Catalytic Effect of Transition Metal Complexes of Triaminoguanidine on the Thermolysis of Energetic NC/DEGDN Composite

The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.

Synthesis and Physico-Chemical Characterizations of Novel Hydrazone Ligands and Their Metal Complexes against Hormone-Dependent and Independent Cancers

This work deals with the synthesis and physicochemical characterizations of a new group of novel retinoidal ligands and their metal complexes. Their in vitro anti-proliferative activities have shown that ligand L1 is effective against human breast cancer BT-20 and MCF-7 cell lines. At the same time, compound L2 exerts its effect on human prostate cancer PC-3 and human breast cancer MDA-MB-231 and MCF-7 cell lines respectively. The retinoid ligands exert their pleiotropic action toward retinoic acid receptors (RARs) than their metal complexes but all compounds exhibit concentration-dependent.

3,6-Bis-β-Dicarbonylsubstituted Carbazoles Bearing N-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu3+ ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.

Synergistic Optimization of Buried Interface by Multifunctional Organic-Inorganic Complexes for Highly Efficient Planar Perovskite Solar Cells

For the further improvement of the power conversion efficiency(PCE)and stability of perovskite solar cells(PSCs),the buried interface between the perovskite and the electron transport layer is crucial.However,it is challenging to effectively optimize this interface as it is buried beneath the perovskite film.Herein,we have designed and synthesized a series of multifunctional organic-inorganic(OI)complexes as buried interfacial material to promote electron extraction,as well as the crystal growth of the perovskite.The OI complex with BF4−group not only eliminates oxygen vacancies on the SnO_(2) surface but also balances energy level alignment between SnO_(2) and perovskite,providing a favorable environment for charge carrier extraction.Moreover,OI complex with amine(−NH_(2))functional group can regulate the crystallization of the perovskite film via interaction with PbI2,resulting in highly crystallized perovskite film with large grains and low defect density.Consequently,with rational molecular design,the PSCs with optimal OI complex buried interface layer which contains both BF4−and−NH_(2) functional groups yield a champion device efficiency of 23.69%.More importantly,the resulting unencapsulated device performs excellent ambient stability,maintaining over 90%of its initial efficiency after 2000 h storage,and excellent light stability of 91.5%remaining PCE in the maximum power point tracking measurement(under continuous 100 mW cm−2 light illumination in N2 atmosphere)after 500 h.

DNA-free genome editing in grapevine using CRISPR/Cas9 ribonucleoprotein complexes followed by protoplast regeneration

CRISPR/Cas9 genome editing technology can overcome many limitations of traditional breeding,offering enormous potential for crop improvement and food production.Although the direct delivery of Cas9-single guide RNA(sgRNA)ribonucleoprotein(RNP)complexes to grapevine(Vitis vinifera)protoplasts has been shown before,the regeneration of edited protoplasts into whole plants has not been reported.Here,we describe an efficient approach to obtain transgene-free edited grapevine plants by the transfection and subsequent regeneration of protoplasts isolated from embryogenic callus.As proof of concept,a single-copy green f luorescent protein reporter gene(GFP)in the grapevine cultivar Thompson Seedless was targeted and knocked out by the direct delivery of RNPs to protoplasts.CRISPR/Cas9 activity,guided by two independent sgRNAs,was confirmed by the loss of GFP f luorescence.The regeneration of GFP−protoplasts into whole plants was monitored throughout development,confirming that the edited grapevine plants were comparable in morphology and growth habit to wild-type controls.We report the first highly efficient protocol for DNA-free genome editing in grapevine by the direct delivery of preassembled Cas9-sgRNA RNP complexes into protoplasts,helping to address the regulatory concerns related to genetically modified plants.This technology could encourage the application of genome editing for the genetic improvement of grapevine and other woody crop plants.

Encapsulation of Ru(II) Polypyridine Complexes for Tumor-Targeted Anticancer Therapy

Ru(II)polypyridine complexes have attracted much attention as anticancer agents because of their unique photophysical,photochemical,and biological properties.Despite their promising therapeutic profile,the vast majority of compounds are associated with poor water solubility and poor cancer selectivity.Among the different strategies employed to overcome these pharmacological limitations,many research efforts have been devoted to the physical or covalent encapsulation of the Ru(II)polypyridine complexes into nanoparticles.This article highlights recent developments in the design,preparation,and physicochemical properties of Ru(II)polypyridine complex-loaded nanoparticles for their potential application in anticancer therapy.

Probing electronic structures of transition metal complexes using electron paramagnetic resonance spectroscopy

Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work.

