FT-IR Photoacoustic Spectra of Gaseous Group VIB Metal Chalcocarbonyl Complexes

1986 ◽  
Vol 40 (7) ◽  
pp. 1004-1009 ◽  
Author(s):  
Zhen H. Xu ◽  
Ian S. Butler ◽  
Francois G. T. St.-Germain

Attempts to record the room-temperature, FT-IR photoacoustic (PA) spectra of the crystalline group VIB metal chalcocarbonyls, M(CO)6 (M = Cr, Mo, W) and Cr(CO)5(CS), suprisingly failed owing to the high volatilities of the solid complexes in the PA cell, and excellent-quality gas-phase spectra were obtained instead. Vibrational assignments are proposed for these gases for the CO stretching and MCO bending fundamentals, and the associated binary overtone and combination spectra in the 4500–500 cm−1 region. The binary overtone and combination spectra are easily observed in the FT-IR/PA spectra and are useful in distinguishing between the four metal chalcocarbonyl complexes.

1987 ◽  
Vol 41 (1) ◽  
pp. 149-153 ◽  
Author(s):  
Ian S. Butler ◽  
Zhen H. Xu ◽  
Rita S. Werbowyj ◽  
Francois St.-Germain

FT-IR photoacoustic spectra have been measured at room temperature in the near- and mid-IR range (4700–500 cm−1) for the solid organometallic compounds: CpM(CO)3 (Cp = η5-C5H5; M = Mn, Re); CpMn(CO)2(CS); [CpFe(CO)2]2; [CpMo(CO)3]2; BzCr(CO)3 (Bz = η6-C6H6); BzCr(CO)2(CS); M2(CO)10 (M = Mn, Re); and Fe2(CO)9. Vibrational assignments have been made for the fundamentals and the binary overtone and combination regions. It is much simpler to obtain data for the 4700–3500 cm−1 near-IR region with the use of PA rather than transmission IR spectroscopy with alkali halide disks since there are no problems with scattering or internal multiple reflectance. FT-IR photoacoustic spectroscopy is a convenient, nondestructive analytical method that should prove extremely useful to organometallic chemists for the rapid identification of their compounds in the solid state.


1992 ◽  
Vol 46 (11) ◽  
pp. 1605-1607 ◽  
Author(s):  
Ian S. Butler ◽  
Denis F. R. Gilson ◽  
Dominique Lafleur

Gas-phase IR photoacoustic (PA) spectra have been obtained for the volatile, solid pentacarbonyl(methyl)metal(I) complexes, CH3Mn(CO)5 and CH3Re(CO)5. The gaseous samples were apparently produced directly in the PA sample cup as the result of local surface heating effects. Vibrational assignments are given for the gas-phase spectra, especially for the binary v(CO) overtone and combinations which absorb in the near-IR region at ∼4000 cm−1. The data provide further support for near-IR/PA spectroscopy being a useful technique for the rapid, nondestructive identification of small amounts of organometallic carbonyl complexes.


2006 ◽  
Vol 6 (1) ◽  
pp. 1275-1299
Author(s):  
T. J. Johnson ◽  
T. Masiello ◽  
S. W. Sharpe

Abstract. Diiodomethane (CH2I2) photolysis in the presence of ozone is a suggested precursor to new particle aerosol formation, particularly in coastal areas. As part of the PNNL database of gas-phase infrared spectra, the quantitative absorption spectrum of CH2I2 has been acquired at 0.1 cm−1 resolution. Two strong b2 symmetry A-type bands at 584 and 1114 cm−1 are observed, but are not resolved at 760 Torr and appear as B-type. In contrast, the b1 symmetry C-type bands near 5953, 4426 and 3073 cm−1 are resolved with rotational structure, including Q-branches with widths ≤1 cm−1. The quantitative infrared and near-infrared vapor-phase spectra (600–10 000 cm−1) are reported for the first time and discussed in terms of atmospheric monitoring. FT-Raman spectra and ab initio calculations are used to complete vibrational assignments in the C2v point group.


Author(s):  
Anastasia Filtschew ◽  
Pablo Beato ◽  
Søren Birk Rasmussen ◽  
Christian Hess

The role of platinum on the room temperature NOx storage mechanism and the NOx desorption behavior of ceria was investigated by combining online FT-IR gas-phase analysis with in situ Raman...


