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Two neodymium(III) six-coordinate complexes NdCl3(3-Br-4-CH3OC7H7NO)3 (Nd1) and Nd(C7H9NO)5(C4H8O2)(ClO4)3 (Nd2) have been synthesized and characterized. The FT-IR and FT-Raman data were acquired, and a complete vibrational assignment of the fundamental modes of the compounds was carried out. The frequencies calculated for the both ligands and scaled using the B3LYP approach with the 6-311G(2d,2p) basis set correspond very well to the experimental values. The XRD results, IR and Raman spectra were discussed in terms of a possible structure and composition of the studied compounds. The optical absorption and emission spectra were investigated at room temperature. The emission decay is mono exponential indicating that the energy transfer from the ligand occurs straight to the 4F3/2 level. The lifetime of this level is about 2.5 μs? A possibility of the energy transfer between the ligands under study and neodymium ions was considered. The calculations of the spin Hamiltonian parameters and EPR data simulation were performed using the electron paramagnetic resonance and nuclear magnetic resonance (EPR-NMR) program.

The crystal structure of the all studied compounds was refined in the monoclinic C2/m ( C 2 h 3 ) space group. The IR and Raman spectra of polycrystalline AgRE(WO4)2 have been recorded and analysed using the factor group approach. In the theoretical considerations the C2/m, P2/c and C2/c unit cell structures were taken into account. The change of the unit cell parameters induced by the RE ions exchange has been analysed. The assignment of the observed bands to the internal and external modes has been proposed. The verification of the structure has been done on the basis of the vibrational behaviour of the studied tungstates. Absorption, emission and excitation spectra of the investigated AgRE(WO4)2 polycrystals have been measured and analysed. The luminescence decay times of 5D0 → 7F2 (Eu3+) and 5D4 → 7F5 (Tb3+) transitions have been calculated.

Na3Ln(PO4)2 orthophosphates (Ln = La, Gd) doped with Er3+ and co-doped with Cr3+ ions were synthesized by Pechini method and characterized by electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. Low temperature EPR spectra were detected and analyzed in terms of temperature dependence and the structure of the obtained materials. They show that erbium and chromium ions substitute Ln3+ and also Na+ ions or Na+ channels forming complex EPR spectra. Both kinds of ions reveal ferromagnetic type of interaction which shows some anomaly at the temperature between 10 K and 15 K. Magnetic susceptibility reveals a weak antiferromagnetic kind of interaction dominating in the whole temperature range, from 3.5 to 300 K.

New europium and terbium [LnCl3L3(H2O)2] polycrystalline complexes were synthesized with the ligand L = 3-bromo-4-methylthio-2,6-lutidine N-oxide. IR, Raman, electron absorption UV-VIS and emission spectra measurements were carried out for these compounds. Re-crystallization of these materials led to formation of single crystals with another composition [LnL(H2O)7]Cl3∙L3, they were characterized by X-ray diffraction technique and spectroscopic measurements. Both types of the materials consist of eight coordinated LnCl3O3O’2 or LnOO’7 polyhedrons containing O - oxygen atoms of the N-oxide group, chlorine atoms or O’ - oxygen atoms of the water units. The crystal structure was solved for two complexes of the formula [Ln(L)(H2O)7]Cl3∙(L)3 where Ln = Eu and Tb. X-ray diffraction analysis reveals that these complexes are isostructural with P21/m space group. The optimization of the molecular system and frequency calculations were carried out using density functional theory (DFT). The DFT quantum chemical calculations of the vibrational wavenumbers were performed for the ligands used for the Eu3+ and Tb3+ ions complexation. The emission measurements were carried out with the femtosecond excitation. The effective ligand-to-metal energy transfer was discovered in the [LnCl3L3(H2O)2] complexes formed in the polycrystalline state.

