Solution and single crystal raman spectra of potassium hexacyanochromate(III)

Some inconsistency has existed in the assignment of the vibrational spectra of the Cr(CN)₆^3? ion, and the crystal structure of K₃Cr(CN)₆ has been described both as monoclinic C_2h⁵ and as orthorhombic D_2h¹⁴. The solution and single crystal Raman spectra were recorded at room temperature. On the basis of these data a new assignment was made and the crystal structure was determined to be orthorhombic.     

Cobalt(III)-Gemischtligandenkomplexe mit Phenanthrolin und Picolinsäure. Darstellung,Charakterisierung und einige photochemische Eigenschaften

Mixed-Ligand Complexes of Cobalt(III) with Phenanthroline and Picolinate. Preparation, Characterization, and Some Photochemical Properties Three new cobalt(III) complexes, Co(phen)₂pic²⁺, trans(N)? Co(pic)₂phen⁺, and trans(O)? Co(pic)₂phen⁺ (phen-1, 10-phenanthroline, pic-picolinate), have been isolated and characterized by ¹H-NMR and UV-VIS spectra. Some preliminary data concerning biacetyl-sensitized photochemical decomposition of these complexes in aqueous solutions are reported.     

Identification of phosphate anions in niobium and tantalum phosphates by means of infra-red spectra

Some niobium and tantalum phosphates have been prepared and their infra-red spectra have been recorded and compared with those of reference substances. It has been possible to identify P0₄^-3, P₂O₇^-4 and possibly P₃O10^-5 groups in different samples of niobium and tantalum phosphates.     

Die IR-Spektren einiger Doppeloxide des Typs MIISnO3

I.R. Spectra of Some Double Oxides of the Type M^IISnO₃ The double oxides MnSnO₃, CaSnO₃, and CdSnO₃, which crystallize in the ilmenite lattice as well as the perovskite modification of the two last mentioned compounds have been prepared and characterized by means of their infrared spectra. The spectra were interpreted and discussed in relation to the crystal structures and by comparison with those of related phases.     

Hexamminmetall(III)-hexachlorochromate(III): Darstellung,Kristallgitter und Spektren

Hexammine-metal(III) hexachlorochromates(III). Preparation, crystal lattic and spectra The preparation of [Me(NH₃)₆]CrCl₆ with Me = Co and Rh from aqueous solutions and with Me = Co, Cr and Rh by thermal dehydratation is given. The crystal structure of these compounds is T_h⁶? Pa3, Z = 4. The absorption spectrum shows the two known spin allowed bands at 13300 and 1890C cm^?1. Some weak vibronic absorptions are observed from 13870 cm^?1 to 15130 cm^?1. The vibrational spectrum of CrCl₆^2? has been completed by the measurement of the RAMAN spectrum, the IR spectra have been reinvestigated. The vibrational spectra confirm the nearly undisturbed octahedral symmetry of the hexahalogenometallate anion which has previously been observed for similar compounds.     

Microwave spectrum and structure of equatorial chlorocyclohexane

The microwave rotational spectra of C₆H₁₁³⁵Cl and C₆H₁₁³⁷Cl have been measured. The rotational constants A, B and C and quadrupole coupling constants were determined. Some structural information was obtained.     

n,π* Fluorescence from selected vibronic levels of pyrimidine-d4 vapour: franck-condon factors,ground and excited state anharmonic coupling

Some “single vibronic level” fluorescence spectra of pyrimidine-d₄ are reported. The progression forming modes are ν″_6a (659 cm⁻¹) and ν″₁₂ (1048 cm⁻¹) and in contrast to pyrimidine-d₀ excitation of up to 7 quanta may be clearly identified. The ground-state Fermi resonance between ν_6a1 and 2ν_16b2, so significant in the fluorescence spectra of pyrimidine-d₀, is absent for pyrimidine-d₄. Analyses of the spectra have enabled comparable studies of Franck-Condon factors and Fermi resonances to be carried out. They have provided confirmation of vibrational assignments and have provided the underlying reason for the much sharper and more discrete nature of the pyrimidine-d₄ spectra.     

