far-IR Spectra Research Articles

Magnetism, IR and Raman spectra of a tetracoordinate and hexacoordinate Co(II) complexes derived from aminopyrimidine

Two mononuclear Co(II) complexes of the [CoCl2L2] and [CoCl2L4] family, with L being a heterocyclic N-donor ligand – 2-aminopyrimidine were prepared and subjected to magnetochemical investigation. Temperature dependence of the magnetic susceptibility and the field dependence of magnetization have been analyzed simultaneously in terms of the spin Hamiltonian formalism. The magnetic parameters obtained by a fitting procedure show a considerable magnetic anisotropy measured by the g-factor difference and the zero-field splitting parameter 2D, which splits the ground 4B1(D2d) term and/or 4A1g(D4h) term. The temperature dependence of the Far-IR spectra for the centrosymmetric hexacoordinate complex shows variable-temperature absorption peaks which yield the value of the zero-field energy gap ΔIR=455cm−1. Raman spectra, ab initio and DFT calculations assist in an accurate assignment of the absorption peaks.

On the carbonaceous carriers of infrared plateau and continuum emission

This study explores the molecular origins of plateaus and continua underlying the infrared and far-infrared (far-IR) bands emitted by compact nebulae, especially protoplanetary nebulae. Computational organic chemistry codes are used to deliver the vibrational integrated band intensities of various large, typical carbonaceous structures. These spectra are composed of a rather continuous distribution of weak modes from which emerge the fingerprints. The 6–18 μm region is interspersed with a great many weak lines, to which the plateaus are assigned. Similarly, the far-IR spectrum is ascribed to the phonon (skeletal) spectrum which is readily identified beyond 18 μm. The absorptivities and absorption cross-sections per interstellar H atom deduced from these spectra are comparable with those of laboratory dust analogues and astronomical measurements, respectively. Moreover, the 5–35 μm spectra of two typical protoplanetary nebulae were reasonably well simulated with combinations of molecules containing functional groups which carry the 21- and 30-μm bands, and molecules devoid of these but carrying strong phonon spectra. These results may help understand the emergence of plateaus, the origin of continua underlying far-IR bands, as well as the composition of circumstellar dust.

L-Serine in aqueous solutions at different pH: Conformational preferences and vibrational spectra of cationic, anionic and zwitterionic species

The aim of this study is to understand the conformational preferences of l-Serine (C3H7NO3, 2-amino-3-hydroxypropanoic acid) at different pH conditions. A conformational study in aqueous solution of the dissociation equilibrium of the polar amino acid l-Serine, was carried out for this purpose. We recorded, at room temperature, the Mid-IR, FarIR and Raman spectra of l-Serine from the aqueous solutions at pH values 5.82 (zwitterionic species), 1.00 (protonated species) and 13.00 (deprotonated species). Both the study of the conformational landscape and the theoretical analysis of the vibrational features were done using DFT and ab initio calculations, i.e. B3LYP/6-31+G(d,p), M062X/6-31+G(d,p) and MP2/6-31+G(d,p) levels of theory. The presence of water was included with the IEF-PCM implicit hydration model. Concerning the zwitterion, analysis of the low frequency region (700–50cm−1) in the FT-Raman and FarIR spectra reveals important information for assignment of the most stable structures.

Influence of Intense THz Radiation on Spin State of Photoswitchable Compound Cu(hfac)2LPr

The family of magnetoactive compounds Cu(hfac)(2)L(R) exhibits thermo- and photoswitching phenomena promising for various applications. Photoswitching of the Cu(hfac)(2)L(Pr) compound can be observed at temperatures below 20 K and is accompanied by transition to metastable structural state. Reverse conversion to stable structure could not be induced by light of near-IR-vis-UV regions up to date. The far-IR spectra of metastable and stable structural states are different and show characteristic absorption lines in the range of 170-240 cm(-1). These frequencies are accessible by NovoFEL - high-power THz free-electron laser user facility in Novosibirsk. We investigate selective influence of THz radiation on relaxation processes from metastable to stable structural state, which can be monitored by electron paramagnetic resonance (EPR). For this purpose, the experimental station based on X-band EPR spectrometer has been constructed by the THz beamline of NovoFEL and equipped with multimodal THz waveguide allowing to fed radiation directly into the EPR resonator. It has been found that irradiation of studied compound with high-power THz light causes significant but nondestructive increase of its temperature. Apart from this effect, no resonant influence of THz irradiation on relaxation processes has been observed. The experimental results have been rationalized taking into account vibrational relaxation times of the studied compound. Further experiments based on pulse heating by THz radiation have been proposed.

