Fourier Transform Infrared and Raman Spectra of 4-Vinylpyridine and its Transition Metal(II) Tetracyanonickelate Complexes

Abstract

Infrared and Raman spectra (4000-200 cm^?1) were recorded for 4-vinylpyridine and vibrational assignments made for fundamental modes on the basis of frequency shifts of the coordinated ligand, of the group vibrational concept and comparison with the assignments for related molecules. the infrared spectra of M(4-vinylpyridine)₂Ni(CN)₄ (M=Mn, Cd, Fe, Co, Ni or Cu) are reported.     

FT‐Raman spectroscopic spectra on 3‐phenylpropylamine inclusion compounds

Some new Hofmann‐3‐phenylpropylamine‐type clathrates with chemical formulae of M(3‐phenylpropylamine)₂ Ni(CN)₄. 2G (MNi or Co, G = 1,2‐dichlorobenzene or 1,3‐dichlorobenzene) have been prepared and their Fourier transform infrared(FT‐IR; 4000–400 cm⁻¹), far‐infrared (600–100 cm⁻¹) and FT‐Raman (4000–60 cm⁻¹) spectra are reported. The ligand molecule, guest molecules, polymeric sheet and metal‐ligand bands of the clathrates are assigned in detail. The compounds are also characterized by thermal gravimetric analysis (TGA), differential thermal analysis (DTA), elemental analysis and magnetic susceptibility measurements. From the results, the monodentate 3‐phenylpropylamine ligand molecule bonds to the metal atom of |M‐Ni(CN)₄ | _∞ polymeric layers in the trans‐gauche‐gauche (TGG) form, and 1,2‐dichlorobenzene or 1,3‐dichlorobenzene molecules are guested by this structure revealing the inclusion ability of the host complexes. Copyright © 2010 John Wiley & Sons, Ltd.     

Fourier Transform Infrared and Raman Spectra of Metal Halide Complexes of 3,5-Lutedine in Relation to Their Structures

Abstract

Fourier transform infrared (4000-200 cm¹) and Raman (3500-50 cm^?1) spectra are reported for metal(II) halide 3,5-lutidine (3,5-dimethylpyridine) complexes of the following stoichiometries: M(3,5L)₄X₂ M=Co or Ni, X=C1 or Br; M=Mn or Cu, X=Br; M=Cd, X=I; M(3,5L)₃X₂ M=Fe, X=C1; M=Cu, X=Br; Hg(3,5L) X₂ X=C1 or Br.

Vibrational assignments are given for all the observed bands. Some structure- spectra correlations are found. For a given series of isomorphous complexes the sum of the difference between the liquid and ligand values of the vibrational modes of 3,5-lutidine is found to increase in the order of the second ionization potentials of the metals. The frequency shifts are also found to depend on the halogen.     

The Raman Spectrum of The 3-Br Pyridine-Bromine Charge Transfer Complex

The formation of a charge transfer complex between pyridine and halogens or mixed halogens^(1,2) brings about perturbations in the infrared spectra of the pyridine molecule and many halogen complexes show two bands in the low frequency range, which can be attributed to the v _X-X and v _N…Y stretching vibrations. ^(3–5). However, by comparison, very little has been reported on the Raman spectra of such complexes. Klaboe⁽⁶⁾ studied the v _Br-Br Raman frequency of some bromine complexes and more recently the Raman spectra of pyridine complexed with Ni (CN)₄ ⁽⁷⁾ and TiCl₄ ⁽⁸⁾ have been reported. In this work, the Raman spectrum of the 3-Br pyridine-bromine charge transfer complex is investigated.     

Vibrational Spectroscopic Studies of 3,4-Lutidine Metal (II) Tetracyanonickelate Complexes

Infrared and Raman spectra of seven new metal (II) 3,4-lutidine tetracyanonickelate complexes, M(3,4 L)₂ Ni(CN)₄ [where 3,4 L = 3,4 - dimethyl-pyridine or 3,4-lutidine; M = Mn, Fe, Co, Zn, Ni, Cu or Cd] (abbreviated to M - Ni - 3,4 L) have been investigated. Spectroscopic and magnetic susceptibility measurements indicate that the compounds have the structure of Hofmann-type complexes. The copper complex has spectral features different from the other compounds.     

