plasma concentration-time curve(AUC_(0–∞)),reduced clearance(CL),and prolonged total body mean residence time(MRT).The derivative 9 also has higher inhibition rates against Bx PC-3,Jurkat and A-431 tumor cell lines as compared with its prototype plinabulin.Therefore,the deuterated compound 9 might be developed as a potential agent for different cancer treatments.

Effects of deuteration on the structure of NH_4H_2PO_4 crystals characterized by neutron diffraction

A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level in the crystals is lower compared with the aqueous growth solution. The deuterium segregation coefficient in the crystals decreases with increasing deuterium content of the solution. The deuterium content in the NH_4^+ group is higher than that in H_2PO_4^- group.In addition, the variations of lattice parameters are shown here.

Coulomb expansion of deuterated methane clusters irradiated by an ultrashort intense laser pulse

The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse, the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expanding carbon ions, resulting in the creation of two separated subelusters. The enhanced deuteron kinetic energy and a narrow peak around the energy maximum in the deuteron energy distribution make a considerable contribution to the efficiency of nuclear fusion compared with the ease of homonuelear deuterium clusters. With the intense laser irradiation, the nuclear fusion yield increases with the increase of the cluster size, so that deuterated heteronuelear clusters with larger sizes are required to achieve a greater neutron yield.

Electrical Conduction in Deuterated Ammonium Dihydrogen Phosphate Crystals with Different Degrees of Deuteration

Conductivity measurements of deuterated ammonium dihydrogen phosphate （DADP） crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-direction is larger than that of the e-direction. Compared with DKDP crystals, DADP crystals have larger conductivities, which is partly due to the existence of A defects. The ac conductivity over the temperature range 25-170℃has shown a knee in the curve ofln（σT） versus T-1. The conductivity activation energy calculated by the slope of the high temperature region decreases with the deuterium content. The previously reported phase transition is not seen.

Study of the deuterated titanium Ti^2H_x sample by using nuclear reaction analysis and material analysis methods

Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atomic: ratio X =2H/Ti≥1.6. The change of the surface topography and rnicrostructurc of the sample before and after loading was observed by using Scan Electron Microscopy (SEM). The surface segregation of the samples after deutcron bombardment was also observed. A fluctuatingly-incrcasing trend of the deutcriuin density in titanium target was detected in the deuteron implantation experiments. which indicated a suddenly explosion (segregation) or fast diffusion of deuterium in the titanium. Significant amount of nitrogen contamination was found in thc Ti2Hx sample by nuclear reaction analysis (NRA), which indicated that the Ti2Hx structure might have the feature to trap nitrogen from air. The nitrogen contamination in Ti2Hx significantly affects the increase of the atomic ratio X

Recent Advances in Deuteration Reactions

The deuteration of organic compounds has attracted more attentions in recent years for the potential applications in new drug discovery and synthetic chemistry.For this purpose,many efficient deuterium labeling methodologies have been developed,including hydrogen isotope exchange(HIE),reductive deuteration,and dehalogenative deuteration that allow for the synthesis of selectively deuterated compounds.In the last few years,great breakthroughs in selective isotope labeling have been achieved and the interest in new methodologies for the deuteration of organic molecules is rising.In this review,we summarized the recent developments in the selective deuteration of organic molecules since 2021.Several types of key processes in deuterium incorporation reactions,including H/D exchange,reductive deuteration and dehalogenative deuteration,are introduced and discussed.

Electrochemical Mono-Deuterodefluorination of Trifluoromethyl Aromatic Compounds with Deuterium Oxide

The deuterodifluoromethyl group CF_(2)D combines the structural features of CF_(3) and CD_(3) groups,finding wide applications in diverse pharmaceutical entities.In this work,the electrochemical monodeuterodefluorination of Ar-CF_(3) to Ar-CF_(2)D is achieved with an unreported deuterium atom transfer-coupled electron transfer pathway using D_(2)O as the only D source for the first time.A series of Ar-CF_(3) substances,including commercial pharmaceuticals,were converted to corresponding CF_(2)D products in up to 91% yield and 97% D-incorporation.A variety of functional groups,including pyridine,pyrrole,furan,thiophene,borate,thio ether,amine,amide,sulfonamide,and halide,are well tolerated in this protocol.t-BuOLi was an essential reagent to achieve chemoselective mono-defluorination.