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

ABSTRACT New Hofmann–Td-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–Td-type clathrates.

Dissecting Anion–Cation Interaction Energies in Protic Ionic Liquids

The strength of the interaction between anions and cations in protic ionic liquids (PILs) can be extracted from far-IR spectra. A suitable set of specially synthesized PILs was used to correct the frequency shifts of these low vibrational modes for contributions resulting from changing reduced masses only. The experimental results were confirmed by DFT calculations. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Comparisons of Clear-Sky Outgoing Far-IR Flux Inferred from Satellite Observations and Computed from the Three Most Recent Reanalysis Products

Abstract The far-IR spectrum plays an important role in the earth’s radiation budget and remote sensing. The authors compare the near-global (80°S–80°N) outgoing clear-sky far-IR flux inferred from the collocated Atmospheric Infrared Sounder (AIRS) and Clouds and the Earth’s Radiant Energy System (CERES) observations in 2004 with the counterparts computed from reanalysis datasets subsampled along the same satellite trajectories. The three most recent reanalyses are examined: the ECMWF Interim Re-Analysis (ERA-Interim), NASA Modern-Era Retrospective Analysis for Research and Application (MERRA), and NOAA/NCEP Climate Forecast System Reanalysis (CFSR). Following a previous study by X. Huang et al., clear-sky spectral angular distribution models (ADMs) are developed for five of the CERES land surface scene types as well as for the extratropical oceans. The outgoing longwave radiation (OLR) directly estimated from the AIRS radiances using the authors’ algorithm agrees well with the OLR in the collocated CERES Single Satellite Footprint (SSF) dataset. The daytime difference is 0.96 ±2.02 W m−2, and the nighttime difference is 0.86 ±1.61 W m−2. To a large extent, the far-IR flux derived in this way agrees with those directly computed from three reanalyses. The near-global averaged differences between reanalyses and observations tend to be slightly positive (0.66%–1.15%) over 0–400 cm−1 and slightly negative (−0.89% to −0.44%) over 400–600 cm−1. For all three reanalyses, the spatial distributions of such differences show the largest discrepancies over the high-elevation areas during the daytime but not during the nighttime, suggesting discrepancies in the diurnal variation of such areas among different datasets. The composite differences with respect to temperature or precipitable water suggest large discrepancies for cold and humid scenes.

Communication: Structure of magnetic lanthanide clusters from far-IR spectroscopy: ${\rm Tb}_n^+$ Tb n+ (n = 5−9)

Small lanthanide clusters have interesting magnetic properties, but their structures are unknown. We have identified the structures of small terbium cluster cations Tb(n)(+) (n = 5-9) in the gas phase by analysis of their vibrational spectra. The spectra have been measured via IR multiple photon dissociation of their complexes with Ar atoms in the 50-250 cm(-1) range with an infrared free electron laser. Density functional theory calculations using a 4f-in-core effective core potential (ECP) accurately reproduce the experimental far-IR spectra. The ECP corresponds to a 4f(8)5d(1)6s(2) trivalent configuration of terbium. The assigned structures are similar to those observed in several other transition metal systems. From this, we conclude that the bonding in Tb clusters is through the interactions between the 5d and 6s electrons, and that the 4f electrons have only an indirect effect on the cluster structures.

