Laurence Marius Harwood

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Verified

Laurence verified their affiliation via an institutional email.

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• MA(Oxon), BSc, MSc, PhD(Manch); CSci, CChem FRSC, AFIChemE
• Emeritus Professor of Organic Chemistry at University of Reading

Introduction to Organic Spectroscopy aims to provide an understanding of spectroscopic techniques in the analysis of chemical structures. The book starts with an introduction to the theory. It then looks at ultra violet-visible spectroscopy. Next it considers infrared spectroscopy. Then it considers nuclear magnetic resonance spectroscopy in basic...

This chapter describes nuclear magnetic resonance (NMR) spectroscopy as the most powerful and versatile of all analytical techniques used by organic chemists. It highlights the spectroscopic features of NMR spectroscopy, which correlate with individual atoms within a molecule rather than groups of atoms. It also emphasizes the possibility of determ...

This chapter tells the history of the arrival of ultraviolet (UV) spectroscopic analysis during the 1930s, which was an important milestone in analytical chemistry. It demonstrated the advantages of non-destructive analysis. The chapter discusses the benefits brought by this development, such as vast savings in time, and the ability to work with mu...

Polar Rearrangements brings together the general principles of polar rearrangements in this study. The text deals with all the major rearrangements involving electron-deficient atoms or charged intermediates. Reactions involving migration to electron-deficient carbon, nitrogen, oxygen, and sulphur, and sigmatropic rearrangements involving polar spe...

The chapter provides some background on the development of non-destructive spectroscopic methods of analysis which can be carried out on small amounts of materials. This has provided the fundamental thrust behind the progress of organic chemistry. It looks at the identification of unknown molecules of high complexity which carry out samples that ra...

This chapter analyses the power of modern pulse-Fourier to transform nuclear magnetic resonance (NMR). The chapter then shows a variety of techniques that assist in the interpretation of spectra and allows for the routine observation of nuclei other than protons. It reviews the original motivation for establishing pulse-Fourier transform methodolog...

This chapter talks about a type of analysis which enables the mass of the molecule to be determined, including how it is constructed. It analyses the basic mass spectrometric experiment, first demonstrated by Wilhelm Wien in 1989, wherein individual molecules of a sample are bombarded with high energy electrons, causing the ejection of electrons fr...

This chapter discusses important classes of rearrangement in which the migration terminus is either an electron deficient nitrogen or an oxygen atom. It examines the migration of nucleophilic rearrangements to nitrogen that occur concurrently with the displacement of a substituent from the nitrogen or by a stepwise process involving initial fragmen...

This chapter highlights the principles behind infrared spectroscopy, focusing on the energy range of the infrared rays. These cause vibrational excitation of bonds within a molecule. It discusses stretching for higher energy and bending lower energy as the types of bond excitation. It also refers to the absorption of certain wavelengths of infrared...

Parallel-consecutive bimolecular reactions: a solution to the inverse kinetic problem and a characteristic equation involving the Lambert W function.

A seven-step synthetic route has been developed to access the labile C-3 unsubstituted 5-phenylthiomorpholinone system for the first time. The key step involved the nucleophilic ring opening of Boc-phenylmorpholinone to give the corresponding methyl ester. The sulfur introduction was accomplished through a Mitsunobu reaction to yield a thioacetate,...

We prepared Prussian blue (PB) nanoparticles immobilized on the surface of nanofibers to adsorb the Cs ions effectively. The nanofibers were fabricated by electrospinning of polyacrylonitrile (PAN), and polydopamine (PD) was polymerized to immobilize PB on the surfaces of the nanofibers. PD is known to adhere easily on any substrate, and could coat...

The fluorinated carbonate BK-1 solvent was studied as a diluent in extraction systems with different extracting agents-CMPO, THDGA, CyMe 4-BTBP, and CyMe 4-BTPhen, which are the most promising molecules for separation of minor actinides and lanthanides. Dependence of the extraction properties of the system on the concentrations of HNO 3 or extracti...

The extraction properties of tetra(4-hydroxyphenyl)BTPhen have been investigated. Liquid-liquid extraction studies in proposed SANEX diluents, cyclohexanone and 1-octanol, indicate that actinide-lanthanide separation is superior in cyclohexanone; whereas actinide-actinide separation is more efficient in 1-octanol. Immobilization of the ligand onto...

