Thermo‐Raman spectroscopy of synthetic nesquehonite — implication for the geosequestration of greenhouse gases

Pure nesquehonite (MgCO₃·3H₂O)/Mg(HCO₃)(OH)·2H₂O was synthesised and characterised by a combination of thermo‐Raman spectroscopy and thermogravimetry with evolved gas analysis. Thermo‐Raman spectroscopy shows an intense band at 1098 cm⁻¹, which shifts to 1105 cm⁻¹ at 450 °C, assigned to the ν₁CO₃²⁻ symmetric stretching mode. Two bands at 1419 and 1509 cm⁻¹ assigned to the ν₃ antisymmetric stretching mode shift to 1434 and 1504 cm⁻¹ at 175 °C. Two new peaks at 1385 and 1405 cm⁻¹ observed at temperatures higher than 175 °C are assigned to the antisymmetric stretching modes of the (HCO₃)⁻ units. Throughout all the thermo‐Raman spectra, a band at 3550 cm⁻¹ is attributed to the stretching vibration of OH units. Raman bands at 3124, 3295 and 3423 cm⁻¹ are assigned to water stretching vibrations. The intensity of these bands is lost by 175 °C. The Raman spectra were in harmony with the thermal analysis data. This research has defined the thermal stability of one of the hydrous carbonates, namely nesquehonite. Thermo‐Raman spectroscopy enables the thermal stability of the mineral nesquehonite to be defined, and, further, the changes in the formula of nesquehonite with temperature change can be defined. Indeed, Raman spectroscopy enables the formula of nesquehonite to be better defined as Mg(OH)(HCO₃)·2H₂O. Copyright © 2008 John Wiley & Sons, Ltd.     

The structure and vibrational features of proton disolvates in water–ethanol solutions of HCl: the combined spectroscopic and theoretical study

The infrared (IR) spectra of water–ethanol (EtOH) solutions of HCl are measured over a wide range of acid concentration at fixed H₂O―EtOH ratios (1 : 1, 1 : 2, and 1 : 40). In these systems, different proton disolvates with (quasi)symmetrical H‐bonds are formed. Their structure and vibrational features are revealed by the density functional theory method coupled with the polarizable continuum model of solvation. In dilute acidic solutions, the Zundel‐type H₅O₂⁺ ion is mainly formed. In concentrated HCl solutions, the ions (H₂O···H···O(H)Et)⁺ and (Et(H)O···H···O(H)Et)⁺ with the quasi‐symmetrical O···H⁺···O unit having O···O separation <2.45 Å appear. The first ion characterized by the IR‐intensive band around 1800 cm^?1 is mainly formed in the 1 : 1 water–ethanol systems. The second ion exists in the 1 : 2 and 1 : 40 water–ethanol systems. Its spectroscopic signatures are the groups of the IR‐intensive bands around 800 and 1050 cm^?1. In highly concentrated HCl solutions with the 1 : 40 water–ethanol ratio, a neutral Et(H)O···H⁺···Cl^? complex exists. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermal Dehydration and Vibrational Studies of ZnK4(P3O9)2 · 6H2O

The thermal dehydration of ZnK₄(P₃O₉)₂ · 6H₂O was studied in the range 25–500°C by thermogravimetric analysis (TGA and DSC) and X‐ray diffraction. We found, based on the TGA and DSC scans, the dehydration of this salt takes place in three stages with a loss of the six water molecules. The infrared and Raman spectra of ZnK₄(P₃O₉)₂ · 6H₂O have been recorded and interpreted using a factor group analysis. The internal modes are assigned in terms of POP and PO₂ structural units using experimental and theoretical IR and Raman frequencies.     

