PMR Studies Research Articles

SYNTHESIS AND CHARACTERIZATION OF SOME METAL COMPLEXES WITH IETS AS LIGAND DERIVED FROM 2-ACETLYLINDAN-1,3-DIONE

The present investigation are based on the synthesis and characterization of metal complexes with Schiff’s bases (anils) α– (1, 3– dioxo– indan– 2–yl) – ethylidene– thiosemicarbazone(IETS) derived from 2-substituted acetyl 1, 3 - dione by condensing it with primary aryl amine (aniline) in absolute alcohol. 2-acetyl indan-1, 3-dione was prepared by claisen-condensation. The Co (II), Ni(II), Cu (II), Zn (II), Cd (II), Fe (III), V (III) and Cr (III) complexes of the Schiff’s bases have been prepared in the reactions and investigated their structures by physicochemical methods. The formulation and structure of the ligands have been screened by their chemical analysis, IR, PMR and mass-spectral studies. The PMR spectrum of the metal complexes in quite similar to the PMR spectrum of the anil (IETS) with slight change in the position of PMR signals. The metal complexes are thermally stable at higher temperature (̴ 300o). These characteristics suggest polymeric nature of the metal complexes. The observed molar conductance values of the complexes with IETS have been found in the range 170 to 250 mhos cm2g mol-1. The mass-spectra of this IETS showed the molecular ion peak as a base peak at m/z 261. The structure of ligand has been confirmed by their mass–spectral studies. Keywords: Metal Complexes, Schiff’s bases, 2-Acetlylindan-1,3-Dione

ChemInform Abstract: Preparation of Oxazolidin-2-ones by Oxidation of Oxazolidine-2-thiones. A Proton Magnetic Resonance Structural Study.

The preparation of a series of oxazolidine-2-thiones, both homochiral and racemic, as well as their oxidation to oxazolidin-2-ones is reported. X-Ray and pmr studies have showed that the stereochemical integrity of the starting aminoalcohol is maintained.

Synthesis, characterization and biological studies of CoII, NiII, CuII and ZnII complexes of Schiff bases derived from 4-substituted carbostyrils[quinolin2(1H)-ones

Schiff bases derived from 4-aminomethylcarbostyril and their transition metal complexes with CoII, NiII, CuII and ZnII have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibilities electronic, IR, PMR, ESR, FAB-Mass and thermal studies. From the above spectral studies it is concluded that the ligands of 4-substituted carbostyril Schiff bases, viz, salicylidene 4-aminomethylcarbostyril (SAMC); o-vanillinsalicylidene 4-aminomethylcarbostyril (VAMC) and 5′ chlorosalicylidene 4-aminomethylcarbostyril (CSAMC) act as bidenate molecules coordinating through azomethine nitrogen and phenolic oxygen. The ligands and their metal complexes have been screened in vitro for antibacterial, antifungal and antitumor activity. The results indicate that the biological activity increases on complexation. The CuII complexes of the above ligands show greater inhibitory action towards the P388/s tumor cells at lower concentrations.

Piperidone derivative from Dalbergia sympathetica

An alcoholic extract of Dalbergia sympathetica, on column chromatography, yielded a compound which analyzed for C(6)H(11)NO(3) (M(+) 145). The IR spectrum of the compound showed the presence of carbonyl and hydroxyl groups. PMR, (13)C and DEPT NMR spectral studies of the compound showed the presence of one N-methyl, two methine and two methylene groups. A quaternary carbon signal at delta 172.88 ppm was assigned to C-2 carbonyl of the compound. From all the above observations and also from the HMQC 2D NMR spectrum, the compound was identified as 3, 6-dihydroxy-N-methyl-2-piperidone. This is the first report of the natural occurrence of this compound from plant sources.

A cohort study of mortality among Ontario pipe trades workers

Aims: To study mortality in a cohort of members of the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada...