HERSCHEL/PACS SPECTROSCOPIC SURVEY OF PROTOSTARS IN ORION: THE ORIGIN OF FAR-INFRARED CO EMISSION

We present far-IR (57-196 mu) spectra of 21 protostars in the Orion molecular clouds, obtained with the Photodetector Array Camera and Spectrometer (PACS) onboard the Herschel Space observatory, as part of the Herschel Orion Protostar Survey (HOPS) program. We analyzed the CO emission lines (J_up = 14-46) in the PACS spectra, extracted within a projected distance of <= 2000 AU centered on the protostar. The total luminosity of the CO lines observed with PACS (L(CO)) is found to increase with increasing L_bol. The CO rotational temperature implied by the line ratios increases with J, and at least 3-4 rotational temperature components are required to fit the observed rotational diagram. The rotational temperature components are remarkably invariant between protostars and show no dependence on L_bol, T_bol or envelope density, implying that if the emitting gas is in LTE, the CO emission must arise in multiple temperature components that remain independent of L_bol over two orders of magnitudes. The observed CO emission can also be modeled as arising from a single temperature gas component or from a medium with a power-law temperature distribution; both of these require sub-thermally excited molecular gas at low densities (n(H_2) <= 10^6 cm^-3) and high temperatures (T >= 2000 K). Our results suggest that the contribution from PDRs along the envelope cavity walls is unlikely to be the dominant component of the CO emission observed with PACS. Instead, the "universality" of the rotational temperatures and the observed correlation between L(CO) and L_bol can most easily be explained if the observed CO emission originates in shock-heated, hot (T >= 2000 K), sub-thermally excited (n(H_2) <= 10^6 cm^-3) molecular gas. Post-shock gas at these densities is more likely to be found within the outflow cavities along the molecular outflow or along the cavity walls at radii >= several 100-1000 AU.

Far-infrared spectroscopy of the troposphere: instrument description and calibration performance

The far-infrared spectroscopy of the troposphere (FIRST) instrument is a Fourier transform spectrometer developed to measure the Earth's thermal emission spectrum with a particular emphasis on far-infrared (far-IR) wavelengths greater than 15 μm. FIRST was developed under NASA's Instrument Incubator Program to demonstrate technology for providing measurements from 10 to 100 μm (1000 to 100 cm(-1)) on a single focal plane with a spectral resolution finer than 1 cm(-1). Presently no spectrometers in orbit are capable of directly observing the Earth's far-IR spectrum. This fact, coupled with the fundamental importance of the far-IR to Earth's climate system, provided the impetus for the development of FIRST. In this paper the FIRST instrument is described and results of a detailed absolute laboratory calibration are presented. Specific channels in FIRST are shown to be accurate in the far-IR to better than 0.3 K at 270 K scene temperature, 0.5 K at 247 K, and 1 K at 225 K.

Far-infrared absorption spectra of synthetically-prepared, ligated metal clusters with Au6, Au8, Au9 and Au6Pd metal cores

The far infra-red absorption spectra of a series of chemically synthesised, atomically precise phosphine-stabilised gold cluster compounds have been recorded using synchrotron light for the first time. Far-IR spectra of the Au6(Ph2P(CH2)3PPh2)4(NO3)2, Au8(PPh3)8(NO3)2, Au9(PPh3)8(NO3)3, and Pd(PPh3)Au6(PPh3)6(NO3)2 clusters reveal a complex series of peaks between 80 and 475 cm−1, for which all significant peaks can be unambiguously assigned by comparison with Density Functional Theory (DFT) geometry optimisations and frequency calculation. Strong absorptions in all spectra near 420 cm−1 are assigned to the P–Ph3 stretching vibrations. Distinct peaks within the spectrum of each specific cluster are assigned to the cluster core vibrations: 80.4 and 84.1 cm−1 (Au6) 165.1 and 166.4 cm−1 (Au8), 170.1 and 185.2 cm−1 (Au9), and 158.9, 195.2, and 206.7 cm−1 (Au6Pd). The positions of these peaks are similar to those observed to occur for the neutral Au7 cluster in the gas phase (Science, 2008, 321, 674–676). Au–P stretching vibrations only occur for Au6 near 420 cm−1, although they appear near 180 cm−1 for Au6Pd and involve gold core vibrations.