In this report, the interaction of monoamide/diamide and monoamide/diglycolamide mixtures with \({\text{UO}}_{2}^{2 + }\) are investigated in pH = 1 methanolic nitric acid media. These monoamides include N,N-dimethylacetamide (DMAA), N,N-diethylacetamide (DEAA), N,N-dibutylacetamide (DBAA) and N,N-dibutylbutanamide (DBBA). N,N,N′N′-tetraethylmalona...

Decommissioning is one of the most important phases in the life of a nuclear reactor, having a major influence on public perception of such technology. Therefore, development of technologies that make decommissioning more safe, effective and efficient is integral to the success of the nuclear industry. In this paper, phosphonic acid functionalised...

The thermodynamic parameters of the extraction system consisting of CyMe4-BTPhen dissolved in cyclohexanone and Am(III), Cm(III) and Eu(III) in HNO3 in the aqueous phase have been determined. Kinetic extraction experiments were carried out under various temperatures (15–45 °C) and the corresponding over-all mass transfer coefficients were used for...

The ultra-high pressure Menshutkin reaction of N-substituted imidazoles and α,ω-dichloroalkanes provides access to a wide variety of bis(imidazoliumyl)alkane dichlorides in an efficient, one-pot process. Although the substitution reactions of dichloromethane at ambient pressure can be exceedingly slow, at 1.9 GPa, syntheses are usually quantitative...

New type of "turn-on" fluorescent sensor for Cs ion was developed using a composite of blue-emissive conjugated polymer (CP) and graphene oxide (GO). Ethylene glycol units were introduced to the side chain of CP, which could interact with Cs ions. The CP and GO formed a stable, nonfluorescent composite, because of hydrophobic and 7t-7i interactions...

In this study, 5‐bromo‐2,9‐bis(5,6‐diphenyl‐1,2,4‐triazin‐3‐yl)‐1,10‐phenanthroline (5‐bromo‐Ph4‐BTPhen) was synthesized and evaluated for its ability to remove major radionuclides (Cs+, Sr2+, and Co2+). The synthesized ligand removed both Sr2+ and Co2+ from 1 mg/L aqueous solutions with extraction efficiencies of up to 99% at neutral and alkaline...

A CyMe4-BTPhen functionalized silica gel that selectively extracts Am(III) over Eu(III) from 4 M HNO3 with a separation factor > 154 has been developed. Evidence is presented that the counterion surrounding the M(III) in the proposed 1:1 [BTPhen:M(III)] complex plays an important role in the complexation of Am(III) and Eu(III).

A Prussian blue (PB)-embedded coordination polymer (COP) was prepared by simple incorporation of PB into a COP composed of 1,1,2,2-tetrakis(4-carboxyphenyl)ethane and the Zn ion during the synthesis of COP. The PB-COP was prepared as micro-sized particles with green emission (490 nm) from the strongly fluorescent tetraphenylethene group in the soli...

There is significant current interest in the application of magnetic (magnetite or maghemite) nanoparticles functionalised with chelating agents for the environmental remediation of metal contaminated waters and solutions. Whilst there is a body of knowledge about the potential remediation efficacy of such engineered nanoparticles from studies invo...

The synthesis of a novel 5-(4-vinylphenyl)-CyMe4-BTPhen actinide selective ligand using selenium free synthetic procedures is reported. For the first time, we report the electrospinning of this actinide selective ligand into a polystyrene fiber and investigate its selective removal of Am(III) from Eu(III) and Am(III) from Cm(III). At 4 M HNO3, the...

This article outlines some of the techniques and processes involved in the extraction of actinides that are present in spent nuclear fuel (SNF). Owing to the very similar chemistries of the actinides and lanthanides, it is difficult to differentiate the elements in a complex matrix of elements that are present in SNF. However, exploiting subtle cov...

A novel bis(1,2,4-triazin-3-yl)-dppz (dipyridophenazine) BTPhen ligand has been synthe-sised and screened for its ability to selectively extract Am(III) selectively from Eu(III) from 0.001 M-2 M HNO 3. The ligand showed preferential extraction for Am(III) over Eu(III) as the [HNO 3 ] increased towards 2 M with a reported separation factor (SF Am/Eu...

The complexation and extraction of the adjacent minor actinides Am(III) and Cm(III) by both hydrophobic and hydrophilic pre-organized 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) ligands has been studied in detail. It has been shown that Am(III) is extracted more rapidly than Cm(III) by the hydrophobic CyMe4–BTPhen ligand into different...

