pinecone/core-2020-05-10-deduplication huggingface dataset:
Raman spectroscopy of the transition of α-gallium oxyhydroxide to β-gallium oxide nanorods

The thermo-Raman spectra of synthesised α-gallium oxyhydroxide nanorods proves the transition of α-gallium oxyhydroxide to β-gallium oxide nanorods occurs above 350 degrees Celsius but below 400 degrees Celsius.  Scanning electron microscopy proves the morphology of the α-gallium oxyhydroxide nanorods is retained upon calcination to β-gallium oxide. X-ray diffraction shows that the nanorods are α-gallium oxyhydroxide converting upon calcination to β-gallium oxide.   \ud
Intense Raman bands are observed at 190, 262, 275, 430, 520, 605 and 695 cm-1 which undergo a red shift of ~5 cm-1 upon heating to 350 degrees Celsius. Upon thermal treatment above 350 degrees Celsius the Raman spectrum shows a significantly different pattern. Raman bands are observed at 155, 212, 280, 430, 570 and 685 cm-1.   The thermoRaman spectra are in harmony with the TG and DTG patterns which show the reaction of α-gallium oxyhydroxide to β-gallium oxide occurs at 365 degrees Celsius
Raman spectroscopic study of the schmiederite Pb2Cu2[(OH)4|SeO3|SeO4]

Raman spectroscopy lends itself to the studies of selenites, selenates, tellurites and tellurates and related minerals.  The mineral schmiederite Pb2Cu2[(OH)4|SeO3|SeO4] is interesting in that both selenite and selenate anions occur in the structure.\ud
\ud
Raman bands of schmiederite at 1095 and 934 cm-1 are assigned to the symmetric and antisymmetric mode of the (SeO4)2- anions.  For selenates and selenites, the symmetric stretching mode occurs at a higher position than the antisymmetric stretching mode, as is evidenced in the Raman spectrum of schmiederite.  The band at 834 cm-1 is assigned to the symmetric (SeO3)2-  units.  The two bands at 764 and 739 cm-1 are attributed to the antisymmetric (SeO3)2-  units.  An intense sharp band at 398 cm-1 is assigned to this ν2 bending mode.\ud
The two bands at 1576 and 1604 cm-1 are assigned to the deformation modes of the OH units.  The observation of multiple OH bands supports the concept of a much distorted structure.  This is based upon the four OH units coordinating the copper in a square planar structure.  A single symmetric Raman  band is observed at 3428 cm-1 and is assigned to the symmetric stretching mode of the OH units.  The observation of multiple infrared OH stretching bands supports the concept of non-equivalent OH units in the schmiederite structure
Raman spectroscopic study of the uranyl selenite mineral marthozite Cu[(UO2)3(SeO3)2O2].8H2O

The mineral marthozite, a uranyl selenite, has been characterised by Raman spectroscopy at 298 K.  The bands at 812 and 797 cm-1 were assigned to the symmetric stretching modes of the (UO2)2+ and (SeO3)2-  units, respectively.  These values gave calculated U-O bond lengths in uranyl of 1.799 and/or 1.814 Å.  Average U-O bond length in uranyl is 1.795 Å, inferred from the X-ray single crystal structure analysis of marthozite by Cooper and Hawthorne.  The broad band at 869 cm-1 was assigned to the ν3 antisymmetric stretching mode of the (UO2)2+ (calculated U-O bond length 1.808 Å).  The band at 739 cm-1 was attributed to the ν3 antisymmetric stretching vibration of the (SeO3)2-  units.  The ν4 and the ν2 vibrational modes of the (SeO3)2-  units were observed at 424 cm-1 and 473 cm-1.  Bands observed at 257, and 199 and 139 cm-1 were assigned to OUO bending vibrations and lattice vibrations, respectively. O-H..O hydrogen bond lengths were inferred using the Libowiztky's empirical relation. The infrared spectrum of marthozite was studied for complementation
Raman spectroscopic study of the mineral guilleminite\ud
Ba(UO2)3(SeO3)2(OH)4.3H2O\ud
\ud