Raman spectroscopy of gallium‐ and zinc‐based hydrotalcites

Insight into the unique structure of hydrotalcites (HTs) has been obtained using Raman spectroscopy. Gallium‐containing HTs of formula Zn₄ Ga₂(CO₃)(OH)₁₂ · xH₂O (2:1 ZnGa‐HT), Zn₆ Ga₂(CO₃)(OH)₁₆ · xH₂O (3:1 ZnGa‐HT) and Zn₈ Ga₂(CO₃)(OH)₁₈ · xH₂O (4:1 ZnGa‐HT) have been successfully synthesised and characterised by X‐ray diffraction (XRD) and Raman spectroscopy. The d(003) spacing varies from 7.62 Å for the 2:1 ZnGa‐HT to 7.64 Å for the 3:1 ZnGa‐HT. The 4:1 ZnGa‐HT showed a decrease in the d(003) spacing, compared to the 2:1 and 3:1 compounds. Raman spectroscopy complemented with selected infrared data has been used to characterise the synthesised gallium‐containing HTs. Raman bands observed at around 1050, 1060 and 1067 cm⁻¹ are attributed to the symmetric stretching modes of the (CO₃²⁻) units. Multiple ν₃ (CO₃²⁻) antisymmetric stretching modes are found between 1350 and 1520 cm⁻¹, confirming multiple carbonate species in the HT structure. The splitting of this mode indicates that the carbonate anion is in a perturbed state. Raman bands observed at 710 and 717 cm⁻¹ and assigned to the ν₄ (CO₃²⁻) modes support the concept of multiple carbonate species in the interlayer. Copyright © 2010 John Wiley & Sons, Ltd.     

Structure of ZnZrF<Subscript>6</Subscript> · <Emphasis Type="Italic">n</Emphasis>H<Subscript>2</Subscript>O (<Emphasis Type="Italic">n</Emphasis> = 6–2) and ZnZrF<Subscript>6</Subscript> crystallohydrates according to vibrational spectroscopy data

Fluoridezirconate crystallohydrates ZnZrF₆ · nH₂O (n = 6–2) and anhydrous ZnZrF₆ are investigated by vibrational spectroscopy and thermography. The influence of the hydrate number on the structure of the cationic and anionic sublattices of the crystallohydrates is studied. The changes in the strength of HOH···F and HOH···O hydrogen bonds of coordinated and outer-sphere water molecules occurring with variations in the hydrate number are determined by changes in the IR spectra. The IR spectra of ZnZrF₆ · nH₂O (n =6, 4) compounds, which have isolated complex anions [ZrF₆]^2– in their structure, revealed a band with two peaks in the range of 3470–3430 cm^–1, which corresponds to stretching vibrations of coordinated water molecules. The spectra of ZnZrF₆ · nH₂O (n = 5, 3, 2, 1) crystallohydrates with a polymeric structure show a high-frequency shift of this band, which corresponds to weakening of hydrogen bonds. The vibrations of crystallization water molecules involved in the network of strong O–H···F and O–H···O hydrogen bonds manifest themselves in the spectra of ZnZrF₆ · nH₂O (n =5, 3) crystallohydrates by broad structureless bands in the region of stretching, bending, and libration vibrations.     

Structural studies of some new lamellar magnesium,manganese and calcium phosphonates

Layered phosphonate salts of divalent metal ions (Mg, Ca and Mn) are prepared by combining solutions of soluble metal salts and alkyl- or arylphosphonic acids. In this way the compounds Mg(O₃PC_{nH2n+1)·H2O (n=1−12), Mg(O3PC6H5)·H2O, Mg(HO3PCH(C6H5)2)2·8 H2O, Mn(O3PCH3)·H2O, Mn(O3PC6H5)·H2O, Ca(O3PCnH2n+1)·H2O (n⩽5), Ca(HO3PC6H5)2 and Ca(HO3PCnH2n+1)2 (n⩾6) were prepared. The M(O3PC6H5)·H2O compounds show good thermal stability, losing lattice water at 250–300°C without further decomposition below 550°C. Compounds derived from alkylphosphonic acids decompose at lower temperatures. The Mg(O3PCnH2n+1)·H2O series, Mg(O3PC6H5)·H2O, and Mn(O3PC6H5)·H2O group Pmn21; for the latter compound unit cell dimensions (Å) are a=5.733, b=14.298, c=4.931. The structure consists of roughly coplanar layers of metal atoms coordinated by phenylphosphonate groups above and below. Each metal atom is coordinated by five phosphonate oxygens and one lattice water molecule. Mg(O3PCnH2n+1}·H₂O adopts a similar structure; infrared spectra indicate all-trans alkyl chains. In Mg(HO₃PCH(C₆H₅)₂)₂·8 H₂O, Mg(H₂O)²⁺₆ ions and lattice water lie in hydrogen-bonded sheets; the benzhydryl groups lie above and below and make van-der-Waals contacts between layers.     