The Infrared and 1H-NMR Spectra of 8-Hydroxyquinoline Adducts of 8-Hydroxyquinoline Complexes of Dioxouranium(VI), Thorium(IV) and Scandium(III)

The ¹H-nmr and infrared spectra of the complexes [M(ox)_n(Hox)] where M = UO₂ (n = 2), Th (n = 4) or Sc (n = 3) and Hox = 8-hydroxyquinoline are discussed. The nmr spectra of the adducts are uninformative with respect to the bonding and structure of these molecules since they dissociate in solution. The solid state ir spectra show that the adducted molecule of 8-hydroxyquinoline is bound to the metal through the phenolic oxygen, the proton forming an intramolecular hydrogen bond between the nitrogen atom of the adducted molecule and the oxygen atom of a neighbouring chelate ring. The mid-and far-ir spectra are reported for the first time and assignments for the δN-H, νM-O and νM-N modes have been made.     

Synthesis and Spectroscopic Studies of Metal (II) Tetracyanonickelate Complexes with 1,3-Thiazolidine-2-thione

Two new Hofmann-type complexes, M (1,3-thiazolidine-2-thione)₂ Ni(CN)₄ (where M = Ni and Cd), were synthesized and characterized by elemental analysis, magnetic susceptibility data, IR and Raman Spectroscopy. Their structure consist of planar infinite polymeric layers of {M-NI(CN)₄}∞. 1,3-thiazolidine-2-thione coordinated to M atom above and below this layers is monodentate and S-bonded in these complexes.     

Infrared and Raman Spectra of Sulfur-Nitride Complexes of Nickel(II) and Palladium(II)

Abstract

The infrared and Raman spectra of trans-Ni(S₂N₂CH₃)₂ and Pd(S₃N)₂ were measured from 4000-200 cm^?1. The absorption bands were assigned by comparison to the sulfur nitride complexes of nickel(II), palladium(II) and platinum(II). Normal coordinate analyses on these complexes were carried on these data using molecular parameters taken from X-ray data. To aid in band assignments, isotope shift data on trans-⁶²Ni(S₂N₂CH₃)₂ have also been carried out.     

The vibrational spectra of some isotopic species of propionitrile

The infrared and Raman spectra of CH₃CH₂CN, CH₃CD₂CN, and CD₃CH₂CN, and the infrared spectrum of CH₃CH₂¹³CN were investigated in detail between 6000 and 100 cm⁻¹. Some infrared measurements of other isotopic species are also reported and partial assignments given. All fundamentals of propionitrile-d₀, -d₂, -d₃, and -¹³CN were assigned, together with a large number of mainly binary combination bands for which a general method of assignment is given. Several Fermi resonances were detected and the unperturbed positions of some of the levels involved were calculated. Special attention was paid to the CH stretching vibrations for which persisting wrong assignments exist in the literature, and to the methyl torsion frequencies which were determined for the four isotopic species above. A valence force field was calculated, and the potential energy distribution of the normal vibrations is tabulated.     

Infrared Spectroscopic Study of N,N‐Dimethylthioformamide Complexes of the Hofmann Type

Four new Hofmanntype complexes, M(DMTF)₂Ni(CN)₄, (where DMTF is dimethylthioformamide, M=Mn, Cd, Co, or Ni) were synthesized and their structure was determined by an elemental analysis and infrared spectroscopy. The IR spectra of DMTF and its nickel tetracyanine complexes with Mn(II), Cd(II), Co(II), and Ni(II) have been investigated within the range 4000–400 cm^–1. The frequency shifts in the metal complexes agree with the assignment of the CS and CN frequencies. The complexes consist of infinite planar polymer layers of |MNi(CN)₄|. Ndimethylthioformamide is coordinated to this layer from above and below; it is a monodentate ligand and is Sbonded through the metal atom in these complexes.     