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Scott J. Kirkby

Chlorobenzene was reacted with NO2, in the initially acid-free zeolite NaZSM-5, to yield para-chloronitrobenzene exclusively. The precursors were loaded sequentially into self-supporting pellets of the zeolite, contained within a stainless steel cell, from the gas phase. The reaction proceeds spontaneously at room temperature. It is, however, very temperature dependent and effectively ceases at zero degrees Celsius. The reaction was monitored in situ using FT-IR. The active nitrating agent is formed from the partial electron donation by the NO2 to the Na+ cations present in the zeolite lattice. Under the reaction conditions, chlorobenzene is not readily mobile through the pore system; thus, only the molecules adsorbed near a cation site react to form para-chloronitrobenzene.


1993 ◽  
Vol 47 (2) ◽  
pp. 218-221 ◽  
Author(s):  
Hongqi Li ◽  
Ian S. Butler

Solid-state mid- and near-IR photoacoustic (PA) spectra have been measured at room temperature for the group 6B metal(0) mixed carbonyl- t-butylisocyanide complexes M(CO)6- n(CN tBu) n ( M = Cr, Mo, W; n = 1-3). Vibrational assignments are proposed for many of the observed bands. The PA spectra in the near-IR region (4600-3600 cm−1), where the binary v(CN) and v(CO) overtones and combinations absorb, are useful spectral fingerprints for these organometallic complexes.


2006 ◽  
Vol 6 (9) ◽  
pp. 2581-2591 ◽  
Author(s):  
T. J. Johnson ◽  
T. Masiello ◽  
S. W. Sharpe

Abstract. Diiodomethane (CH2I2) has recently become a molecule of significant atmospheric interest as it can contribute to coastal IO formation. As part of the PNNL database of gas-phase infrared spectra, the quantitative absorption spectrum of CH2I2 has been acquired at 0.1 cm-1 resolution. Two strong b2 symmetry A-type bands at 584 and 1114 cm-1 are observed, but are not resolved when broadened to 760 Torr with nitrogen and appear as B-type. In contrast, the b1 symmetry C-type bands near 5953, 4426 and 3073 cm-1 are resolved with rotational structure, including Q-branches with widths ≤1 cm-1. The quantitative infrared and near-infrared vapor-phase spectra (600–10 000 cm-1) are reported for the first time. Some bands are discussed in terms of their potential for atmospheric monitoring and theoretical detection limits on a selected basis. FT-Raman spectra and ab initio calculations are used to complete vibrational assignments in the C2v point group.


1992 ◽  
Vol 46 (12) ◽  
pp. 1785-1789 ◽  
Author(s):  
Hongqi Li ◽  
Ian S. Butler

Mid- and near-IR photoacoustic (PA) spectra have been measured at room temperature for two series of crystalline manganese(I) carbonyl halides: Mn(CO)5 X and [Mn(CO)4 X]2 ( X = Cl, Br, I). Vibrational assignments are proposed for many of the observed bands. The PA spectra in the near-IR region (4200-3800 cm−1), where the binvary v(CO) overtones and combinations absorb, are useful spectral fingerprints for these organomanganese(I) complexes.


SynOpen ◽  
2021 ◽  
Author(s):  
Mina Ghassemi ◽  
Ali Maleki

Copper ferrite (CuFe2O4) magnetic nanoparticles (MNPs) were synthesized via thermal decomposition method and applied as a reusable and green catalyst in the synthesis of functionalized 4H-pyran derivatives using malononitrile, an aromatic aldehyde and a β-ketoester in ethanol at room temperature. Then it was characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) analysis, scanning electron microscopy (SEM) images, thermo gravimetric and differential thermo gravimetric (TGA/DTG) analysis. The catalyst was recovered from the reaction mixture by applying an external magnet and decanting the mixture. Recycled catalyst was reused for several times without significant loss in its activity. Running the one-pot three-component reaction at room temperature, no use of eternal energy source and using a green solvent provide benign, mild, and environmentally friendly reaction conditions; as well, ease of catalyst recovering, catalyst recyclability, no use of column chromatography and good to excellent yields are extra advantages of this work.


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