Raman spectrum of the mineral guilleminite Ba\[(UO2)3O2(SeO3)2](H2O)3 was studied and complemented by the infrared spectrum of this mineral. Both spectra were interpreted and compared with the spectra of marthozite, larisaite, haynesite and piretite, which all should have the same phosphuranylite anion sheet topology. The presence of symmetrically distinct water molecules and hydrogen bonds was inferred from the spectra. This is in agreement with the crystal structural analysis of guilleminite. U-O bond lengths in uranyl and O-H…O hydrogen bond lengths were calculated from the Raman and/or infrared spectra of guilleminite
Raman spectroscopic study of the selenite mineral\ud
- ahlfeldite NiSeO3.2H2O

Raman spectroscopy has been used to study the selenite mineral ahlfeldite. A comparison is made with the Raman spectra of  chalcomenite, cobaltomenite and clinochalcomenite. Selenite minerals are characterised by the position of the symmetric stretching mode which is observed at higher wavenumbers than the antisymmetric stretching mode. The selenite ion has C3v symmetry and four modes, 2A1 and 2E.  These modes are observed  at 813, 472 cm-1 (A1) and 685, 710, 727 and 367 and 396  cm-1 (E).  Bands assigned to the water stretching vibrations are observed for ahlfeldite at 3385 cm-1, for chalcomenite at 2953, 3184 and 3506 cm-1 and for clinochalcomenite at 2909, 3193 and 3507 cm-1.  A comparison of the Raman spectra of chalcomenite, clinochalcomenite and cobaltomenite is made. The position of these bands enabled hydrogen bond distances in the selenite structure to be estimated. Hydrogen bond distances for ahlfeldite, chalcomenite and clinochalcomenite were determined to be similar
Antioxidant phenolic esters with potential anticancer activity: solution equilibria studied by Raman spectroscopy

The solution Raman pattern of a series of structurally related hydroxycinnamic and hydroxybenzoicesters (caffeates and gallates) with potential antioxidant/anticancer activity was studied, for different biologically significant concentrations. The spectra were assigned with the help of theoretical calculations in the light of previously reported experimental data for these compounds in the solid state. Evidence of the formation of dimeric entities in solution, via (C)=O...H(O) and/or (C)=O...H(C) intermolecular hydrogen bonds, was obtained. The dimer-to-monomer equilibrium, which influences the antioxidant activity of this kind of systems, was monitored through Raman titration experiments. Copyright © 2008 John Wiley & Sons, Ltd.http://dx.doi.org/10.1002/jrs.208
Raman spectroscopic study of the sulphite bearing minerals scotlandite, hannebachite and orschallite : implications for the desulphation of soils

The structure of the naturally occuring sulphite bearing  minerals scotlandite, hannebachite and orschallite have been studied by Raman spectroscopy.  Raman bands are observed for scotlandite PbSO3 at 935, 880, 622 and 474 cm-1 and are assigned to the (SO3)2- ν1(A1), ν3(E), ν2(A1) and ν4(E) vibrational modes.  For hannebachite (CaSO3)2.H2O these bands are observed at 1005, 969, 655 cm-1 with multiple bands for the ν4(E) mode at 444, 492 and 520 cm-1.  The Raman spectrum of hannebachite is very different from that of the compound CaSO3.2H2O.  It is proposed, based upon Raman spectroscopy, that in the mineral hannebachite, the sulphite anion bonds to Ca through the sulphur.  The Raman spectrum of the mineral orschallite Ca3\[SO4](SO3)2.12H2O is complex resulting from the overlap of sulphate and sulphite bands.  Raman bands at 1005 cm-1 and 1096 and 1215 cm-1 are assigned to the (SO4)2- ν1 symmetric and ν3 antisymmetric stretching modes.  The two Raman bands at 971 and 984 cm-1 are attributed to the (SO3)2- ν3(E) and ν1(A1) stretching vibrations.   The formation of sulphite compounds in nature offers a potential mechanism for the removal of sulphates and sulphites from soils
Raman spectroscopic study of the tellurite minerals :  graemite CuTeO3.H2O and teineite CuTeO3.2H2O