Structural Information from the Infrared Spectra of Metal(II) Complexes of Tropolone and 2-Thiotropone

Evidence for polynuclear octahedral coordination in the complexes [MT²]_n (M = Ni, Zn; T = tropolonate anion; n > 1) is adduced by observing the effect of base adduct formation on their infrared spectra. The spectra of the complexes [M(ST)₂] (M = Co, Ni, Cu, Zn; ST = 2-thiotroponate anion) are discussed in relation to their known or probable structures.     

Vibrational Spectroscopic Studies on the Dicyclopropylaminecadmium(II)Tetracyanometallate(II) Benzene Clathrates

ABSTRACT

New Hofmann–T_d-type clathrates of the forms Cd(CPA)₂M(CN)₄.C₆H₆ (CPA = cyclopropylamine; M?Cd or Hg) prepared in powder form and characterized by FT-IR, FT-Raman, far-IR spectra, X-ray diffraction, and elemental analyses are reported. Vibrational assignments are proposed for the bands of the host lattice and guest molecule. It is shown that the spectra are consistent with a proposed crystal structure for the compounds derived from X-ray diffraction measurements. The C, H, and N analyses were carried out for all the compounds. All the vibrational modes of coordinated CPA are characterized. The spectral features suggest that these compounds are similar in structure to the Hofmann–T_d-type clathrates.     

Experimental vibrational spectra (Raman,infrared) and DFT calculations on monomeric and dimeric structures of 2‐ and 6‐bromonicotinic acid

In this work, the Fourier transform infrared and Raman spectra of 2‐bromonicotinic acid and 6‐bromonicotinic acid (abbreviated as 2‐BrNA and 6‐BrNA, C₆H₄BrNO₂) have been recorded in the region 4000–400 and 3500–50 cm⁻¹. The optimum molecular geometry, normal mode wavenumbers, infrared intensities and Raman scattering activities, corresponding vibrational assignments and intermolecular hydrogen bonds were investigated with the help of B3LYP density functional theory (DFT) method using 6‐311++G(d,p) basis set. Reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated with scaled quantum mechanical (SQM) method. From the calculations, the molecules are predicted to exist predominantly as the C1 conformer. Copyright © 2009 John Wiley & Sons, Ltd.     

The Infrared Spectra of the First Transition Series Metal(II) Bis(Aquo) Complexes Of 8-Hydroxyquinoline

Abstract

The infrared spectra (700–100 cm^?1) of the complexes [M(ox)₂(H₂O)₂] (ox = 8-hydroxyquinolinate anion, M = Mn, Fe, Co, Ni, Cu, Zn) are discussed. For the purposes of assignment of the metal ligand modes, deuterated 8-hydroxyquinoline-d ₇ was prepared by the Skraup synthesis and the spectra of the deuterated complexes were compared with those of the unlabelled species. Furthermore, [⁶⁴Zn(ox)₂(H₂O)₂] and [⁶⁸Zn(ox)₂(H₂O)₂] were prepared by reaction of ⁶⁴ZnSO₄ and ⁶⁸ZnSO₄ with 8-hydroxyquinoline and the effects of metal isotope labelling on the spectra were examined and compared with earlier isotopic data on the nickel and zinc complexes.     

Infrared Spectra of the Copper(II), Nickel(II) and Palladium(II) Complexes of 4-amino-3-pentene-2-one

Abstract

The infrared spectra of the metal complexes of 4-amino-3-pentene-2-one were measured from 4000 - 20 cm^?1. The absorption bands were assigned by comparison to other similar molecules: The Cu(II) complex of 4-methylamino-3-pentene-2-one, and complexes of acetylacetone. Force constants for the molecules were calculated using the A_xsm matrix method. The spectra were measured at 298^oK and 77^oK.     