Raman spectroscopic study of the hydrogen and arsenate bonding environment in isostructural synthetic arsenates of the variscite group—M3+ AsO4·2H2O (M3+ = Fe,Al, In and Ga): implications for arsenic release in water

The Raman spectra of synthetic compounds equivalent to the variscite group: FeAsO₄·2H₂O AlAsO₄·2H₂O, GaAsO₄·2H₂O, and InAsO₄·2H₂O are reported. In particular, upon comparison of FeAsO₄·2H₂O to AlAsO₄·2H₂O, it is observed that the Type II (weak) H‐bond lengths in the latter are slightly longer, which is postulated to affect the stability (As release) in water at pH 5 and 7. Arsenate stretching and bending vibrations were found to be distinct in terms of spectral structure and therefore well suited for fingerprinting. The calculated As O bond strengths from existing crystallographic data showed no significant variations. The strongest ν₁ (AsO₄³⁻) stretch was used to monitor the As O bonding interactions in the four As O M units, where a shift of 114 cm⁻¹ was observed in the order FeAsO₄·2H₂O (lowest) < InAsO₄·2H₂O < GaAsO₄·2H₂O < AlAsO₄·2H₂O (highest); this order also followed exactly the measured arsenic release of these phases. This shift in ν₁ (AsO₄³⁻) position was rationalized to stem from the differences in the electronegativities of the M³⁺ cations. The trends mentioned above were verified and found to also hold for the isostructural phosphate analogues strengite (FePO₄·2H₂O) and variscite (AlPO₄·2H₂O) using published data. Therefore, it is postulated that, as observed with the stability of solution complexes, there may be a correlation between the electronegativity of the M³⁺ cation in these isostructural phases and their stability (As or P release) in water. Copyright © 2010 John Wiley & Sons, Ltd.     

Raman spectroscopic study of the uranyl carbonate mineral zellerite

Raman and infrared spectra of the uranyl mineral zellerite, Ca[(UO₂)(CO₃)₂(H₂O)₂]·3H₂O, were measured and tentatively interpreted. U O bond in uranyl and O H···O hydrogen bonds were calculated from the vibrational spectra. The presence of structurally nonequivalent water molecules in the crystal structure of zellerite was inferred. A proposed chemical formula of zellerite is supported. Raman bands at 3514, 3375 and 2945 cm⁻¹and broad infrared bands at 3513, 3396 and 3326 cm⁻¹ are related to the ν OH stretching vibrations of hydrogen‐bonded water molecules. Observed wavenumbers of these vibrations prove that in fact hydrogen bonds participate in the crystal structure of zellerite. The presence of two bands at 1618 and 1681 cm⁻¹ proves structurally distinct and nonequivalent water molecules in the crystal structure of zellerite. Copyright © 2008 John Wiley & Sons, Ltd.     

Gadolinium orthophosphate weinschenkite type and phase change in rare earth orthophosphates

Some properties of rare earth orthophosphates have been determined by means of synthesis, X-ray diffraction, infrared absorption spectra, and Raman spectra measurements. The results are: (1) a synthesis of new compounds GdPO₄.2H₂O weinschenkite type, (2) the salt readily lost its water and changed from the weinschenkite to the xenotime form at about 300°C in air, (3) the change phase in rare earth orthophosphates showed that the weinschenkite phase can give rise to rhabdophane or xenotime phases, and (4) the orthorhombic form DyPO₄·1.5H₂O is explainable in terms of a mixture of rhabdophane and xenotime-structured material.     

Computational study on structures,thermochemical properties,and bond energies of disulfide oxygen (S–S–O)‐bridged CH3SSOH and CH3SS(=O)H and radicals

Cleavage of disulfide bonds is a common method used in linking peptides to proteins in biochemical reactions. The structures, internal rotor potentials, bond energies, and thermochemical properties (Δ_fH°, S°, and Cp(T)) of the S–S bridge molecules CH₃SSOH and CH₃SS(=O)H and the radicals CH₃SS?=O and C?H₂SSOH that correspond to H‐atom loss are determined by computational chemistry. Structure and thermochemical parameters (S° and Cp(T)) are determined using density functional Becke, three‐parameter, Lee–Yang–Parr (B3LYP)/6‐31++G (d, p), B3LYP/6‐311++G (3df, 2p). The enthalpies of formation for stable species are calculated using the total energies at B3LYP/6‐31++G (d, p), B3LYP/6‐311++G (3df, 2p), and the higher level composite CBS–QB3 levels with work reactions that are close to isodesmic in most cases. The enthalpies of formation for CH₃SSOH, CH₃SS(=O)H are ?38.3 and ?16.6 kcal mol^?1, respectively, where the difference is in enthalpy RSO–H versus RS(=O)–H bonding. The C–H bond energy of CH₃SSOH is 99.2 kcal mol^?1, and the O–H bond energy is weaker at 76.9 kcal mol^?1. Cleavage of the weak O–H bond in CH₃SSOH results in an electron rearrangement upon loss of the CH₃SSO–H hydrogen atom; the radical rearranges to form the more stable CH₃SS· = O radical structure. Cleavage of the C–H bond in CH₃SS(=O)H results in an unstable [CH₂SS(=O)H]* intermediate, which decomposes exothermically to lower energy CH₂ = S + HSO. The CH₃SS(=O)–H bond energy is quite weak at 54.8 kcal mol^?1 with the H–C bond estimated at between 91 and 98 kcal mol^?1. Disulfide bond energies for CH₃S–SOH and CH3S–S(=O)H are low: 67.1 and 39.2 kcal mol^?1. Copyright © 2011 John Wiley & Sons, Ltd.     