A Theoretical Study of Tris-(o-benzoquinonediimine)-First-Row Divalent Transition Metal Complexes

The ligand o-phenylenediamine (opda) and its oxidized form, o-benzoquinonediimine (bqdi), act as a fascinating candidate coordinating toward transition metal ions leading to the photochemical hydrogen production in absence of photosensitizers. Herein, we report the systematic study of the interaction between the oxidized form bqdi ligand, tris-(o-benzoquinonediimine) with divalent first-row transition metal series using DFT calculations. The lowest energy structures, bond length, binding energies, frontier molecular orbital analysis, natural bond orbitals, and global reactivity descriptor were calculated using B3LYP/6-311G(d,P) level of theory. The time dependent-DFT at the CAM-B3LYP/6-311+G(d,p) level of theory was applied to determine the electronic structures and the optical spectra. The theoretical binding trend of the divalent first-row transition metal series is decreasing as follows: Cu >Ti > V > Co > Ni > Fe > Cr > Zn >Mn. Among them, the binding potency of iron (II) by the bqdi ligand was not predominantly sturdy as compared to other first-row divalent transition metal ions. The origin of strong coordination with Fe(II) is attributed to its extra capability to induce covalent coordination of bqdi ligands. The complex exhibited two strong peaks at 370 nm and 452 nm, due to the HOMO-3 to LUMO+1 and HOMO-1 to LUMO transitions, respectively. Natural bond orbital analysis showed that the major interaction happens between the N lone pair electrons of the ligand with an anti-bonding orbital of metal ions, in which Ti showed the highest interaction energy than other metal ions. The present systemic DFT study of bqdi ligands with the first-row transition metals strongly encourages the future establishment of photochemical hydrogen production in absence of photosensitizers.

Synthesis and Characterisation of Cr(III) and Co(II) Schiff Base Complexes

Co(II) and Cr(III) metal complexes of Schiff bases were synthesized from the condensation reaction between 4-(dimethylamino)benzaldehyde and 4-amino-3-hydroxy-naphthalene-1-sulfonic acid. Their structures were investigated by elemental analysis, molar conductance measurements, infrared spectroscopy, electronic spectroscopy, and 1HNMR spectroscopy. The elemental analysis data suggested a 1:1 [M:L] ratio for the complexes. The molar conductance measurements of the complexes indicate their electrolytic nature in DMSO as a solvent. The absorption bands in the electronic spectra verified an octahedral environment around the metal ions in the complexes.

Physicochemical and Analytical Studies of Some Monomer and Polymer Complexes Derived from Selected Aroyl Hydrazone

New solid complexes derived from the reaction of aroyl hydrazones, 2-hydroxy-1-naphthaldehyde benzene sulphonyl hydrazone (HNB), and 2-hydroxy-1-naphthaldehyde p-toluene sulphonyl hydrazone (HNT), with Co2+, Ni2+, and Cu2+ salts have been isolated and characterized using elemental analyses, spectral (UV-vis., IR), molar conductivity and magnetic measurements. The modes of bonding as well as the stereochemistry of the isolated solid complexes were discussed. The results suggested that both HNB and HNT coordinated with the metal ions in a bidentate manner forming a polymeric chain in the case of HNB while monocular complexes were formed in the case of HNT. The amounts of solvent in the solid complexes were determined by TGA measurements. Also, spectral studies of HNT with Co2+ and Fe3+ ions in solution were carried and the ratio of complexes was determined by continuous variation, molar ratio, and slope ratio methods. Moreover, the results suggest the formation of 1:1 (M:L) for Co2+ ions while three species with ratios of 1:1, 1:2, and 2:1 (M:L) have been observed in the case of Ni2+ and Cu2+. Finally, conductance titration of HNB and HNT with Co2+ ion elucidates the formation of two species with ratios 1:1 and 1:2 (M:L) in the case of the Co2+-HNB while 1:1 (M:L) belongs to the Co2+-HNT system.

Pathfinder-Based Simulation and Optimization of Evacuation of Large Commercial Complexes

Large commercial complexes are large in scale, complex in function, and located in densely populated areas that are prone to casualties due to unfavorable evacuation. To comprehend the safety evacuation of large commercial complex buildings in China, investigate the safety evacuation problems encountered during the evacuation process and the evacuation optimization design strategy, the paper uses Pathfinder to build a simulation model based on literature research and study to simulate the evacuation of personnel in a large commercial complex in Dalian and explore its problems during the evacuation process. The results show that the type of personnel has an effect on the large commercial complex’s evacuation simulation results;the total number of evacuees is non-linearly correlated with the time change curve;some staircases take a long time to evacuate and have a low utilization rate. To improve evacuation efficiency, optimization suggestions for safety exits, evacuation stairs, and evacuation channels are made based on the results.