Far Infrared and Raman Spectra of Some Crystalline Iodomercurate Complexes

Abstract

Vibrational spectra of crystalline powders of [Nien₂] [HgI₃]₂ and [Men₂] [HgI₄] (where en = ethylene-diamine chelated to M = Ni(II), Pd(II) or Pt(II)) have been measured at room and liquid-nitrogen temperatures. The bands observed in the low frequency region 200–10 cm^?1 are interpreted in terms of mainly internal vibrations of the anions and external lattice modes. Raman and far infrared spectra are compared in order to make structural deductions. In comparison with present knowledge of the stereochemistry and vibrational spectroscopy of other iodomercurates, the triiodo-mercurate salt seems to contain nearly planar trigonal anions, while the tetraiodomercurates contain discrete tetrahedra. Probable site symmetries of the anions which may explain the spectra are discussed.     

Temperature dependent study of the single crystal electronic spectrum of octahedral Ni2+ ion subjected to distortions in weak fields

Electronic spectra of two high spind ⁸ nickel complexes, Ni(en)₃Cl₂.2H₂O and Ni(OAc)₂.4H₂O, are reported. Polarized spectra were measured at 298 K. Temperature dependent spectra were measured using unpolarized light down to 20 K. The spectra at 20 K are well resolved revealing the features of spin-forbidden transitions and vibrational fine structure on some of the bands. Some of the spectra are deconvoluted to separate out the overlapping bands. The assignments are made usingD ₃ symmetry for Ni(en)₃Cl₂.2H₂O complex whileD ₄ symmetry is used for Ni(OAc)₂.4H₂O. The energies of the spectroscopic states are calculated and compared with the observed transition energies. The distortion parameters are determined.     

Raman spectroscopic study of the uranyl mineral natrouranospinite (Na2,Ca)[(UO2)(AsO4)]2· 5H2O

Raman spectra of natrouranospinite complemented with infrared spectra were studied and related to the structure of the mineral. Observed bands were assigned to the stretching and bending vibrations of (UO₂)²⁺ and (AsO₄)³⁻ units and of water molecules. U O bond lengths in uranyl and O H···O hydrogen bond lengths were calculated from the Raman and infrared spectra. Copyright © 2009 John Wiley & Sons, Ltd.     

Raman Study of the Effect of NaClO4 and NaI on the Hydrogen-Bonded Structure of Liquid NH3

Abstract

Recent studies^1,2 of the Raman spectra of liquid ammonia have been in disagreement with regard to the assignment of bands in the 3000 cm^?1 region. This region is complicated by Fermi resonance between the ν₁ (A₁) fundamental stretching mode and the 2ν₄ (A₁) overtone of the bending mode. In an effort to help clarify these assignments and to study further the structure of liquid ammonia, it was decided to measure the Raman spectrum of several salt solutions in liquid ammonia.     

Molecular structure,spectroscopic (FTIR,FTIR gas phase,FT‐Raman) first‐order hyperpolarizability and HOMO–LUMO analysis of 4‐methoxy‐2‐methyl benzoic acid

Vibrational spectral analysis was carried out for 4‐methoxy‐2‐methyl benzoic acid (4M2MBA) by using Fourier transform infrared (FT‐IR) (solid, gas phase) and FT‐Raman spectroscopy in the range of 400–4000 and 10–3500 cm⁻¹ respectively. The effects of molecular association through O H···O hydrogen bonding have been described by the single dimer structure. The theoretical computational density functional theory (DFT) and Hatree‐Fock (HF) method were performed at 6–311++G(d,p) levels to derive the equilibrium geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities. The scaled theoretical wavenumbers were also shown to be in good agreement with experimental data. The first‐order hyperpolarizability (β₀) of this novel molecular system and related properties (β, α₀ and Δα) of 4M2MBA are calculated using the B3LYP/cc‐pvdz basis set, based on the finite‐field approach. A detailed interpretation of the infrared and Raman spectra of 4M2MBA is reported. The theoretical spectrograms for FT‐IR and FT‐Raman spectra of the title molecule were also constructed and compared with the experimental one. Copyright © 2010 John Wiley & Sons, Ltd.