Room temperature FT-IR spectra in the range 30–4000 cm −1 and FT-Raman spectra in the range 80–4000 cm −1 of indium and lutetium MPX-type phthalocyanines have been compared. The assignment of the observed bands has been accomplished on the basis of DFT chemical calculations using the B3LYP functional and its long range corrected version - CAM-B3LYP. The calculations were carried out for the indium derivative using the LANL2DZ, CC-PVDZ basis sets, i.e. the following approximations were used: B3LYP/CC-PVDZ, B3LYP/CC-PVTZ, B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ and CAM-B3LYP/LANL2DZ. The molecular structures of these derivatives have been discussed in terms of group theory and geometry optimisation taking into account the shape and number of the bands corresponding to the stretching and bending vibrations of MN 4 coordination polyhedron as well as the whole studied complex. The calculated structural parameters have been related to those from XRD studies. The usefulness of the proposed theoretical approaches in the prediction of the structural and vibrational data were analysed.

Sodium-magnesium pentaphosphate with a formula Na 3 Mg 2 P 5 O 16 doped with europium(III) have been synthesized. The concentration of the rare earth ion activators was established to be 1 to 10 at.% in the doped samples. Spectroscopic and structural properties of the obtained samples were investigated by X-ray, Raman, infrared, absorption and luminescence studies. The structure of the studied material was confirmed as monoclinic P2/a = C 2h 4 (No. 13) similar to this described in the literature. The decay times were measured for all samples monitoring the maximum of emission at λ mon = 611 nm and exciting in the 5 L 6 band (λ exc = 396 nm). All decay curves were single exponential and lifetimes remain constant with value τ = 2 ms ± 0.2 ms for the all dopant concentration.

Molecular structures of quercitin and quercitin sulfonic acid have been determined by DFT quantum chemical calculations. FT-IR and FT-Raman spectra have been measured in the solid state and discussed in terms of B3LYP/6-311G(2d,2p) approach. The role of the hydrogen bonds in stabilization of their structures has been analyzed. The IR spectra were measured in the temperature range 5–300 K and the observed effects were used in the discussion of the hydrogen bond behavior.

The lanthanide [Ln(QSA)3(H2O)](H2O)5 complexes in the polycrystalline state and embedded in the silica glass, where Ln = La, Pr, Nd, Eu, Sm, Dy, Er, Gd, Ho, Tb, were studied and characterized using spectroscopic methods. The europium complex was additionally studied theoretically based on the DFT approach which provided molecular structure and electron transition assignment. The emission spectra measured at 293 and 77 K proved the transformation of excitation pulses into the phonon energy. The EPR studies of the Er, Gd, Dy and Sm derivatives were used to determine spin Hamiltonian parameters and g – components. The antiferromagnetic interactions were found and the local monoclinic symmetry of the coordination polyhedron was proposed.

[Ln2(2-hydroxy-5-methyl-nicotinic acid)6(H2O)4] and Ln2(5-methyl-nicotinic acid)6(H2O)4] complexes (Ln = Gd, Tb) have been synthesized and characterized by means of powder X-ray diffraction, IR, Raman, electron UV–Vis and emission measurements. The luminescence and dynamics of the excited states depopulation have been studied using femtosecond laser excitation. The singlet and triplet states of nicotinic acid were localized using DFT quantum chemical calculations. The energy transfer mechanism between the electron levels of the ligands and Tb3+ ion have been proposed.

We report the structural, phonon and luminescence properties of Eu3+-doped Gd3-xEuxNbO7 niobates prepared by conventional solid state reaction. Although a few different crystal structures of pure Gd3NbO7 have been reported so far, their properties still remain controversial and the mechanism of their structural phase transition is not well understood. The temperature-dependent IR and Raman spectra show a structural phase transition occurring at 340 K. The detailed analysis of vibrational spectra and correlation diagrams as well as theoretical factor group considerations allowed us to propose the detailed assignment of the observed bands, define the symmetry of low and high-temperature phases and explain the mechanism of their structural transformation from the Pmcn to the Cmcm centrosymmetric orthorhombic space group. Powder X-Ray diffraction patterns confirm our analysis. The temperature-dependent emission, room-temperature excitation spectra and luminescence decay times are reported to achieve more information on structural and optical properties of the studied niobates.

Na 3 RE(PO 4 ) 2 orthophosphates, where RE = Y and Gd, doped with Yb 3+ ions were synthesised by hydrothermal method and characterised by X-ray diffraction, microscopic, IR and Raman techniques. The emission, excitation spectra were recorded at room temperature and fluorescence decay time was determined. As-synthesised samples crystallise in a trigonal modification and during calcination at 500 °C they transform to a monoclinic or orthorhombic symmetry (for yttrium and gadolinium compounds, respectively). Finally, the samples calcined at 700 °C do not reveal the trigonal symmetry. The morphology of particles for all samples is similar and resembles rice grains. All the obtained for the studied orthophosphates data were compared to those previously reported for the same compounds synthesised by Pechini method.