2,4-Dinitrophenyl Ether of Polyvinyl Alcohol and Polymer Bound Anionic SIGMA Complexes

A new electrophilic polymer, 2,4-dinitrophenyl ether of polyvinyl alcohol (PVA-DNP), having a degree of substitution of 0.5 was prepared from polyvinyl alcohol (PVA) and 1-fluro-2,4-dinitrobenzene (DNFB). The PVA-DNP polymer was characterized by NMR, IR, and UV-visible spectroscopy. The reaction of PVA-DNP with sodium methoxide was followed by NMR and UV-visible spectroscopy. Evidence of polymer bound spirocyclic SIGMA complex, C-1 and C-3 polymer bound DNP-methoxy SIGMA complexes and the formation and C-1 methoxy complex of 2,4-dinitroanisole was observed.

Synthesis and Photophysical Properties of Dy^(3+) and Gd^(3+) Polymeric Complexes with Functionalized Polybenzimidazole Containing β-Diketone Side Group

The polymeric ligand PBIa （functionalized polybenzimidazole containing β-diketone side group） was successfully synthesized via the reaction of polybenzimidazole （PBI） with 3-Br-acetylacetone in DM SO solvent using Nail as the deprotonation reagent. Its corresponding polymeric complexes of Dy^3＋ and Gd^3＋ were prepared and characterized by FT-IR, ^1H NMR, molar conductance measurements, and thermal analysis. The photoluminescence properties and the probable mechanism of the Dy and Gd complexes were studied. The measurement and analysis of the thermal properties showed that these were thermal stable.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(V)-SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 2,2'-DINITRO-4,5,4',5'-BIS-(15-CROWN-5)-DIBENZO DISULFIDE

Three new solid complexes of macrocyclic polyether ligand 2, 2'-dinitro-4, 5, 4', 5'bis-(15- crown-5)-dihenzo disulfide(L) with trivalent rare earth nitrates having composition of RE(NO_3)_3·L ·6H_2O(RE=Ce, Pr, Nd) have been synthesized in acetonitrile. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X-ray powder diffraction analysis, molar conductance and measurements of solubility in some general solvents.

Cleavage of Nucleotides by Lanthanide Metal Complexes

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Metal Complexes of Antibiotic Pipemidic Acid

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Electronic Structures of Mono-and Bi-nuclear Benzene-Transition Metal Sandwich Complexes

We report here the calculations on electronic structures of mono- and bi-nuclear benzene - transition metal sandwich complexes by means of CNDO/2 program, on the basis of molecular orbital components, atomic net charges and bond orders, the bonding pictures are analysed and discussed.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4'-BROMO-5'-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)with Uivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0, RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char- acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powder diffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows that coordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.

Comparative Studies between Chemical and Tribochemical Reactions of Some Metal Complexes Derived from N-(O-Hydoxyphenyl)-N'-phenylthiourea (L)

The reactions of N-(O-hydoxyphenyl)-N'-phenylthiourea (L) derived from with Cu+, Cu2+, Co2+ and Co3+ chloride and/or iodide afford new metal complexes. The isolated complexes were synthesized by two different techniques (chemical and tribochemical methods). Two complexes were synthesized by the direct chemical reactions of N-(O-hydoxyphenyl)-N'-phenylthiourea (L) with MCl2·XH2O (M = Co2+ and Cu2+;X = 6 in case of Co2+ and X = 2 in case of Cu2+) in absolute EtOH. The general formulae of the two complexes derived by the chemical method are [Cu(L)2(EtOH)2]Cl2 and [Co(L)2Cl2]Cl. These complexes were used to synthesize another two complexes using tribochemical reaction by grinding the previous chloride complexes with excess KI in agate mortar in the solid state. The isolated complexes have the general formulae, [Cu(L)I·H2O]·1/2H2O and [Co(L)I3(Et- OH)]·3EtOH. The results indicate the substitution of the chloride by iodide ions during grinding and extraction of the complexes by solvents. The IR spectra of the complexes suggest that L acts in a bidentate manner towards the metal ions. Moreover, the results of electronic spectra and magnetic measurements for the chloride complexes suggest distorted-octahedral structure for Cu2+ and low-spin octahedral structures around the CoII and Cu2+ ions, respectively. On the other hand the data suggest that the iodide complexes have square-planer and low-spin for the Cu+ and Co3+ ions, respectively. The results of mass spectra confirm the formulae proposed for the isolated complexes. The mechanisms of reduction of CuII and oxidation of CoII for the metal complexes were elucidated.