Complexation of Pu( iv ) with the actinide extractant CyMe 4 -BTPhen (2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline) was studied experimentally and by computational analysis.

The pKas of ethyl/butyl phosphonate silica (EBP-Si) have been determined, and the removal of cobalt and nickel from solution was investigated as a function of various parameters and compared with those of Purolite S950. pH uptake experiments suggested a combination of ion exchange and acid dissociation of the surface occurring. Isotherm data, fitte...

This paper describes a total synthesis of the terpene-derived natural product aritasone via the hetero-Diels-Alder [4+2] cyclodimerisation of pinocarvove, which represents the proposed biosyntheic route. The hetero-Diels-Alder dimerisation of pinocarvone did not proceed under standard conditions, and ultra-high pressure (19.9 kbar) was required. As...

The kinetic separation effect was observed leading to a separation factor for Am(III) over Cm(III) as high as 7.9 by using 2,9-bis-(1,2,4-triazin-3-yl)-1,10-phenantroline (BTPhen) ligands in our recent study. In an attempt to explain the observed tendencies, several kinetic models were tested. A model based on mass transfer as the rate-controlling...

Bis-(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) functionalized magnetic nanoparticles (MNPs), which selectively extract Am(III) over europium(III) from 0.1 M HNO3 with fast kinetics and a separation factor of 30 have been synthesized. These MNPs also show a small but significant selectivity for Am(III) over Cm(III) with a separation factor of...

A broad range of 1,10-phenanthroline substrates was efficiently C-H functionalised, providing rapid, gram-scale access to substituted heteroaromatic cores of broad utility. Furthermore, this C-H functionalisation pathway was extended to the synthesis of previously inaccessible, ultra-soluble, 2,9-bis-triazinyl-1,10-phenanthroline (BTPhen) ligands f...

The ability of diethylenetriaminepentaacetic acid (DTPA)-functionalised, silica-coated magnetic nanoparticles to adsorb Pb and Zn from single and bi-metallic metal solutions and from solutions containing dissolved organic carbon was assessed. In all experiments 10 mL solutions containing 10 mg of nanoparticles were used. For single metal solutions...

The first hydrophilic, 1,10-phenanthroline derived ligands consisting of only C,H,O and N atoms for a selective Am(III) extraction process are reported herein. One of these 2,9-bis-triazolyl-1,10-phenanthroline (BTrzPhen) ligands was found to exhibit process-suitable selectivity for Am(III) over Eu(III) and Cm(III), providing a clear step forward.

Novel BTBP [bis-(1,2,4-triazin-3-yl)-2,2’-bipyridine] / BTPhen [bis-(1,2,4-triazin-3-yl)-1,10-phenanthroline] functionalized silica gels have been developed to extract minor actinides, lanthanides and other fission products. BTPhen functionalized silica gel is capable of near-quantitative removal of Am(III) in the presence of Eu(III) from aqueous H...

Electronic modulation of CyMe4-BTPhen with 5-bromo and 5-(4-hydroxyphenyl) substituents leads to enhanced separation of Am(III) from Cm(III) over 0.1 – 3 M HNO3 (SFAm/Cm = ca. 9 at 0.1 M HNO3). In addition, substituting bromine atoms at the 5 and 6 positions of the phenanthroline backbone provides a mean of separating Am(III) from Eu(III) (SFAm/Eu...

The first examples of 4,7-disubstituted 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzo-triazin-3-yl)-1,10-phenanthroline (CyMe4-BTPhen) ligands are reported herein. Evaluating the kinetics, selectivity and stoichiometry of actinide(iii) and lanthanide(iii) radiotracer extractions has provided a mechanistic insight into the extraction pr...

Effects of chloro/bromo substitution at the 4-position of the pyridine ring of 6,6'-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzo[e][1,2,4]triazin-3-yl)-2,2'-bipyridine (CyMe4-BTBP) have been studied with regard to the extraction of Am(III) from Eu(III) and Cm(III) from 0.1 - 3 M HNO3. Similarly to CyMe4-BTBP, a highly efficient (DAm > 10 at 3 M...

An americium(III) selective separation procedure was developed based on the co-extraction of trivalent actinides (An(III)) and lanthanides (Ln(III)) by TODGA (N,N,N’,N’-tetraoctyl-diglycolamide), followed by Am(III) selective stripping using the hydrophilic complexing agent TS-BTPhen (3,3’,3’’,3’’’-[3-(1,10-phenanthroline-2,9-diyl)-1,2,4-triazine-5...

