Infra-red Spectral Studies Research Articles

Preparation and characterization of plutonium/IV/ phenyl acetate and plutonium/IV/ α-naphthyl acetate

Plutonium/IV/ compounds obtained in the reactions with phenylacetic acid and α-naphthyl acetic acid in the pH range of 3.5–5.0 have been isolated and studied. Carbon, hydrogen and plutonium analyses have shown that plutonium/IV/ phenyl acetate and plutonium/IV/ α-naphthyl acetate have the composition Pu/OH/3/C10H7CH2COO/, respectively. Infra-red and ultra-violet absorption spectral studies and thermogravimetric analysis have corroborated these chemical formulas.

Structure identification of substituted phenol redox products by: thermogravimetric and differential thermal analysis

The structure of separated pure products obtained by oxidation of bromo- and chlorophenols with iodine were investigated by microanalysis, infrared (IR) spectroscopy and by differential thermal analysis (DTA) and thermogravimetric analysis (TGA) to elucidate their molecular formulae. DTA analysis together with the IR spectral studies support the picture developed from TGA. This indicates that not only the crystallization water was lost but also the functional decomposition of these parent halogenated phenols is necessarily needed (as sublimation of some native iodine molecules) to interpret the successive mass lost. This structure elucidation confirms the previously reported mechanism of such redox reactions.

Characterisation of Mixed Ligand Complexes of Cobalt(II) and Nickel(II) with Diphenic Acid As Primary and Heterocyclic Bases as Secondary Ligands

Abstract The mixed ligand complexes of Co(II) and Ni(II) with diphenic acid as primary and quinoline, isoquinoline, pyridine, 8-hydroxy quinoline and 2-amino pyridine as secondary ligands were prepared and characterised on the basis of elemental analysis, conductivity measurements, magnetic, infra-red and electronic spectral studies. The complexes of Co(II) with quinoline and pyridine were octahedral, with 8-hydroxy quinoline and 2-amino pyridine were tetrahedral and with isoquinoline was square planar. The NI(II) complexes were octahedral except for that with isoquinoline which was square planar.

Synthesis and Infra–red Spectral Studies on Some New Phthalein Dyes –Unsymmetrically Substituted Phthalides

2–(m–Nitrobenzoyl) benzoic acid, a γ–keto acid, has been condensed with various phenols to synthesise some novel analogues of phthalein dyes. The products so obtained are unsymmetrically substituted phthalides, ir which the central triphenylmethane carbon is attached tc two different rings. Structures of these new dyes were established by elemental analysis, chemical reactions anc infra–red studies. Their absorption maxima have been determined in ethanol (neutral and alkaline media) and are found to be shifted like those of true phthaleins.

Copolymerization of Vinyl Cinnamate with Vinyl Acetate: Infrared Spectral Studies

Abstract Vinyl cinnamate (C) was synthesized and copolymerized with vinyl acetate (A) in benzene at 60° using benzoyl peroxide as initiator. Monomer distributions in the resulting copolymers were determined by the infrared spectral technique. A calibration curve was obtained for this purpose. Reactivity ratios as calculated by Kelen and Tudos method were found to be rC= 1.401 ± 0.210, rA. = 0.043 ± 0.006.

Chemistry of Organic Eutectics and Molecular Complexes: Naphthalene-Picric Acid and Anthracene-Picric Acid Systems

Abstract Crystallization behavior and nature of complexation have been studied for the naptha-lene-picric acid and anthracene-picric acid systems. Phase diagrams were determined experimentally to get the exact compositions of eutectics and molecular complexes. Data on crystallization velocity obey the relation V = u(ΔT) n where ΔT is undercooling, u and n are constant. Experimental values of heats of fusion do not go in subordination with mixture law. Infra-red and ultraviolet-visible spectral studies indicate the charge transfer interactions in both systems.

Growth, structure and infra-red spectra of CsRP4O12 crystals

CsRP4O12 (where R is a rare-earth ion) crystals have been grown from highly concentrated phosphoric acid solutions. X-ray and infra-red spectral studies were performed on these crystals. Structurally, the CsRP4O12 crystals can be divided into two types: ringtype and chain-type. The crystal chemistry of CsRP4O12 crystals has been briefly discussed and the absorption bands for representatives from each structural modification have been determined.

A Convenient Method for the Synthesis of Alkali Metal Pentafluoromanganates(III)

Abstract Reaction of MnO(OH) and a concentrated solution of AHF2 (A = NH4 +, Na+, K+ or Cs+) in 40% hydrofluoric acid gives instantaneously rose-pink coloured alkali metal pentafluoromanganate(III), A2MnF5 (A = NH4 + or Na+), and alkali metal pentafluoromanganate(III) monohydrate, A2MnF5.H2O (A = K+ or Cs+). Li2MnF5 has been synthesised by reacting lithium carbonate with a solution of MnO (OH) in 40% hydrofluoric acid followed by addition of a small amount of alcohol. Characterisation of the compounds and assignment of molecular structure were made from the elemental analyses, chemical determination of oxidation state of manganese in the compounds, magnetic susceptibility measurements and infra red spectral studies.