Tellurites may be subdivided according to formula and structure.  There are five groups based upon the formulae (a) A(XO3), (b) A(XO3).xH2O, (c) A2(XO3)3.xH2O, (d) A2(X2O5) and (e) A(X3O8).  Raman spectroscopy has been used to study the tellurite minerals teineite and graemite; both contain water as an essential element of their stability.  The tellurite ion should show a maximum of six bands.  The free tellurite ion will have C3v symmetry and four modes, 2A1 and 2E.  \ud
Raman bands for teineite at 739 and 778 cm-1 and for graemite at 768 and 793 cm-1  are assigned to the ν1 (TeO3)2- symmetric stretching mode whilst  bands at 667 and 701 cm-1 for teineite and 676 and 708 cm-1 for graemite are attributed to the the ν3 (TeO3)2- antisymmetric stretching mode.  The intense Raman band at 509 cm-1 for both teineite and graemite is assigned to the water librational mode.  Raman bands for teineite at 318 and 347 cm-1 are assigned to the (TeO3)2-  ν2 (A1) bending mode and the two bands for teineite at 384 and 458 cm-1  may be assigned to the (TeO3)2-  ν4 (E) bending mode.  Prominent Raman bands, observed at 2286,  2854, 3040 and 3495 cm-1, are attributed to OH stretching vibrations. The values for these OH stretching vibrations provide hydrogen bond distances of  2.550(6) Å (2341 cm-1), 2.610(3) Å (2796 cm-1) and 2.623(2) Å (2870 cm-1) which are comparatively short for secondary minerals.\u
Raman spectroscopic study kuranakhite \ud
PbMn4+Te6+O6 –a rare tellurate mineral\ud

Tellurates are rare minerals as the tellurate anion is easily reduced to the tellurite ion.  An example of a tellurate containing mineral is kuranakhite.  Two bands at 617 and 686 cm-1 are observed and assigned to the Te6+O6 ν1 symmetric stretching mode. The observation of two bands suggests the non-equivalence of the Te6+O6 in the structure.   The broad band centred at 743 cm-1 is attributed to the Te6+O6 ν3 antisymmetric stretching mode.  Sharp intense bands at 452 and 462 cm-1 are assigned to the Te6+O6 ν4  bending mode. A comparion of the Raman spectra of kuranakhite with that of tellurate containing minerals tlapallite and xocomecatlite is made
Raman and mid-IR spectroscopic study of the magnesium carbonate minerals– brugnatellite and coalingite

Two hydrated hydroxy magnesium carbonate minerals brugnatellite and coalingite with a hydrotalcite-like structure have been studied by Raman spectroscopy.  Intense bands are observed at 1094 cm-1 for brugnatellite and at 1093 cm-1 for coalingite attributed CO32- ν1 symmetric stretching mode.  Additional low intensity bands are observed at 1064 cm-1.  The existence of two symmetric stretching modes is accounted for in terms of different anion structural arrangements.  \ud
Very low intensity bands at 1377 and 1451 cm-1 is observed for brugnatellite and the Raman spectrum of coalingite displays two bands at 1420 and 1465 cm-1 attributed to the (CO3)2- ν3 antisymmetric stretching modes.  Very low intensity bands at 792 cm-1 for brugnatellite and 797 cm-1 for coalingite are assigned to the CO32- out-of-plane bend (ν2).  \ud
X-ray diffraction studies by other researchers have shown these minerals are disordered. This is reflected in the difficulty of obtaining Raman spectra of reasonable quality and explains why the Raman spectra of these minerals have not been previously or sufficiently described.  A comparison is made with the Raman spectra of other hydrated magnesium carbonate minerals.\u
Thermo-Raman spectroscopy of selected layered double hydroxides of formula Cu6Al2(OH)16CO3 and Zn6Al2(OH)16CO3