The reaction of geraniol with different lithium carbenoids generated from n-BuLi and the corresponding dihaloalkane has been evaluated. The reaction occurs in a chemo and stereoselective manner, which is consistent with a directing effect from the oxygen of the allylic moiety. Furthermore, a set of polyenes containing allylic hydroxyl or ether grou...

Herein, we report the synthesis of CyMe4-BTPhen-functionalized zirconia-coated (ZrO2) maghemite (γ-Fe2O3) magnetic nanoparticles (MNPs) and their ability to extract Am(III) from Eu(III) and Am(III) from Cm(III) in a range of HNO3 concentrations (0.001 - 4 M). Their extraction behavior is compared to our previously tested model based on silica-coate...

Recent efforts to develop molecules that are capable of separating the minor actinides(III) from inactive species such as lanthanides(III) are reviewed as a major contribution to the reprocessing of spent nuclear fuels. The principal chemical challenges are gradually being solved to such an extent that partitioning in conjunction with transmutation...

The novel hydrophilic back-extraction agent TS-BTPhen (3,3ʹ,3ʺ,3ʹʺ-[3-(1,10-phenanthroline-2,9-diyl)-1,2,4-triazine-5,5,6,6-tetrayl]tetrabenzenesulfonic acid) was tested for its selectivity towards Am(III) over Cm(III) and Eu(III) with a TODGA (N,N,Nʹ,Nʹ-tetraoctyldiglycolamide) based solvent. Batch experiments were carried out using TS-BTPhen diss...

We report the synthesis and evaluation of a novel hydrophilic 6,6-bis(1,2,4-triazin-3-yl)-2,2-bipyridine (BTBP) ligand containing carboxylate groups as a selective aqueous complexing agent for the minor actinides over lanthanides. The novel ligand is able to complex and separate Am(III) from Eu(III) in alkaline solutions selectively.

Fractionation of the methanol extract of the leaves of Oricia renieri and Oricia suaveolens (Rutaceae) led to the isolation of 13 compounds including the hitherto unknown furoquinoline alkaloid named 6,7-methylenedioxy-5-hydroxy-8-methoxy-dictamnine (1) and a flavanone glycoside named 5-hydroxy-4'-methoxy-7-O-[α-l-rhamnopyranosyl(1‴→5″)-β-d-apiofur...

In analysis of complex nuclear forensic samples containing lanthanides, actinides and matrix elements, rapid selective extraction of Am/Cm for quantification is challenging, in particular due the difficult separation of Am/Cm from lanthanides. Here we present a separation process for Am/Cm(III) which is achieved using a combination of AG1-X8 chroma...

We report the first examples of hydrophilic 6,6’-bis(1,2,4-triazin-3-yl)-2,2’-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) ligands, and their applications as actinide(III) selective aqueous complexing agents. The combination of a hydrophobic diamide ligand in the organic phase and a hydrophilic tetrasulfonated bis-...

Water soluble anionic and cationic bis-triazine ligands are able to suppress (mask) the extraction of corrosion and fission products such as Ni(II) and Pd(II) that are found in PUREX raffinates. Thus it is possible to separate these elements from the minor actinide Am(III). Although some masking agents have previously been developed that retard the...

It has been shown that modification of the phenanthroline backbone of CyMe4-BTPhen leads to subtle electronic modulation, permitting differential ligation of Am(III) and Cm(III) resulting in separation factors up to 7

It has been shown that CyMe4-BTPhen-functionalized silica-coated maghemite (γ-Fe2O3) magnetic nanoparticles (MNPs) are capable of quantitative separation of Am(III) from Eu(III) from HNO3 solutions. These MNPs also show a small but significant selectivity for Am(III) over Cm(III) with a separation factor of around 2 in 4 M HNO3. The water molecule...

Neocuproine has been covalently bound to silica-coated maghemite (a-Fe2O3) magnetic nanoparticles (MNPs) by a phenyl ether linkage. The resulting MNPs are able to remove Cu(II) from 12 ppm aqueous solution with an extraction efficiency of up to 99% at pH 2.

Review: recent progress on organic superbases, including their applications; 24 refs.

Bis-triazinylphenanthroline ligands (BTPhens), which contain additional alkyl (n-butyl and sec-butyl) groups attached to the triazine rings, have been synthesized, and the effects of this alkyl substitution on their extraction properties with Ln(III) and An(III) cations in simulated nuclear waste solutions have been studied. The speciation of n-but...