Spectroscopic Studies of the Complexation of Iodine with Antihistamine Drugs in Solvents of Varying Relative Permittivity

The interaction of oxatomide (OXA), azacyclonol (AZA) and chloropheniramine (ClPA) antihistamine drugs with iodine was studied spectrophotometrically in different solvents and at three different temperatures. The electronic, FT-IR, far-IR, and mass spectra of the resulting charge-transfer (CT) complexes were recorded, in addition to thermal analysis. The results obtained show that the stoichiometries of the reactions are all 1:1. The observed time dependence of the CT band and subsequent formation of \( {\text{I}}_{3}^{ - } \) in solution were related to the slow transformation of the initially formed 1:1 (donor: I2) outer complex to an inner complex (electron donor–acceptor), followed by a fast reaction of the inner complex with iodine to form a triiodide ion. The characteristic strong absorptions of \( {\text{I}}_{3}^{ - } \) are observed around 360 nm. The CT-complexes have the formulae [(OXA)I]+\( {\text{I}}_{3}^{ - } \), [(AZA)I]+\( {\text{I}}_{3}^{ - } \) and [(ClPA)I]+\( {\text{I}}_{3}^{ - } \). The formation constants (K), molar absorption coefficients (eCT), and thermodynamic parameters ΔH#, ΔS# and ΔG# of these interaction have been determined and discussed.

Pressure-induced phase transitions in ilvaite studied by in situ micro-FTIR spectroscopy

Mid- and Far-infrared spectra of a natural ilvaite sample were collected in situ in a diamond-anvil cell (DAC) as a function of pressure. The composition of the natural material is Ca 2+ 0.94 (Fe 2+ 0.61 Mn 2+ 0.40 )(Fe 3+ 1.01 Fe 2+ 0.96 Al 3+ 0.02 Mg 2+ 0.01 )[Si 2.03 O 7 /O/ (OH)] as determined by electron microprobe. One series of DAC experiments was performed at GFZ in the Mid-IR using argon as pressure medium and a Globar as light source. Four pressure series were performed at Bessy II in the Far-IR region using petroleum jelly as pressure medium and synchrotron light. For the Far-IR region we used a custom-made vacuum microscope adapted to an FTIR spectrometer. Pressure-induced changes in the Mid- and Far-IR spectra were analysed via the autocorrelation method for all five pressure series. All five series confirm the monoclinic to orthorhombic phase transition at about 2.3 GPa already known from X-ray diffraction studies. Our results show that incorporation of Mn 2+ does not lower the transition pressure as reported previously. However, the magnitude of the initial monoclinic β angle and the concentration of impurities seem to control the transition pressure. The first evidence of a second pressure-induced phase transition at much higher pressure (between 10 and 11 GPa) is reported here. Both transitions are clearly visible throughout the whole spectral ranges: in the OH-stretching region, the Mid-IR region from 1400 to 400 cm −1 and in the Far-IR region down to 50 cm −1 . The structural change at 10.5 GPa observed via infrared spectroscopy may reflect a pressure-induced suppression of the Jahn–Teller effect of the strongly distorted M2 octahedron. Above 11 GPa and up to 20 GPa no further discontinuities could be detected. One series going in pressure up to 31 GPa may indicate an additional structural change above 20 GPa.

THz Observations of the Cool Neutral Medium

AbstractThe astrophysical drivers for far-infrared spectroscopy of the Galactic interstellar medium using a 15m class telescope on Dome A are compelling. For the diffuse, atomic phase, the most important lines in the far-IR spectrum are OIat 63μm and CIIat 158μm. These are the dominant cooling lines of the cool, neutral medium, and they show rich spectral structure in Herschel observations at low latitudes. But theory predicts that they should both be highly sub-thermal in excitation, so that the level populations are not in equilibrium with the kinetic temperature of the gas. A large single dish telescope or an interferometer may be able to study the absorption and emission to determine the optical depth and column density of atoms and the physical conditions in the emission regions. Comparison of Herschel CIIspectra with 21-cm absorption spectra indicates that a significant fraction of the 158μm flux may be coming from the atomic rather than the molecular phase.