Physicochemical studies on uranium(VI) complexes of N ,N-dialkylamides

Uranyl dinitrate complexes UO 2 (NO 3 ) 2 .2L with two N,N-dialkylamides, viz. N,N-dihexyloctanamide (L 1 ) and N,N-dihexyldecanamide (L 2 ) have been synthesized. IR spectra reveal that the amide molecules are O-bonded to U and both the nitrate ions act as bidentate groups. Visible spectra indicate the formation of a monedeatate inner-sphere metal-amide complex. PMR spectra of the complexes indicate the pressace of restricted rotation around the C-N bond. The variable temperature PMR studies suggest a dynamic equilibrium beteen the coordinated and free amide melecules Thermal investigations reveal that decomposition proceeds in three TG stages with four exothermic DTA steps correspending to the release of two molecules of amides and two mitrato groups, finally leading to U 3 O 8 .

A study of the anodic behaviour of ruthenium by potential modulated reflectance spectroscopy

Potential modulated reflectance spectroscopy (PMRS) has been used to study the anodic oxidation of ruthenium. Although the cyclic voltammograms of ruthenium in alkaline solutions are broad and relatively featureless, PMRS allows identification of soluble RuO 4 2− (Ru(VI)) and RuO 4 − (Ru(VII)) species formed at the onset of oxygen evolution. The PMR spectra exhibit an isosbestic point that is attributed to the RuO 4 2−/RuO 4 − redox couple. The peaks in the PMR spectra correlate well with reported λ max values of RuO 4 2− at 470 nm and RuO 4 − at 385 and 315 nm. The PMR spectra can be fitted to a difference spectrum calculated from the absorption spectra of the two species. PMR studies of ruthenium dissolution in acid solutions indicate that RuO 4 is the only identifiable corrosion product formed in the oxygen evolution region in this case.

SYNTHESES OF 1,5-BENZOTHIAZEPINES, PART XVI: SYNTHESES OF 8-ETHOXY/FLUORO-2-CABOXY-4-(FLUORINATED ARYL) -2,3-DIHYDRO-1,5-BENZOTHIAZEPINESAS PROSPECTIVE CARDIOVASCULAR AGENTS

Syntheses of fluorinated 8-ethoxy/fluoro-2-carboxy-4-substituted ary-2,3-dihydro1,5-benzothiazepines having substitutents as chloro, methyl and trifluoromethyl have been achieved by the reaction of 5-ethoxy/-fluoro-2-aminobenzenethiols with fluorinated 3-substituted benzoyl-2-propenoic acids in toluene with catalytic amount of trifluoroacetic acid. The progress of the reactions was monitored by t.1.c. studies. Structures of the title compounds are established by IR, PMR and mass spectral studies and microestimation data of nitrogen.

Conformational Analysis of 3′-Deoxy-β-D-Ribonucleosides Using 1D-noe Difference Spectroscopy

The results of PMR studies on 3′-deoxy-β-D-ribonucleosides (1a-d) reveals that the sugar puckering is predominantly in N state with g+ conformation of the 5′-CH2OH group. Except in 1a, nucleobases in other nucleosides favour anti conformation. An preliminary version of this manuscript was inadvertently sent to the publisher, apearing volume 15, issue 10, pp. 1595-1601, 1996. This paper is the final, accepted version of the manuscript.

Preparation of oxazolidin‐2‐ones by oxidation of oxazolidine‐2‐thiones. A proton magnetic resonance structural study

AbstractThe preparation of a series of oxazolidine‐2‐thiones, both homochiral and racemic, as well as their oxidation to oxazolidin‐2‐ones is reported. X‐Ray and pmr studies have showed that the stereochemical integrity of the starting aminoalcohol is maintained.