Correlation of dielectric properties,Raman spectra and calorimetric measurements of β-cyclodextrin-polyiodide complexes (β-cyclodextrin)2 ·BaI7 ·11H2O and (β-cyclodextrin)2 ·CdI7·15H2O

The frequency and temperature dependence of real and imaginary parts of the dielectric constant (ε′,?ε″), the phase shift (?) and the ac-conductivity (σ) of polycrystalline complexes (β-CD)₂·BaI₇·11H₂O and (β-CD)₂·CdI₇·15H₂O (β-CD?=?β-cyclodextrin) has been investigated over the frequency and temperature ranges 0–100?kHz and 140–420?K in combination with their Raman spectra, DSC traces and XRD patterns. The ε′(T), ε″(T) and ?(T) values at frequency 300?Hz in the range T<330?K show two sigmoids, two bell-shaped curves and two minima respectively revealing the existence of two kinds of water molecule, the tightly bound and the easily movable. Both complexes show the transition of normal hydrogen bonds to flip-flop type at 201?K. In the β-Ba complex most of the eleven water molecules remain tightly bound and only a small number of them are easily movable. On the contrary, in the β-Cd case the tightly bound water molecules are transformed gradually to easily movable. Their DSC traces show endothermic peaks with onset temperatures 118°C, 128°C for β-Ba and 106°C, 123°C, 131°C for β-Cd. The peaks 118°C, 106°C, 123°C are related to the easily movable and the tightly bound water molecules, while the peaks at 128°C, 131°C are caused by the sublimation of iodine. The activation energy of Ba²⁺ ions is 0.52?eV when all the water molecules exist in the sample and 0.99?eV when the easily movable water molecules have been removed. In the case of β-Cd the corresponding activation energies are 0.57?eV and 0.33?eV. The Raman peaks at 179?cm^?1, 170?cm^?1 and 165–166?cm^?1 are due to the charge transfer interactions in the polyiodide chains.     

On the role of crystal water in the conduction of synthetic borates

The dispersion of permittivity and conductivity of crystals containing aqua complexes of different types (γ-HBO₂, Ca₂B₆O₁₁ · H₂O, La[B₅O₈]OH)₂ · 1.5H₂O, and TRB₆O₉(OH)₃(TR-Tb, Tu)) is studied for the first time. The compounds were synthesized under hydrothermal conditions at T = 270–280°C and P = 70–100 atm. Depending on the contained aqua complex, the compounds display different temperature and frequency behavior of the electric properties. The measurements are carried out in the frequency range from 10^?2 to 10⁶ Hz and in the temperature range from ?20 to 140°C.     

Hydrogen bond nature in formamide (CYHNH2···XH; YO,S, Se,Te; XF,HO, NH2) complexes at their ground and low‐lying excited states

A theoretical study on the nature of hydrogen bond for formamide and its heavy complexes (CYHNH₂···XH; Y?O, S, Se, Te; X?F, HO, NH₂) was performed on the basis of density functional theory and the quantum chemistry analysis. Except for the CYHNH₂···NH₃ complexes, the substitution of O atom at formamide with less electronegative atoms (S, Se, and Te) is found to weaken the hydrogen bond (H‐bond). This substitution results in cyclic structure of hydrated and ammoniated formamide complexes by the formation of bifunctional H‐bonds (Y···H₄X; X···H₃C). Natural bond orbital analysis indicates that the H‐bond is weakened because of less charge transfer from a lone pair orbital of H‐bond acceptor to antibonding orbital of H‐bond donor. The quantum theory of atoms in molecules analysis reveals that the acyclic structure with single H‐bond stabilizes the complexes more than the cyclic structure formed by bifunctional H‐bonds. Natural energy decomposition analysis (NEDA) and block‐localized wavefunction energy decomposition (BLW‐ED) analyses show that the H‐bond stabilization energies of NEDA and BLW‐ED have good correlation with the dissociation energy of formamide complexes and charge transfer from donor to acceptor atom play an important role in H‐bonding. We have also studied the low‐lying electronic excited states (T₁, T₂, and S₁) for CYHNH₂···H₂O complexes to explore the nature of H‐bond on the basis of electronegativity and found that NEDA also establishes a good correlation with relative electronic energy (with respect to their ground state) and H‐bond strength at their excited states. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and Raman spectroscopy of indium‐based hydrotalcites of formula Mg6In2(CO3)(OH)16· 4H2O