Raman spectroscopy using a hot stage has been used to characterise layered double hydroxides (LDHs) of formula (Cu,Zn)6Al2(OH)16(CO3).4H2O.  The spectra have been used to assess the molecular assembly of the cations in the LDH structure. The sharp band at 1058 cm-1 for the Zn6Al2(OH)16(CO3).4H2O  is assigned to the ν1 CO32- symmetric stretching mode. The band shifts to higher wavenumbers and is observed at 1103 cm-1 at 600°C. It is proposed that metal carbonate species formed during the decomposition of the hydrotalcite structure is responsible for the increase in band position. The Cu-Al hydrotalcite did not show the same trend. The symmetric stretching mode of carbonate is observed at around 1110 cm-1, and at temperatures above 200 ºC a shoulder appears at around 1210 cm-1, suggested to be due to CuCO3
Raman spectroscopic study of the magnesium carbonate minerals– artinite and dypingite

Magnesium minerals are important in the understanding of the concept of geosequestration.  The two hydrated hydroxy magnesium carbonate minerals artinite and dypingite have been studied by Raman spectroscopy.  Intense bands are observed at 1092 cm-1 for artinite and at 1120 cm-1 for dypingite attributed CO32- ν1 symmetric stretching mode.  The CO32- ν3 antisymmetric stretching vibrations are extremely weak and are observed at1412 and 1465 cm-1 for artinite and at 1366, 1447 and 1524 cm-1 for dypingite.  Very weak Raman bands at 790 cm-1 for artinite and 800 cm-1 for dypingite are assigned to the CO32- ν2 out-of-plane bend.  The Raman band at 700 cm-1 of artinite and at 725 and 760 cm-1 of dypingite are ascribed to CO32-  ν2 in-plane bending mode.  The Raman spectrum of artinite in the OH stretching region is characterised by two sets of bands: (a) an intense band at 3593 cm-1 assigned to the MgOH stretching vibrations and (b) the broad profile of overlapping bands at 3030 and 3229 cm-1 attributed to water stretching vibrations.  X-ray diffraction studies show the minerals are disordered. This is reflected in the difficulty of obtaining Raman spectra of reasonable quality and explains why the Raman spectra of these minerals have not been previously or sufficiently described
Raman spectroscopic study of the metatellurate mineral :  Xocomecatlite Cu3TeO4(OH)4

The mineral xocomecatlite is a hydroxy metatellurate mineral with Te6+O4 units.  Tellurates may be subdivided according to their formula into three types of tellurate minerals: type (a) (AB)m(TeO4)pZq, type (b) (AB)m(TeO6).xH2O and (c) compound tellurates in which a second anion including the tellurite anion, is involved.  The mineral Xocomecatlite is an example of the first type.  Raman bands for xocomecatlite at 710, 763 and 796 cm-1 and 600 and 680 cm-1 are attributed to the ν1 (TeO4)2- symmetric and ν3 antisymmetric stretching mode.  Raman bands observed at 2867 and 2926 cm-1 are assigned to TeOH stretching vibrations and enable estimation of the hydrogen bond distances of 2.622 Å (2867 cm-1), 2.634 Å (2926 cm-1) involving these OH units. The hydrogen bond distances are very short implying that they are necessary for the stability of the mineral
A Raman spectroscopic study of the uranyl mineral rutherfordine – revisited

The molecular structure of the uranyl mineral rutherfordine has been investigated by the measurement of the NIR and Raman spectra and complemented with infrared spectra including their interpretation. The spectra of the rutherfordine show the presence of both water and hydroxyl units in the structure as evidenced by IR bands at 3562 and 3465 cm-1 (OH) and 3343, 3185 and 2980 cm-1 (H2O).  Raman spectra show the presence of four sharp bands at 3511, 3460, 3329 and 3151 cm-1.  Corresponding molecular water bending vibrations were only observed in both Raman and infrared spectra of one of two studied rutherfordine samples. The second rutherfordine sample studied contained only hydroxyl ions in the equatorial uranyl plane and did not contain any molecular water. The infrared spectra of the (CO3)2- units in the antisymmetric stretching region show complexity with three sets of carbonate bands observed. This combined with the observation of multiple bands in the (CO3)2- bending region in both the Raman and IR spectra suggests that both monodentate and bidentate (CO3)2- units may be present in the structure. This cannot be exactly proved and inferred from the spectra; however, it is in accordance with the X-ray crystallographic studies. Complexity is also observed in the IR spectra of (UO2)2+ antisymmetric stretching region and is attributed to non-identical UO bonds. U-O bond lengths were calculated using wavenumbers of the 3 and 1 (UO2)2+ and compared with data from X-ray single crystal structure analysis of rutherfordine. Existence of solid solution having a general formula (UO2)(CO3)1-x(OH)2x.yH2O ( x, y  0) is supported in the crystal structure of rutherfordine samples studied
Raman spectroscopic study of the mixed anion mineral \ud
Yecoraite Bi5Fe3O9(Te4+O3)(Te6+O4)2•9H2O\ud