IR, PMR and TG Studies on Substituted 1,3,5-Triphenylformazans Complexes with Bivalent Cobalt, Nickel, Copper and Zinc

IR, PMR and TG Studies on Substituted 1,3,5-Triphenylformazans Complexes with Bivalent Cobalt, Nickel, Copper and Zinc

Azine Derivatives of 5,5′-Dithiobis(salicylaldehyde) and Their Organoxytitanium(IV) and Organotin(IV) Complexes

Abstract 5,5′-Dithiobis(salicylaldehyde) reacts with salicylaldehyde hydrazone or 2-hydroxyacetophenone hydrazone forming new dithiobis(diazine) derivatives containing four OH, two N-N and one S-S groups. The products have been characterized by elemental analyses, IR, PMR and mass spectral studies. These dithiobis(diazines) react with titanium tetrachloride and tetraisopropyl titanate forming chelated dichloro- and diisopropoxytitanium complexes. These titanium compounds are non-melting solids, sparingly soluble in common organic solvents except alcohols. Similarly, new stable organotin complexes are prepared by reacting these ligands with dibutyltin oxide or triphenyltin hydroxide. The tin compounds are sharp melting and show good solubility in organic solvents.

Semi-synthetic antibiotics: Titanium(IV), zirconium(IV) and mercury(II) complexes of 6-amino penicillinic acid

A number of organometallic derivatives involving 6-amino penicillinic acid ( I), of the types η 5-R) 2M- (Cl)L −Et 3NH + ( II), (η 5-R) 2M(Cl)L ( III) and R′HgL [R = cyclopentadienyl (C 5H 5), indenyl (C 9H 7), R′ = phenyl (C 6H 5), p-acetoxyphenyl ( p-CH 3COOC 6H 4), o-hydroxyphenyl ( o-HOC 6H 4), p-hydroxyphenyl ( p-HOC 6H 4); M = Ti(IV), Zr(IV); LH = 6-amino penicillinic acid] have been synthesized and characterized. Conductance measurements indicate that while the (η 5-R) 2M(Cl)L −Et 3NH + complexes are 1:1 electrolytes, the remaining compounds are non-electrolytes. From IR and UV spectral studies it is concluded that the penicillin moiety is bidentate. PMR and CMR studies support the stoichiometry of the complexes. Fluorescence studies have been carried out for o- and p-HOC 6H 4HgL complexes and relevant photochemical parameters have been elucidated. X-ray diffraction studies have been made for the o-HOC 6H 4HgL complex. For the C 6H 5HgL, p-CH 3COOC 6H 4HgL and p-HOC 6H 4HgL complexes, thermal studies (TG and DTA) have been carried out and kinetic parameters for thermal degradation have been enumerated. In addition, the fragmentation pattern of these complexes has been analysed on the basis of mass spectra. The C 6H 5HgL and p-CH 3COOC 6H 4HgL complexes show positive bactericidal activities.

PMR studies based on lanthanoid shift reagents: Aurone and thioaurone steric structures

The proton resonance spectra have been used along with the interactions with the lanthanoid shift reagent tris-1,1,1,2,2,3,3-heptofluoro-7,7-dimethyloctane-2,6-dione-Eu(III) to establish the isomeric forms and preferred conformations of substituted aurones and thioaurones. Calculations have been performed on the geometrical structures of the LSR-substrate adducts for certain compounds.

The inhibition of erythrocyte glyceraldehyde-3-phosphate dehydrogenase in situ PMR studies

The kinetics of inhibition of human erythrocyte glyceraldehyde-3-phosphate dehydrogenase by iodoacetate were studied in the intact cell and in vitro. The kinetics were determined using 1H-NMR to follow solvent exchange of 1H and 2H at the C-2 position of lactate. The exchange occurs via a series of enzyme-catalysed reactions, including that catalysed by glyceraldehyde-3-phosphate dehydrogenase. A direct assay with quenching of the inhibition was also used to check the results. Iodoacetate was shown to act as an active site-directed inhibitor of the dehydrogenase. The enzyme inhibition patterns, which are characterised by a binding step and a kinetic step, are similar in situ and in vitro. Membrane binding, however, was found to alter the inhibition pattern for the enzyme in vitro.