Insight into the unique structure of layered double hydroxides has been obtained using a combination of X‐ray diffraction and Raman spectroscopy. Indium‐containing hydrotalcites of formula Mg₄In₂(CO₃)(OH)₁₂· 4H₂O [2:1 In‐LDH (layered double hydroxides)] through to Mg₈In₂(CO₃)(OH)₁₈· 4H₂O (4:1 In‐LDH) with variation in the Mg : In ratio have been successfully synthesized. The d(003) spacing varied from 7.83 Å for the 2:1 LDH to 8.15 Å for the 3:1 indium‐containing layered double hydroxide. Raman spectroscopy complemented with selected infrared data has been used to characterize the synthesized indium‐containing layered double hydroxides of formula Mg₆In₂(CO₃)(OH)₁₆· 4H₂O. Raman bands observed at around 1058, 1075 and 1115 cm⁻¹ are attributed to the symmetric stretching modes of the CO₃²⁻ units. Multiple ν₃ CO₃²⁻ antisymmetric stretching modes are found at around 1348, 1373, 1429 and 1488 cm⁻¹ in the infrared spectra. The splitting of this mode indicates that the carbonate anion is in a perturbed state. Raman bands observed at 690 and 700 cm⁻¹ assigned to the ν₄ CO₃²⁻ modes support the concept of multiple carbonate species in the interlayer. Copyright © 2010 John Wiley & Sons, Ltd.     

Phonons and electronic transitions in the Raman spectra of FeCl2·2H2O and isomorphic compounds

The Raman spectra in FeCl₂ · 2H₂O (FC2) and the isomorphic compounds FeCl₂ · 2D₂O (FC2D), MnCl₂ · 2H₂O (MC2) and CoCl₂ · 2H₂O (CC2) were observed at 2 K to obtain the frequencies of all 12 optical phonons of even symmetry at the zone center. The lowest of these phonons is known to be coupled resonantly to the magnons below T_N. This coupling and other important magnetic properties of the iron salts are determined by the influence of the crystal field. The electronic transitions of the Fe²⁺-ion in a crystal field are identified after a thorough assignment of the phonon lines in the four isomorphic compounds to symmetry types, using back-scattering and 90°-scattering techniques.     

Raman spectroscopy of gallium‐based hydrotalcites of formula Mg6Ga2(CO3)(OH)16· 4H2O

Insight into the unique structure of hydrotalcites has been obtained using Raman spectroscopy. Gallium‐containing hydrotalcites of formula Mg₄Ga₂(CO₃)(OH)₁₂· 4H₂O (2:1 Ga‐HT) to Mg₈Ga₂(CO₃)(OH)₂₀· 4H₂O (4:1 Ga‐HT) have been successfully synthesized and characterized by X‐ray diffraction and Raman spectroscopy. The d(003) spacing varied from 7.83 Å for the 2:1 hydrotalcite to 8.15 Å for the 3:1 gallium‐containing hydrotalcite. Raman spectroscopy complemented with selected infrared data has been used to characterize the synthesized gallium‐containing hydrotalcites of formula Mg₆Ga₂(CO₃)(OH)₁₆· 4H₂O. Raman bands observed at around 1046, 1048 and 1058 cm⁻¹ are attributed to the symmetric stretching modes of the CO₃²⁻ units. Multiple ν₃ CO₃²⁻ antisymmetric stretching modes are found at around 1346, 1378, 1446, 1464 and 1494 cm⁻¹. The splitting of this mode indicates that the carbonate anion is in a perturbed state. Raman bands observed at 710 and 717 cm⁻¹ assigned to the ν₄ (CO₃²⁻) modes support the concept of multiple carbonate species in the interlayer. Copyright © 2009 John Wiley & Sons, Ltd.     