Tellurates are rare minerals as the tellurate anion is readily reduced to the tellurite ion.  Often minerals with both tellurate and tellurite anions in the mineral are found. An example of such a mineral containing tellurate and tellurite is yecoraite.  Raman spectroscopy has been used to study this mineral, the exact structure of which is unknown. Two Raman bands at 796 and 808 cm-1 are assigned to the ν1 (TeO4)2- symmetric and ν3 (TeO3)2- antisymmetric stretching modes and Raman bands at 699 cm-1 are attributed to the the ν3 (TeO4)2- antisymmetric stretching mode and the band at 690 cm-1 to the ν1 (TeO3)2- symmetric stretching mode.  The intense band at 465 cm-1 with a shoulder at 470 cm-1 is assigned the (TeO4)2- and (TeO3)2- bending modes.  Prominent Raman bands are observed at 2878, 2936, 3180 and 3400 cm-1.    The band at 3936 cm-1 appears quite distinct and the observation of multiple bands indicates the water molecules in the yecoraite structure are not equivalent.  The values for the OH stretching vibrations listed provide hydrogen bond distances of 2.625 Å (2878 cm-1), 2.636 Å (2936 cm-1), 2.697 Å (3180 cm-1) and 2.798 Å (3400 cm-1).    This range of hydrogen bonding contributes to the stability of the mineral. A comparison of the Raman spectra of yecoraite with that of tellurate containing minerals kuranakhite, tlapallite and xocomecatlite is made
Synthesis and Raman spectroscopic study of Mg/Al,Fe hydrotalcites with variable cationic ratios

Hydrotalcites of formula Mg6 (Fe,Al)2(OH)16(CO3).4H2O formed by intercalation with the carbonate anion as a function of divalent/trivalent cationic ratio have been successfully synthesised.  The XRD patterns show variation in the d-spacing attributed to the size of the cation.   Raman and infrared bands in the OH stretching region are assigned to (a) brucite layer OH stretching vibrations (b) water stretching bands and (c) water strongly hydrogen bonded to the carbonate anion.  Multiple (CO3)2- symmetric stretching bands suggest that different types of (CO3)2- exist in the hydrotalcite interlayer.  Increasing the cation ratio (Mg/Al,Fe) resulted in an increase in the combined intensity of the 2 Raman bands at around 3600 cm-1, attributed to Mg-OH stretching modes, and a shift of the overall band profile to higher wavenumbers. These observations are believed to be a result of the increase in magnesium in the structure. Raman spectroscopy shows a reduction in the symmetry of the carbonate, leading to the conclusion that the anions are bonded to the brucite-like hydroxyl surface and to the water in the interlayer.  Water bending modes are identified in the infrared spectra at positions greater than 1630 cm-1, indicating the water is strongly hydrogen bonded to both the interlayer anions and the brucite-like surface
Raman spectroscopic study of the mixed anion sulphate-arsenate mineral parnauite Cu9[(OH)10|SO4|(AsO4)2].7H2O

The mixed anion mineral parnauite Cu9[(OH)10|SO4|(AsO4)2].7H2O\ud
has been studied by Raman spectroscopy.  Characteristic bands associated with arsenate, sulphate, hydroxyl units are identified.  Broad bands are observed and are resolved into component bands.  Two intense bands at 859 and 830 cm-1 are assigned to the 1 (AsO4)3- symmetric stretching and 3 (AsO4)3- antisymmetric stretching modes.  The comparatively sharp band at 976 cm-1 is assigned to the ν1 (SO4)2- symmetric stretching mode and a  broad spectral profile centered upon 1097 cm-1 is attributed to the  ν3 (SO4)2-  antisymmetric stretching mode.  A comparison of the Raman spectra is made with other arsenate bearing minerals such as carminite, clinotyrolite, kankite, tilasite and pharmacosiderite.  \u
Raman spectroscopic study of the uranyl mineral pseudojohannite\ud
Cu6.5[(UO2)4O4(SO4)2]2(OH)5.25H2O\ud