Highly efficient electrocatalytic deuteration of acetylene to deuterated ethylene using deuterium oxide

Deuterated ethylene is an important building block for manufacturing various deuterated polyolefins and chemicals.However,low-cost and large-scale production of deuterated ethylene still remain a great challenge.Herein,with D_(2)O as the D source,we first propose an electrocatalytic deuteration strategy for continuous production of deuterated ethylene from acetylene under ambient conditions.Specially,Ag nanoparticles exhibit a very high deuterated ethylene Faradic efficiency of up to 99.3%at-0.6 V vs.reversible hydrogen electrode.Meanwhile,Ag nanoparticles achieve a deuterated ethylene production rate of 3.72×10^(3)mmol h^(-1)g^(-1)cat and an excellent long-term stability with deuterated ethylene Faradaic efficiencies of~95%in a two-electrode flow cell,which substantially outperform state-of-the-art values for previously reported deuterated alkenes.In-situ electrochemical Infrared absorption and Raman spectroscopies reveal superior acetylene absorption and formation of deuterated ethylene on Ag nanoparticles.This efficient electrocatalytic deuteration strategy opens a new window for continuous and economic production of deuterated alkenes.

Electrocatalytic water-splitting for the controllable and sustainable synthesis of deuterated chemicals

Tandem water electrolysis for the transformation of universal feedstock to value-added chemicals integrated with hydrogen generation and in situ utilization is a promising approach to address the economic challenges of electrochemical hydrogen evolution and storage.Herein,we present the controllable electrocatalytic deuteration of halides using inexpensive and reusable heavy water(D2 O)as a D-source for the preparation of valuable D-labelled chemicals and pharmaceuticals under mild conditions.This electrochemical deuteration method with high efficiency and selectivity furnishes a series of D-labelled chemicals and pharmaceuticals in high yields with excellent D-incorporation.The reaction efficiency and selectivity,that is,the precise substitution of deuterium atoms at different halogen positions,can be tuned by varying the applied voltages.The results show the great potential of green and economical electrocatalytic methods for producing value-added fine chemicals in addition to hydrogen evolution.

Facile and Economical Electrochemical Dehalogenative Deuteration of(Hetero)Aryl Halides

Deuterated compounds are valuable in synthetic,pharmaceutical,and analytical chemistry.The deuteration of halides is a widespread method for highly site-selective deuterium installation.However,the facile,efficient,and economical deuterium incorporation remains challenging.In this work,we introduced a practical deuteration of(hetero)aryl halides through an electrochemical reduction method.This transformation proceeded smoothly at room temperature without metal catalysts,external reductants,or toxic or dangerous reagents.Remarkably,low-cost and chemically equivalent D2O was the sole deuterium source in this reaction.Professional electrosynthesis equipment was not essential because we demonstrated common batteries and electrodes were enough for this reaction.

Deuterated N-difluoromethylthiophthalimide:A stable,scalable reagent for radical and electrophilic deuteriodifluoromethylthiolations

A new,stable and scalable reagent for deuteriodifluoromethylthiolation(deuterated N-difluoromethylthiophthalimide,PhthSCF_(2)D)has been developed.This reagent can be applied for the photocatalytic radical deuteriodifluoromethylthiolation of various olefins and aldehydes(30 examples).Meanwhile,it can achieve the electrophilic deuteriodifluoromethylthiolation of a series of electrophilic substrates including electron-rich arenes,aryl/vinylboronicacids,alkynes,amines,thiols andβ-ketoesters(22 examples).Some complex molecules can also be applied in both radical and electrophilic deuteriodifluoromethylthiolation using PhthSCF_(2)D as the reagent.

Transition metal-free photocatalytic reductive deuteration of ketone derivatives

Deuterium labelling techniques have shown widespread applications in organic synthesis,analytic chemistry,life science and material science.The design of practical deuteration reactions which is environmentally friendly is highly desired for pharmaceutical development and industrial processes while remaining underexplored.We herein report a convenient,transition metal-free strategy for reductive deuteration of ketone derivatives toα-deuterated alcohols by employing a conjugated aryl amine-based organophotocatalyst,a dipropyl disulfide cocatalyst and an inorganic reductant.Upon irradiation with visible light and under an air atmosphere,a variety of diaryl ketones,heteroaryl ketones,cyclic ketones,α-ketoesters,benzil derivatives,aliphatic ketones and drug-like molecules were converted into correspondingα-deuterated aryl alcohols in good to excellent yields and with high deuterium incorporation(up to 99%D-incorporation).Only low toxic side-products,such as sodium salts and carbon dioxide,were generated.Consequently,the synthetic utility of this method is highlighted by the preparation of several D-labeled drug-like molecules,including orphenadrine,carbinoxamine and modafinil.