Selectivity of nitro versus fluoro substitution in arenes in their reactions with charged O‐ and S‐nucleophiles

The relative mobility of nitro and fluoro substituents in 1,3‐dinitro‐ and 1‐fluoro‐3‐nitrobenzenes, 3,5‐dinitro‐ and 3‐fluoro‐5‐nitrobenzotrifluorides under the action of the nucleophiles (2ArYH)·K₂CO₃ and ArY^?K⁺ in solution and the nucleophiles ArYH·K₂CO₃ (Y = O, S) under heterogeneous conditions was studied by a competitive method in DMF at 40–140 °C. The unique dependences of ΔΔH^≠ on ΔΔS^≠ and ΔΔH^≠ on ΔΔG^≠ were determined for all the substrates and nucleophiles. The dependence of the mechanistic pathway on the nucleophile is discussed. Two results are relevant to the reactions studied: (i) substituent effects in the nucleophiles (2ArYH)·K₂CO₃ and ArYH·K₂CO₃ on the activation entropies suggest that the entropy favours the displacement of nitro group; (ii) the negative signs of ΔΔH^≠ and ΔΔS^≠ for the reactions of the nucleophiles ArY^?K⁺ indicate that the enthalpy determines the displacement of nitro group. It is concluded that the selectivity of the reactions with aryloxide and arylthioxide ions cannot be explained by the hard–soft acid–base principle only. Copyright © 2007 John Wiley & Sons, Ltd.     

Evolution of excess electron binding motifs under both internal‐push (from exo C–F bonds) and external‐push (from endo C–F bonds) electron effects in endohedral metallofullerenes with endo C–F bonds

How does the endo C–F bond influence the excess electron binding motif? For lithium‐doped endohedral perfluorofullerenes with endo C–F bonds, under both internal‐push (from exo C–F bonds) and external‐push (from endo C–F bonds) electron effects, the singly occupied molecular orbital electron cloud of the sphere‐like Li···F₈@C₆₀F₅₂ (D₂) is partially dispersed within the σ_p–s antibonding orbital of endo C–F bonds and the space between C^δ+–F_endo^δ– double electric layers, which makes Li···F₈@C₆₀F₅₂ have partial excess electron (electride characteristics) and partial lithium salt characteristics, while in the tube‐like Li···F₂@C₆₀F₅₈ (C_s), as the Li is changing from approaching F to keeping away from F and to approaching another one, the singly occupied molecular orbital electron cloud is mainly dispersed from within the p orbital of the short endo C–F bond to within the middle of the two F atoms and again to within the p orbital of the short endo C–F bond, which indicates an evolution from lithium salt characteristic to excess electron characteristic, and again to lithium salt characteristic. Copyright © 2012 John Wiley & Sons, Ltd.     

Raman Spectra of Alkali and Alkaline Earth Metal Salts of Inosine 5′-Monophosphoric Acid

Crystalline Li(I), Na(I), K(I), Mg(II), Ca(II), Sr(II), Ba(II) and Cd(II) salts of inosine 5′-monophosphoric acid, H₂(IMP), were obtained and characterized by Raman spectroscopy. Splitting of the imidazolic 1480 cm⁻¹ band was observed for the N(7)-bound Ca(IMP)·6H₂O, Ba(IMP)·6H₂O, Sr(IMP)·6H₂O and Cd(IMP)·4H₂O compounds. The Li(I), Mg(II), Ca(II) and Cd(II) ions bind directly to the phosphate group, and no direct coordination involving the carbonyl C(6)O group was observed in the compounds reported here. Some Raman spectral features in the 750–700 cm⁻¹ range seem to reflect the nucleoside structure of the inosine moiety     

Absorptionsspektrum des Ce3+-Ions und Schwingungsspektrum im CeCl3·7H2O und CeCl3·7D2O

The absorption spectra of CeCl₃·7 H₂O, LaCl₃·7 H₂O, CeCl₃·7 D₂O and LaCl₃·7 D₂O have been measured at low temperatures in the region of the 4 f→4 f infrared transitions. The energy levels of the Ce³⁺-ion in these compounds have been derived. The infrared phonon transitions have also been determined from the reflection spectra of these crystals measured in the region between 4000 cm^?1 and 50 cm^?1. Some of the energy levels of the Ce³⁺-ions in the deuterated crystals are shifted for about 10 wavenumbers against those in CeCl₃·7 H₂O. These shifts are probably due to an interaction of the electronic levels with resonant phonon-states in one or the other of the two compounds.