Raman spectra of pseudojohannite were studied and related to the structure of the mineral. Observed bands were assigned to the stretching and bending vibrations of (UO2)2+ and (SO4)2- units and of water molecules.  The published formula of pseudojohannite is Cu6.5(UO2)8\[O8](OH)5\[(SO4)4].25H2O; however Raman spectroscopy does not detect any hydroxyl units.  Raman bands at 805 and 810 cm-1 are assigned to (UO2)2+ stretching modes.  The Raman bands at 1017 and 1100 cm-1 are assigned to the (SO4)2- symmetric and antisymmetric stretching vibrations.  The three Raman bands at 423, 465 and 496 cm-1 are assigned to the (SO4)2- ν2 bending modes. The bands at 210 and 279 cm-1 are assigned to the doubly degenerate ν2 bending vibration of the (UO2)2+ units.  U-O bond lengths in uranyl and O-H…O hydrogen bond lengths were calculated from the Raman and infrared spectra
Raman spectroscopic study of the antimonate mineral brandholzite Mg[Sb(OH)12].6H2O

Raman spectra of brandholzite Mg[Sb(OH)6].6H2O were studied, complemented with infrared spectra, and related to the structure of the mineral. An intense Raman sharp band at 618 cm-1 is attributed to the SbO symmetric stretching mode.  The low intensity band at 730 cm-1 is ascribed to the SbO antisymmetric stretching vibration. Low intensity Raman bands were found at 503, 526 and 578 cm-1.  Corresponding infrared bands were observed at 527, 600, 637, 693, 741 and 788 cm-1. Four Raman bands observed at 1043, 1092, 1160 and 1189 cm-1 and eight infrared bands at 963, 1027, 1055, 1075, 1108, 1128, 1156 and 1196 cm-1 are assigned to δ SbOH deformation modes.  A complex pattern resulting from the overlapping band of the water and hydroxyl units is observed.  Raman bands are observed at 3240, 3383, 3466, 3483 and 3552 cm-1, infrared bands at 3248, 3434 and 3565 cm-1.  The first two Raman bands and the first infrared band are assigned to water stretching vibrations.  The two higher wavenumber Raman bands observed at 3466 and 3552 cm-1 and two infrared bands at 3434 and 3565 cm-1 are assigned to the stretching vibrations of the hydroxyl units. Observed Raman and infrared bands are connected with O-H…O hydrogen bonds and their lengths 2.72, 2.79, 2.86, 2.88 and 3.0 Å (Raman) and 2.73, 2.83 and 3.07 Å (infrared)
Lineshape analysis of stimulated Raman spectra of the near-nozzle region of free jet expansions

9 pages, 7 figures.-- Printed version published Sep 2009.An anomalous lineshape of stimulated Raman spectra obtained from the region very close to the nozzle of supersonic pulsed expansions of nitrogen is presented. High-resolution Raman spectra of the Q branch of the fundamental vibration mode of N2 have been recorded from two different nitrogen expansions at T0 = 295 K and P0 = 1.5-3.5 bar, the lasers crossing the jet axis in the range z/D = 0.25-1.25, where D is the effective nozzle diameter. The combination of Doppler shifts and strong gradients of density and temperature in the near-nozzle region yield an inhomogeneous broadening and a double peak structure of the recorded Raman line profiles. The comparison of the experimental results with the simulation of the Raman spectrum from this region provides valuable information about the near-nozzle flow field. The lineshape described here is different from another reported previously in the literature, which is based on a depletion of the density of free molecules on the axis due to condensation.A. Ramos acknowledges CSIC for an I3P grant. This work has been funded by the DGI (MEC) of Spain under grants ENE 2006-14577-C04-03/FTN, FIS 2004-02558, FIS 2005-02029, and FIS \ud
2007-61686.Peer reviewe