The 22nd annual symposium of the International Isotope Society's United Kingdom Group took place at the Møller Centre, Churchill College, Cambridge, UK, on Friday, 18 October 2013. The meeting was attended by 65 delegates from academia and industry; the life sciences; and chemical, radiochemical and scientific instrument suppliers. Delegates were w...

Neocuproine has been covalently bound to silica-coated maghemite (a-Fe2O3) magnetic nanoparticles (MNPs) by a phenyl ether linkage. The resulting MNPs are able to remove Cu(II) from 12 ppm aqueous solution with an extraction efficiency of up to 99% at pH 2.

This account describes the scientific events that have led from malonamides which coextract minor actinide and lanthanide fission products, to the 1,2,4-triazines such as BTBP and BTPhen reagents that are capable of separating Am(III) from Eu(III). The journey started with Mike Hudson having a walk in hot and dusty Rome with Claude Musikas of the C...

The term 'super base' is generally applied to ionic metal-containing bases that undergo irreversible proton abstraction. However, non-ionic powerful amine derivatives of amidines, guanidines, phosphazenes, and Verkade's bases with comparable or higher basicity to that of 1,8-bis(dimethylamino)naphthalene can all be arbitrarily classified as organic...

We describe herein preliminary studies on the intramolecular Diels-Alder furan mediated synthesis of 8-aryl-3,4-dihydroisoquinolin-1(2H)-ones, that constitutes a new, formal synthesis of indeno[1,2,3-ij]isoquinolines.

Effects of bromine substitution at the 5 and 5,6-positions of the 1,10-phenanthroline nucleus of BTPhen ligand on their extraction properties for Ln(iii) and An(iii) cations have been studied. Compared to C5-BTPhen, electronic modulation in BrC5-BTPhen and Br2C5-BTPhen enabled these ligands to be fine-tuned in order to enhance the separation select...

The direct selective separation of the trivalent actinides americium and curium from a simulated Plutonium Uranium Refining by EXtraction (PUREX) raffinate solution by a continuous counter-current solvent extraction process using miniature annular centrifugal contactors was demonstrated on a laboratory scale. In a 32-stage spiked test (12 stages fo...

The present work reports a convenient route for the immobilisation of a phenanthroline-bis triazine (C1-BTPhen) group on the surface of zirconia-coated maghemite (γ-Fe2O3) magnetic nanoparticles. The magnetic nanoparticles functionalized with C1-BTPhen were able to co-extract Am(III) and Eu(III) from nitric acid (HNO3). The extraction efficiency of...

Two members of the tetradentate N-donor ligand families 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) currently being developed for separating actinides from lanthanides have been studied. It has been confirmed that CyMe4-BTPhen 2 has faster complexation kinetics than CyMe4-BTBP 1....

A process comprising substitution of an acceptor molecule comprising a group —XC(O)— wherein X is O, S, or NR8, where R8 is C1-6 alkyl, C6-12 aryl or hydrogen, with a nucleophile, wherein the acceptor molecule is cyclised such that said nucleophilic substitution at —XC(O)— occurs without racemization, is provided. This process has particular applic...

Lanthanide(III) complexes with N-donor extractants, which exhibit the potential for the separation of minor actinides from lanthanides in the management of spent nuclear fuel, have been directly synthesized and characterized in both solution and solid states. Crystal structures of the Pr(3+), Eu(3+), Tb(3+), and Yb(3+) complexes of 2,9-bis(5,5,8,8-...

A series of bis-triazinylphenanthroline ligands (BTPhens) was synthesized by modifying the triazine substituents. It was found that varying these substituents altered the solubilities of the ligands in a number of non-polar solvents. Thus C5-BTPhen showed significantly higher solubility in octanol than C1-BTPhen. The high solubility of C5-BTPhen an...

The synthesis, lanthanide complexation and solvent extraction of An(III) and Ln(III) radiotracers from nitric acid solutions by a pre-organized, phenanthroline-derived bis-triazine ligand CyMe4-BTPhen are described. It was found that the ligand separated Am(III) and Cm(III) from the lanthanides with remarkably high efficiency, high selectivity, and...

Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe4-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO3, 3-methylcyclohexanone and 4-methylcyclo...