X-ray and infra-red spectral studies of CsREP4O12crystals

X-ray and infra-red spectral studies of CsREP₄O₁₂crystals

Growth of fibrous sodium aluminosilicate crystals in silica gel

Following Charnell's method, the synthesis of fibrous sodium aluminosilicate crystals in silica gel is briefly desctibed. Optimum conditions to secure good crystals are discussed. Influence of pH, temperature and concentration of the reactants on the quality, growth rate and number of fibrous crystals is assessed. Different stages of growth are illustrated. Also described are the methods (X-ray powder analysis, electron microprobe analysis and infra-red spectral studies) for identification of synthesized crystals. It is established that the fibrous crystals reported here are a kind of zeolite.

SYNTHESIS AND CHARACTERIZATION OF ANTI-2-FURAN CARBOXALDOXIME COMPLEXES WITH COBALT(II), COPPER(II & I) AND SILVER(I)

Abstract The ligand, 2-furan carboxaldoxime exists in two geometrical isomeric forms: anti-(β-form) and syn-(α-form). Six different complexes of Co(II), Cu(II), Cu(I) and Ag(I) with anti-2-furan carboxaldoxime (FDH) have been prepared and characterized by elemental analysis, molecular weights, conductance studies, magnetic moments and infra-red spectral studies. These are [Co(FDH)4Cl2], [Co(FD)2], [Cu(CH3COO)2 (FDH)]2, [Cu(FD)(OH)]2, Cu(FDH)2 Cl and AgNO3·2FDH. Under the similar conditions, syn- form does not form any complex with these metal ions. The complexes [Co(FDH)4Cl2] and [Co(FD)2] are neutral, monomeric and para-magnetic (μ=4.88 and 4.52 BM respectively); the former may be considered as octahedral with FDH acting as monodentate, and the latter as tetrahedral with FD− as a bidentate ligand. Both the Cu(II) complexes are neutral, dimeric, weakly para-magnetic (μ=0.44 and 0.28 BM respectively) with the bridging acetato groups in [Cu(CH3 COO)2 (FDH)]2 and with bridging hydroxo groups in [Cu(FD)(OH)]2. The Cu(I) complex may be polymeric, being insoluble in most solvents. The Ag(I) compound is cationic 1:1 electrolyte in nitrobenzene. In all these complexes the ligand functions as monodentate and/or bidentate, coordinating with furan oxygen and oxime oxygen in the latter case. The C[sbnd]O[sbnd]C stretching frequency of furan may be taken as the criterion for the denticity of this ligand which is observed at 1240 cm−1 (in the free ligand). A shift to lower frequency is observed in the complex if the ligand acts as bidentate. However this frequency is not affected if the ligand acts as monodentate coordinating through the oxime oxygen atom. The ligand has been shown to be present in the ionized and/or unionized form in these complexes.

Resonance Raman, infra-red, and electronic spectral studies of the μ-oxo-decachlorodimetallate species, [Ru2OCl10]4-and [Re2OCl10]3-, and related ions

Studies of the resonance Raman spectra of the complexes K4[Ru2OCl10] and Cs3[Re2OCl10] have led in each case to the observation of, and identification of, six progressions at room temperature and eight at ca. 80 K, in all of which it is the ν1(a 1g ), symmetric metal-oxygen-metal (MOM) stretching mode which acts as the progression-forming mode. The longest progression in each case is the υ1ν1 one, which reaches υ1 = 12 (Ru) and 14 (Re). The enabling modes are other a 1g fundamentals or combination bands, except for certain cases in which the first and third overtones of infra-red-active fundamentals so act. The ν9(eu ), δ(MOM), mode is particularly effective in this respect, progressions υ1ν1 + 2ν9 and υ1ν1 + 4ν9 reaching to υ1 = 8 and 4 respectively (M = Ru), and 11 and 5 respectively (M = Re). The spectroscopic constants ω1, ω9, x 12, x 13, x 14, x 19, and x 99 have been determined in each case from the data. The symmetry force constant (F 11) associated with MO stretching, 5·60 and 6·84 × 102 N m-1 for Ru and Re respectively, is high and there is extensive mixing of the axial a 1g coordinates. The excitation profiles of all four a 1g fundamentals of each ion maximize near 20 000 cm-1 and, with Raman polarization data, this leads to the conclusion that the resonant electronic transition is an axially polarized π* ←π transition of the M-O-M π-bond system in each case.