Conformational preference of short aromatic amino acids from the FT-IR, FT-Raman and Far-IR spectroscopies, and quantum chemical calculations: l-phenylalanine and l-tyrosine

From the analysis of the vibrational Mid-IR, Raman and Far-IR spectra of the α-amino acids l-phenylalanine and l-tyrosine, we are able to explain the conformational preference of their zwitterionic forms, which are of biological interest. The recorded spectra of l-Phe and l-Tyr in the solid state have been analyzed and compared with a large set of quantum chemical calculations in order to better understand the zwitterionic structures experimentally detected. In this way, analysis of the low frequency region between 500 and 30cm−1 reveals much information in order to assign the most stable structures. The present work reveals that IR, Raman, and Far-IR, combined with quantum chemical calculations, are helpful and complementary techniques to characterize biological systems, such as amino acids.

X-ray structure analysis and vibrational spectra of Furosemide

In this study, FT-IR, FAR-IR, and FT-Raman spectra of Furosemide were recorded between 4000 and 650cm−1, 700 and 150cm−1 and 4000 and 150cm−1 regions, respectively. In addition, the single crystal, X-ray structure is determined for this molecule. The X-ray analysis showed two alternative orientations; E and Z-form which formed dimer structure by OH…O hydrogen bonds. The theoretical analysis of probable stable conformers of Furosemide was carried out by using DFT method with 6-31G(d,p) basis set while density functional theory (DFT/B3LYP) method with 6-31G(d,p), 6-31G(d) and Sadlej PVTZ as basis sets was used for quantum chemical calculations of geometrical structure and vibrational wavenumbers. Additionally, the anharmonic wavenumbers were calculated by using the same theory with 6-31G(d,p) basis set. A detailed interpretation of the infrared and Raman spectra of Furosemide was made based on total energy distribution (TED). Finally, probable donor–acceptor interactions of E and Z form of the molecule were examined by using NBO analysis.

Water in star-forming regions withHerschel: highly excited molecular emission from the NGC 1333 IRAS 4B outflow

During the embedded phase of pre-main sequence stellar evolution, a disk forms from the dense envelope while an accretion-driven outflow carves out a cavity within the envelope. Highly excited H2O emission in spatially unresolved Spitzer/IRS spectra of a low-mass Class 0 object, NGC 1333 IRAS 4B, has previously been attributed to the envelope-disk accretion shock but could instead be produced in an outflow. As part of the survey of low-mass sources in the Water in Star Forming Regions with Herschel (WISH-LM) program, we used Herschel/PACS to obtain a far-IR spectrum and several Nyquist-sampled spectral images with to determine the origin of excited H2O emission from NGC 1333 IRAS 4B. The spectrum has high signal-to-noise in a rich forest of H2O, CO, and OH lines, providing a near-complete census of far-IR molecular emission from a Class 0 protostar. The excitation diagrams for the three molecules all require fits with two excitation temperatures, indicating the presence of two physical components. The highly excited component of H2O emission is characterized by subthermal excitation of 1500 K gas with a density of 10^5 - 10^7 cm-3, conditions that also reproduce the mid-IR H2O emission detected by Spitzer. On the other hand, a high density, low temperature gas can reproduce the H2O spectrum observed by Spitzer but underpredicts the H2O lines seen by Herschel. Nyquist-sampled spectral maps of several lines show two spatial components of H2O emission, one centered at 1200 AU south of the central source at the position of the blueshifted outflow lobe and a second centered on-source. Both spatial components of the far-IR H2O emission are consistent with emission from the outflow. The gas cooling from the IRAS 4B envelope cavity walls is dominated by far-IR H2O emission, in contrast to stronger [O I] and CO cooling from more evolved protostars. [one sentence truncated]

Laboratory far-infrared spectroscopy of terrestrial sulphides to support analysis of cosmic dust spectra