Structural determinations of some chloroazepine‐2,5‐diones using a lanthanide shift reagent

AbstractThe use of a lanthanide shift reagent, Eu(fod)3, to aid in the structural assignments of some chloroazepine‐2,5‐diones is described. The chloroazepine‐2,5‐diones, synthesized via the Schmidt reactions of chloro‐1,4‐benzoquinones, could not readily have their structures assigned by other spectroscopic methods. Correlations of plotted lanthanide induced shifts in pmr studies demonstrated that there was a large positional dependence on the magnitude of induced shifts. The large difference in the magnitude of induced shifts made it possible to assign protons and methyl substituents to specific positions on the azepine ring, thus assigning the structure of the compound.

Structural studies on a human bladder stone — PMR and IR studies

Wide line Proton Magnetic Resonance spectra of a human urinary bladder stone powder at several temperatures (in the range 77 K to 298 K) and its IR spectra (at 77 K and 298 K) were recorded and analysed. The PMR spectrum at 77 K was a broad signal and at 143 K it exhibited two signals, one broad and one narrow superimposed on each other. The line width of the broad signal and its second moment value remained constant up to 298 K and this signal was identified as due to the protons of water molecules in the sample. The narrow signal was attributed to the protons of NH4 group in the sample and reduction in the value of its second moment at higher temperatures has been interpreted as due to the hindered rotation of NH4 group. The IR spectrum at 77 K has shown the presence of O−H... O bonds in the sample.

The Complex formation of cadmium(II) and mercury(II) with aliphatic dipeptides

Stability constants for complexes between cadmium(II) and mercury(II) and a series of dipeptides consisting of glycine, alanine, leucine and proline have been determined by the pH-titration method. Influences of the side chains on the stability of the complexes are discussed. Cadmium(II) forms 1:1 complexes of the type CdLH + (LH 2 = H 3 N + CHRCONHCHR′COO −, as well as 1:2 complexes of the type CdL 2H 2. Mercury(II) also forms 1:1 complexes of the type HgLH +; there is, however, only a small tendency for the formation of HgL 2H 2. Possible structures are postulated according to the results of PMR studies on glycylglycine in water in the presence of CdCl 2. The PMR spectra suggest that complex species of the type CdLH 2+ 2 may exist; difficult to detect by the pH-titration method. The complex formation of cadmium(II) is compared with that of mercury(II).

ChemInform Abstract: PMR AND UV‐VIS SPECTROSCOPIC STUDIES ON STRUCTURE OF SOME N‐VINYLCARBAZOLES

Chemischer InformationsdienstVolume 12, Issue 34 Physical Organic Chemistry ChemInform Abstract: PMR AND UV-VIS SPECTROSCOPIC STUDIES ON STRUCTURE OF SOME N-VINYLCARBAZOLES J. PIELICHOWSKI, J. PIELICHOWSKISearch for more papers by this authorZ. KOWALCZYK, Z. KOWALCZYKSearch for more papers by this author J. PIELICHOWSKI, J. PIELICHOWSKISearch for more papers by this authorZ. KOWALCZYK, Z. KOWALCZYKSearch for more papers by this author First published: August 25, 1981 https://doi.org/10.1002/chin.198134061AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue34August 25, 1981 RelatedInformation

PMR study of intramolecular motions in solid p-toluidine

Wide-line PMR studies on solid p-toluidine have been made in the temperature range 77–318 K at 7.5 MHz. Analysis of second moment data suggests a rigid and non-rotating state of the crystal lattice at 77 K. The molecular and crystal structure is confirmed. The second moment gradually decreases up to 240 K (a fall of 2.8 G 2) which is indicative of quantum mechanical tunnelling of methyl protons. An observed abrupt fall in p.s.m. beyond 240 K is followed by a phase transition and is attributed to methyl and amino group reorientation upto the melting point. The potential barrier to the reorientation is found to be approximately 8.88 kcal mol −1 in the solid phase.