Rapid growth and properties of large-aperture 98%-deuterated DKDP crystals

In this paper,a highly deuterated potassium dihydrogen phosphate(DKDP)crystal with sizes up to 318 mm×312 mm×265 mm was grown by the rapid-growth method.The synthesis tank device was specially designed to synthesize a higher deuterium concentration and high-purity DKDP solution.The deuterium content of the as-grown crystal,which was 97.9%,was determined by two methods,including infrared(IR)spectroscopy and thermo-gravimetric analysis(TGA)measurements.The performances of the 97.9%DKDP crystal,including transmission,absorption coefficient,and laserinduced damage threshold(LIDT)were measured.The results indicate that,in the near-infrared band,the transmission of the 97.9%DKDP crystal is higher than that of KDP and 70%DKDP crystals,and the absorption coefficient is lower.The LIDT of the crystal reached 23.2 J·cm^-2(R-on-1,1064 nm,3 ns),which meets the engineering requirements for use in optical applications.

A visible-light-photocatalytic water-splitting strategy for sustainable hydrogenation/deuteration of aryl chlorides

Hydrogenation/deuteration of carbon chloride(C–Cl)bonds is of high significance but remains a remarkable challenge in synthetic chemistry,especially using safe and inexpensive hydrogen donors.In this article,a visible-light-photocatalytic watersplitting hydrogenation technology(WSHT)is proposed to in-situ generate active H-species(i.e.,Had)for controllable hydrogenation of aryl chlorides instead of using flammable H2.When applying heavy water-splitting systems,we could selectively install deuterium at the C–Cl position of aryl chlorides under mild conditions for the sustainable synthesis of high-valued added deuterated chemicals.Sub-micrometer Pd nanosheets(Pd NSs)decorated crystallined polymeric carbon nitrides(CPCN)is developed as the bifunctional photocatalyst,whereas Pd NSs not only serve as a cocatalyst of CPCN to generate and stabilize H(D)-species but also play a significant role in the sequential activation and hydrogenation/deuteration of C–Cl bonds.This article highlights a photocatalytic-WSHT for controllable hydrogenation/deuteration of low-cost aryl chlorides,providing a promising way for the photosynthesis of high-valued added chemicals instead of the hydrogen evolution.

Visible Light Promoted Direct Deuteration of Alkenes via Co(III)–H Mediated H/D Exchange

We report herein a visible light-mediated direct deuteration of alkenes with D_(2)O or deuterated methanol(MeOD)using a cobaloxime as a hydrogen/deuterium(H/D)exchange catalyst.The synergistic photoredox/Co catalysis enabled facile deuterium(D)-incorporation of a variety of terminal and internal alkenes at either terminal or benzylic positions.We proposed that this process proceeded through a sequence of reversible addition-elimination reactions and fast proton exchange involving Co(III)–H,which was generated in situ by photoreduction.

Combining Neutron Scattering,Deuteration Technique,and Molecular Dynamics Simulations to Study Dynamics of Protein and Its Surface Water Molecules

Protein internal dynamics is essential for its function. Exploring the internal dynamics of protein molecules as well as its connection to protein structure and function is a central topic in biophysics. However, the atomic motions in protein molecules exhibit a great degree of complexities. These complexities arise from the complex chemical composition and superposition of different types of atomic motions on the similar time scales, and render it challenging to explicitly understand the microscopic mechanism governing protein motions, functions, and their connections. Here, we demonstrate that, by using neutron scattering, molecular dynamics simulation, and deuteration technique, one can address this challenge to a large extent.

Deuterated polyethylene nanowire arrays for high-energy density physics

The interaction of intense,ultrashort laser pulses with ordered nanostructure arrays offers a path to the efficient creation of ultra-high-energy density(UHED)matter and the generation of high-energy particles with compact lasers.Irradiation of deuterated nanowires arrays results in a near-solid density environment with extremely high temperatures and large electromagnetic fields in which deuterons are accelerated to multi-megaelectronvolt energies,resulting in deuterium–deuterium(D–D)fusion.Here we focus on the method of fabrication and the characteristics of ordered arrays of deuterated polyethylene nanowires.The irradiation of these array targets with femtosecond pulses of relativistic intensity and joule-level energy creates a micro-scale fusion environment that produced 2×10^(6)neutrons per joule,an increase of about 500 times with respect to flat solid CD2 targets irradiated with the same laser pulses.Irradiation with 8 J laser pulses was measured to generate up to 1.2×10^(7)D–D fusion neutrons per shot.