NMR studies of viomycin

The ¹H and ¹³C NMR spectra of antibiotic Viomycin sulphate and its constituent aminoacids in H₂O and D₂O were examined in a wide range of pH values. The spectra were analysed by proton spin-spin decoupling experiments and measurements of the relative intensities of the resonance and chemical shift values. Exchange experiments were also carried out and an almost complete assignment of the resonances of the spectra was possible. The data obtained are discussed in terms of possible structures for Viomycin and the presence of intramolecular hydrogen bonds. Some information about the conformation of the molecule is also given. A tentative assignment of the ¹³C spectrum of Viomycin is given and the experimental ¹³C chemical shift values compare well with the theoretical ones evaluated by Grant's rule.     

Schwingungsspektren und Kraftkonstanten verschiedener Phosphan-Borane

Vibrational Spectra and Force-Constants of Some Phosphine-Boranes The IR und Raman spectra of Ph₃P? BH₃, Ph₃P? BD₃, and (C₆D₅)₃P? BH₃ were recorded. A normal-coordinate analysis has been carried out, using a simplified model of the phenyl group. With the aid of published spectra, a vibrational analysis of F₃PBH₃ and H₃PBH₃ has been performed, using ¹⁰B—¹¹B-isotopic-shift data. A linear relationship between the ³¹P—¹¹B-N.M.R. coupling constant and the PB-valence-force constant has been found.     

Investigation of some pentasubstituted 1,4-dihydropyridines by means of fast ion bombardment,chemical ionization and electron impact mass spectrometry

Positive fast ion bombardment, positive chemical ionization (CI⁺) and positive electron impact (EI) ionization mass spectrometry were used to investigate a number of relatively large and structurally related organic molecules. Some of the major dissociation pathways observed in the CH₄-CI⁺ mass spectra are not present under NH₃-CI⁺ conditions, but are obtained in the collision-induced dissociation (CID) spectrum of the 50 eV MH⁺ molecular ion, formed in the latter reaction. The resemblance between the EI mass spectra and their fast ion bombardment counterparts, the effect of changing the energy of the bombarding Cs⁺ ion beam over the range 2–16 keV and the different degrees of internal excitation of ions formed in different CI reagent gases are discussed.     

Vibrational and electronic spectra of copper(II) chromate

The infrared, Raman and electronic (reflectance) spectra of CuCrO₄ were recorded. The internal vibrations of the CrO²⁻₄ ions were assigned with the aid of a factor group analysis. The ‘d-d’ transitions of the Cu^IIO₆ moieties and one of the O → Cu charge transfer bands could also be assigned. Some comparisons with other structurally related compounds are made.     

Synthesis and analytical characterization of novel pyridyl‐substituted 1,1′‐ethenedithiolato complexes

Some 1,1′‐ethenedithiolato complexes of nickel(II), palladium(II), and platinum(II) with different phosphine ligands, such as PPh₃, PEt₃, and dppe were prepared. Starting from 2‐, 3‐ as well as 4‐pyridyl methyl ketone, the complexes 1–15 were obtained in an one‐pot synthesis through reaction with carbon disulfide, using potassium‐tert‐butylate as a base. They were characterized by ¹H, ¹³C, and ³¹P NMR, mass spectra, infrared spectra, and UV–VIS spectra. The molecular structures of the (Ph₃P)₂Pd^II complex 9 containing the 3‐pyridyl‐ethenedithiolato ligand and of the (Et₃P)₂Pt^II complex 12 containing the 4‐pyridyl‐ethenedithiolato ligand were determined. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:369–378, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20103     

IR-Spektren einiger Doppeloxide des Typs Te3MIVO8

I.R. Spectra of Some Double Oxides of the Type Te₃M^IVO₈ The infrared spectra of the phases Te₃M^IVO₈ (M^IV = Ti, Zr, Hf, Sn), structurally related to fluorite, have been recorded and discussed. It is shown that all the observed have a complex origin, and it is not possible to assign them to definite vibrations of the metal-oxygen polyhedra present in the lattices.     

Elektronenstoß-induzierte Fragmentierung von 1,2,3,-Thiadiazolen

The mass spectra of some alkyl-,aryl-, acyl-and aroyl-substituted 1,2,3-thiadiazoles and ofbenzothiadiazole are reported and interpreted. After the elimination of N₂ from the molecular ion a rearrangement of the [M—N₂]⁺.-ion occurs producing a thioketenion-radical. Some of the subsequent fragmentation processes demand this structure. Additionally expulsion of S and ·SH respectively from the non-rearranged [M—N₂]⁺.-ion is discussed.     