ChemInform Abstract: NICKEL(II) COMPLEXES OF ANTI‐2‐FURANCARBOXALDOXIME

AbstractDer Titelligand (I) in der β‐Form reagiert mit NiClz in wasserfreiem EtOH unter Eiskühlung zu dem Komplex (I), der oktaedrisch koordiniert ist, wobei zwischen cis‐ und trans‐Form nicht unterschieden werden kann.

Nickel(II) complexes of anti-2-furancarboxaldoxime

Five different complexes of nickel(II) withanti-2-furancarboxaldoxime (β-FDH) have been prepared and characterized by elemental analysis, molecular weights, conductance studies, magnetic moments and infra-red spectral studies. These are [Ni(FDH)4Cl2], [Ni(FD)2(FDH)], [Ni(FD)2(FDH)2], [Ni(FD)2·en], and [Ni(FD)2]. All the complexes are neutral monomeric, paramagnetic (μ=3.3–3.7 μB) and may be considered octahedral except the complex [Ni(FD)2], (μ=2.92 μB) which is tetrahedral. In these complexes the ligand functions as a monodentate and/or bidentate, coordinating with furan oxygen and oxime oxygen in the latter case. The ligand has been shown to be present in the ionized, and/or unionized form in these complexes.

Infrared Spectral Studies of Metal Chelates of 2-Furan Carboxaldoxime

2-Furan carboxaldoxime (anti-form) or anti-furan 2-aldoxime (FDH) forms octahedral complexes of the type M(FDH)2Cl2 (M = Mn, Co, Ni, Cu and Zn) and M(FDH)3Cl3 (M = Cr and Fe). The infra red spectral studies have revealed that the coordination of the metal involved the oxime oxygen and the furan ring oxygen. However, the ligand acts as bidentate in case of M(FDH)2Cl2 while it is monodentate in M(FDH)3Cl3. The M-O bands in the infrared spectra may be taken as a criterion for the denticity of the ligand in its various metal complexes. Bands at 670-630 cm-1 and around 450 cm-1 indicate the bidentate ligand, while the absence of the band at 670-630 cm-1 reveals monodenticity. The : C=N-stretching frequency has been found to increase with decreasing stability of the bivalent metal complexes, while it is insensitive in case of the trivalent metal complexes.

Raman and Infrared Spectral Studies of Anhydrous Li2CO3 and Na2CO3

The infrared and Raman spectra of anhydrous crystalline Li2CO3 and Na2CO3 were measured at 300 and at 80°K. Bands observed in the vibrational spectra of Li2CO3 were assigned according to the C2h factor group symmetry. The doublet structure observed for each of the internal modes in the spectra of Na2CO3 was interpreted in terms of an ordered arrangement of CO3= ions over two nonequivalent orientations within the primitive cell. Multiple internal reflection and polarized specular reflectance techniques were used to determine transverse optical (TO) and longitudinal optical (LO) mode frequencies in Li2CO3 and Na2CO3. It was shown from these measurements that the infrared transmission spectra of these compounds exhibit band maxima which are admixtures of LO and TO modes.

Studies on molybdenum(VI) o-hydroxyacetophenoneoxime

Ortho-hydroxyacetophenoneoxime reacts instantaneously with molybdenum in acidic media to give a highly-stable, bright yellow, soluble complex. Vosburgh and Cooper's method showed the existence of only one complex in the yellow solution with maximum absorption at 345 mμ. The complex was found to be stable at pH 2.5–5.5. Both Job's method of continued variation and the slope ratio method revealed its composition as 1:2 ( molybdenum: reagent). The stability constant of the complex was determined by Anderson's method and found to be 9.3 × 10 8 and− ΔG°=12.39 kcal/mol at 30°C. The results of chemical analysis of the isolated complex for its nitrogen and molybdenum contents correspond to its molecular formula of (C 8H 8O 2N) 2. MoO 2. The infra-red spectral studies provide evidence that the phenolic hydrogen is replaced by MoO 2 ++ which, in turn, is coordinated to the nitrogen of the oxime (− C= NOH) group to form a chelate compound.

Infrared-spectral Studies on the Orientation of the Lone Pairs in Piperidine Derivatives

Abstract The infrared spectra of stereoisomers of several piperidines and their N-methyl derivatives in carbon tetrachloride have been measured in the region of 3020 to 2500 cm−1. The estimated intensities (A) of their Bohlmann bands have been analyzed, provided that Formula (1) concerning the intensity defined in the text holds for the compounds examined. The result indicates that piperidine exists mainly, but not exclusively, in the conformation with the lone pair axial.

Infrared-spectral studies on the orientation of the lone pairs in piperidine derivatives

Infrared-spectral studies on the orientation of the lone pairs in piperidine derivatives

Infrared-spectral studies on the orientation of the lone pairs in piperidine derivatives

Infrared-spectral studies on the orientation of the lone pairs in piperidine derivatives