As an aid in interpreting data from space far-infrared (far-IR) missions, such as the Herschel Space Observatory with its Photodetector Array Camera and Spectrometer, this paper presents spectroscopic studies of selected naturally occurring terrestrial sulphide minerals in the wavelength range 15–250 μm. The data can also be used to support the return from other, both past and planned, IR space missions, such as the Infrared Space Observatory, Spitzer, SOFIA, SPiCA and Millimetron. In this study, we present far-IR spectra for 11 natural sulphide minerals in the form of dispersed powders of micron particle dimensions. Samples of various sulphides from the American Museum of Natural History mineral collection were selected based on criteria of diversity and potential astrophysical relevancy, based on their identification in Stardust, in stratospheric interplanetary dust particle samples, or in meteorites. Mineral species include digenite, galena, alabandite, sphalerite, wurtzite, covellite, pyrrhotite, pyrite, marcasite, chalcopyrite and stibnite. Most of the sulphides examined possess prominent and characteristic features in the far-IR range. Spectra obtained are compared to those available from previous studies. Far-IR peak frequencies and mass absorption coefficient values are tabulated. Effects of particle size distribution, low temperature, and provenance on IR spectra are demonstrated for selected samples.

Mechanochemical and solution synthesis, X-ray structure and IR and 31P solid state NMR spectroscopic studies of copper(i) thiocyanate adducts with bulky monodentate tertiary phosphine ligands

A number of adducts of copper(I) thiocyanate with bulky tertiary phosphine ligands, and some nitrogen-base solvates, were synthesized and structurally and spectroscopically characterised. CuSCN:PCy3 (1:2), as crystallized from pyridine, is shown by a single crystal X-ray study to be a one-dimensional polymer ...(Cy3P)2CuSCN(Cy3P)2CuSCN... (1) with the four-coordinate copper atoms linked end-on by S-SCN-N bridging thiocyanate groups. A second form (2), obtained from acetonitrile, was also identified and shown by IR and 31P CPMAS NMR spectroscopy to be mononuclear, with the magnitude of the dν(Cu) parameter measured from the 31P CPMAS and the ν(CN) value from the IR clearly establishing this compound as three-coordinate [(Cy3P)2CuNCS]. Two further CuSCN/PCy3 compounds CuSCN:PCy3 (1:1) (3), and CuSCN:PCy3:py (1:1:1) (4) were also characterized spectroscopically, with the dν(Cu) parameters indicating three- and four-coordinate copper sites, respectively. Attempts to obtain a 1:2 adduct with tri-t-butylphosphine have yielded, from pyridine, the 1:1 adduct as a dimer [(Bu(t)3P)((SCN)(NCS))Cu(PBu(t)3)] (5), while similar attempts with tri-o-tolylphosphine (from acetonitrile and pyridine (= L)) resulted in solvated 1:1:1 CuSCN:P(o-tol)3:L forms as dimeric [{(o-tol)3P}LCu((SCN)(NCS))CuL{P(o-tol)3}] (6 and 8). The solvent-free 1:1 CuSCN:P(o-tol)3 adduct (7), obtained by desolvation of 6, was characterized spectroscopically and dν(Cu) measurements from the 31P CPMAS NMR data are consistent with the decrease in coordination number of the copper atom from four (for 6) (P,N(MeCN)Cu,S,N) to three (for 7) (PCuS,N) upon loss of the acetonitrile of solvation. These results are compared with those previously reported for mononuclear and binuclear PPh3 adducts which demonstrate a clear tendency for the copper centre to remain four-coordinate. The IR spectroscopic measurements on these compounds show that bands in the far-IR spectra provide a much more definitive criterion for distinguishing between bridging and terminal bonding than does an often-used empirical rule based on ν(CN) in the mid-IR, which leads to the wrong conclusion in some cases.

FTIR and DSC Study of Se&lt;sub&gt;92&lt;/sub&gt;Te&lt;sub&gt;8-x&lt;/sub&gt;Sn&lt;sub&gt;x &lt;/sub&gt;(x=0, 3 and 5) Chalcogenide Glasses

In the present work, DSC and FTIR study of the of Se92Te8-xSnx ( x=0, 2 and 4) glassy samples has been studied. FTIR spectra was taken in wavelength region 50-600 cm-1. The parameters like theoretical wave number and activation energy of glass transition and crystallization has been calculated by Kissinger’method and Augis and Bennett’approximation. With the addition of Sn, Far-IR spectra shift toward high frequency side and new bands starts appearing in the spectra. The Sn atom appear to substitute for the selenium atoms in the outrigger sites due to large bond formation probability. Activation energy of glass transition increases with Sn addition while for crystallization, it also increases except at x=1.