Fluxional behaviour of π-bonded acetylenes

Some cationic five coordinate complexes of formula [Os(CO)(NO)L₂A]PF₆ (L = tertiary phosphine, A = an acetylene) have been prepared by reaction of the appropriate acetylene with [Os(CO)(NO)L₂(acetone)]PF₆; the variable temperature ¹H NMR spectra of some of these indicate that the coordinated π-acetylene undergoes fluxional behaviour.     

FT‐IR Study of Some Carotenoids

Some natural and semisynthetic carotenoids were examined by means of FT‐IR spectroscopy. The IR bands of the characteristic functional groups (CH₃, CH₂, CC, CO, OH, etc.) were assigned when possible. Some special functional groups – without H‐atoms – such as CCC, ‘cross epoxides', etc., which cannot be easily identified by ¹H‐NMR methods, were also detected in the FT‐IR spectra.     

Some new unsymmetrical diimino tetradentate schiff base derived from 3,4-Diaminobenzophenone: Synthesis, characterization and the formation constant of Ni(II) and Cu(II) complexes

Some new unsymmetrical diimino tetradentate Schiff bases derived from 3,4-diaminobenzophenone, (N-salicyliden-N′-5- OMe.salycyliden)-3,4-diaminobenzophenone (H₂sal-5-OMe.sal.dabp) (H₂L¹), (H₂sal-5-Br.sal.dabp) (H₂L²), (H₂sal-5-Cl.sal.dabp) (H₂L³) and (H₂sal-5-NO₂.sal.dabp) (H₂L⁴) and their Ni(II) and Cu(II) complexes were synthesized and characterized by elemental analysis, IR, ¹H NMR, UV-Vis spectra and mass spectra. The thermodynamic formation constants of the complexes were determined spectrophotometrically at constant ionic strength (0.1 M NaClO₄) at 25 °C in DMF and their free energies of formation were calculated at 25 °C.     

Thiocarboxylato Complexes of Biscyclopentadienyl and Bisindenyl Titanium (IV)

Reactions of biscyclopentadienyl (and bisindenyl) titanium (IV) dichlorides with sodium salts of various thiocarboxylic acids in tetrahydrofuran medium, yield the complexes of the general formula (D) ²Ti(SCOR) ² where D is cyclopentadienyl or indenyl group and R? H, CH₃, C₂H₅, C⁴H⁵ or p-C⁴H⁴CH³ group. The foul smelling complexes are monomeric in nature. The IR spectra, thermal stabilities and Some physical characteristics of these complexes have been studied.     

Vibrational spectra and structure of cis- and trans-1,2- dimethoxyethylenes

The vapor, liquid and CCl₄ solution infrared spectra of cis- and trans-1,2-dimethoxyethylene were recorded in the region 250–4000 cm^?1. The laser-Raman spectra were obtained in the liquid state only. The vibrational spectra show that at least two rotational isomers exist for each molecule. Further, the spectra indicate that for both the cis- and trans molecules, one of the rotational isomers has at least one planar conformer. Some vibrational assignments are made for the observed infrared and Raman bands of the cis- and trans- 1,2-dimethoxyethylenes.     

Synthesis of La(III), Y(III) complexes with polyglycol aldehyde-amino acid Schiff base and their high resolution solid state13C NMR spectra

La (III), Y(III) complexes wit11 diglycol aldehyde his-arginine (H₂DAAR) and tetraglycol aldehyde bislysine (H₂TALY) Schiff bases were synthesized. Thcy were characterized and formulated as La (H₂DAAR) (NO₃)₃. 6H₂0 and Y (H₂TALY) (NO₃)₃. 5H₂0 separately by elemental analyses. The obtained complexes were investigated in detail by high resolution solid state (HRSS)¹³C NMR using cross polarization, magic angle spinning (CPMAS). and total suppression of sidebands (TOSS) techniques. The results are supported by the liquid state 2D-’H-¹³C COSY NMR spectra. Some new information about the splitting peaks of¹³C for -CH = N- group and alkene carbon bands, etc. in HRSS¹³C NMR spectra are given.