The removal of the most long-lived radiotoxic elements from used nuclear fuel, minor actinides, is foreseen as an essential step toward increasing the public acceptance of nuclear energy as a key component of a low-carbon energy future. Once removed from the remaining used fuel, these elements can be used as fuel in their own right in fast reactors...

The quadridentate N-heterocyclic ligand 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-2,2' : 6',2''-terpyridine (CyMe(4)-hemi-BTBP) has been synthesized and its interactions with Am(III), U(VI), Ln(III) and some transition metal cations have been evaluated by X-ray crystallographic analysis, Am(III)/Eu(III) solvent extraction e...

Four new 6,6′-bis(1,2,4-triazin-3-yl)-2,2′-bipyridine (BTBP) ligands, which contain either additional alkyl groups on the pyridine rings or seven-membered aliphatic rings attached to the triazine rings, have been synthesized, and the effects of the additional alkyl substitution in the 4- and 4′-positions of the pyridine rings on their extraction pr...

Studies towards the biomimetic synthesis of mycaperoxide B (1) are described. We have established the synthesis of four diastereoisomers of mycaperoxide B methyl ester (1a) by employing a Michael addition across an α,β-unsaturated ester precursor 2 as the key step. This result strongly suggests stereocontrol in the addition of the hydroperoxide fun...

This account summarizes recent work by us and others on the development of ligands for the separation of actinides from lanthanides contained in nuclear waste streams in the context of a future European strategy for nuclear waste management. The current status of actinide/lanthanide separations worldwide is briefly discussed, and the synthesis, dev...

https://www.oecd-nea.org/science/docs/2013/nsc-doc2013-3.pdf

The intramolecular Diels-Alder furan (IMDAF) cycloaddition reaction is a versatile pericyclic reaction for the regio-and stereoselective synthesis of 6-membered carbocyclic and heterocyclic rings. In this chapter, recent applications of this reaction in organic synthesis are reviewed, with a particular emphasis on its utility as a key step in the t...

The environmental implications of generating electric power from nuclear fission have been a matter of concern since the construction of the earliest nuclear reactors and power stations in the 1950s. After two or more decades of construction of nuclear power stations, this ceased in many countries, largely as a result of concerns for the environmen...

The synthesis, lanthanide complexation, and solvent extraction of actinide(III) and lanthanide(III) radiotracers from nitric acid solutions by a phenanthroline-derived quadridentate bis-triazine ligand are described. The ligand separates Am(III) and Cm(III) from the lanthanides with remarkably high efficiency, high selectivity, and fast extraction...

The synthesis and extraction of americium(III) and europium(III) from aqueous nitric acid solutions by the new BTBP ligands 6,6'-bis(5,5,7,7-tetramethyl-5,7-dihydrofuro[3,4-e]-1,2,4-triazin-3-yl)-2,2'-bipyridine (Cy5-O-Me4-BTBP), and 6,6'-bis(5,5,7,7-tetramethyl-5,7-dihydrothieno[3,4-e]-1,2,4-triazin-3-yl)-2,2'-bipyridine (Cy5-S-Me4-BTBP) is descri...

Condensation of leuco-5-hydroxyquinizarin with aldehydes under Marschalk conditions (sodium hydroxide – water) gives 2-alkyl-5-hydroxyquinizarins with high regioselectivity, while the 3-alkyl compounds are obtained under Lewis conditions (piperidinium acetate – isopropanol). Reaction of the quinone with nitronate anions in methanol yields 2-alkyl d...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Fractionation of a MeOH/CH2Cl2 (1/1) extract of the aerial parts of Senecio erechtitoides led to the isolation of six compounds including the hitherto unknown N-phenethylamide derivative named N-(p-hydroxyphenethyl)pentacosanamide (1), and a kauranoid derivative named derivative named ent-7-oxo-16α,17-dihydroxykauran-19-oic acid (2), as well as fou...

(S)-5-Phenylmorpholin-2-one dagger and a range of aliphatic aldehydes form chiral iminium. intermediates which undergo diastereoselective Mannich reactions with 2-furylboronic acid, Single crystal X-ray analysis of methylated derivative 4 derived from. major adduct 2g confirms the stereochemical course of the reaction.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The regioselective C-3-O-acylation and O-methylation of a range of 4,6-O-benzylidene-β-d-gluco- and galactopyranosides has been studied. Regioselectivity is achieved by forming the copper chelate of the 2,3-diol using either sodium hydride and copper(II) chloride, or copper(II) acetylacetanoate, or copper(II) acetate, prior to introduction of the a...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.