Na 3 RE (PO 4 ) 2 orthophosphates ( RE = Y, La, Gd) doped with Yb 3+ ions were synthesized by Pechini method and characterized by differential scanning calorimetry/thermogravimetric analysis, X-ray diffraction, IR and Raman spectroscopies as well as optical techniques (emission spectra and fluorescence decay time). All measurements, apart from DSC, were performed at room temperature. The spectroscopic properties were discussed in terms of the structure of the obtained materials. They show that lanthanum and gadolinium phosphates synthesized by Pechini method crystallize in the orthorhombic structure, similar to that of Na 3 Ce(PO 4 ) 2 . For the first time double sodium yttrium orthophosphate has been obtained in monoclinic modification, that could be compared to one of the Na 3 Gd(PO 4 ) 2 polymorph. Annealing of the obtained orthophosphates at 700 °C leads to grain of ∼200 nm. The microstructure of the powders annealed at 700 °C strongly depends on RE 3+ cations.

The electron absorption and emission spectra were measured for the pyramidal LnPc(OAc) complexes in the solid state and co-doped in silica glass, where Ln=Er, Eu and Ho. The theoretical electron spectra were determined from the quantum chemical DFT calculation using four approximations CAM-B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ, B3LYP/LANL2DZ and B3LYP/CC-PVDZ. It was shown that the best agreement between the calculated and experimental structural parameters and spectroscopic data was reached for the CAM-B3LYP/LANL2DZ model. The emission spectra were measured using the excitations both in the ligand and lanthanide absorption ranges. The possibility of energy transfer between the phthalocyanine ligand and excited states of lanthanide ions was discussed. It was shown that the back energy transfer from metal states to phthalocyanine state is responsible for the observed emission of the studied complexes both in the polycrystalline state and silica glass.

Micro-crystalline powders of Na 3 Ce(PO 4 ) 2 orthophosphate doped with Cr 3+ ions were synthesized and characterised by means of X-ray diffraction, IR and Raman, electron absorption, magnetic and EPR studies. The emission and excitation spectra and fluorescence decay time were recorded in the temperature range 70–293 K. The spectroscopic properties of Ce 3+ and Cr 3+ ions in the studied materials were discussed in terms of the structure and local symmetry of the optical ions. These data were compared to those obtained for NaCe(PO 3 ) 4 metaphosphate.

Fourier transform IR and Raman spectra, XRD studies and DFT quantum chemical calculations have been used to characterize the structural and vibrational properties of 2-hydroxy-5-methylpyridine-3-carboxylic acid. In the unit-cell of this compound two molecules related by the inversion center interact via O H⋯N hydrogen bonds. The double hydrogen bridge system is spaced parallel to the (1 0 2) crystallographic plane forming eight-membered arrangement characteristic for pyridine derivatives. The six-membered ring is the second characteristic unit formed via the intramolecular O H⋯O hydrogen bond. The geometry optimization of the monomer and dimer have been performed applying the Gaussian03 program package. All calculations were performed in the B3LYP/6-31G(d,p) basis set using the XRD data as input parameters. The relation between the molecular and crystal structures has been discussed in terms of the hydrogen bonds formed in the unit cell. The vibrations of the dimer have been discussed in terms of the resonance inside the system built of five rings coupled via hydrogen bonds.

The undoped and Cr3+-doped NaCe(PO3)4 metaphosphates were synthesized by the modified Pechini method and obtained as the crystalline powders. They were characterized by means of X-ray diffraction, vibrational and optical spectroscopy to clarify the structure and mechanism of Cr3+ emission in NaCe(PO3)4. This phosphor crystallizes in the monoclinic P121/n1 structure with an infinite (PO3)n chain. The Cr3+ ions can substitute the C1 symmetry site occupied by cerium ions. They can also occupy the tunnels formed in the anionic layer. Spectroscopic properties of the Cr3+ and Ce3+ ions were discussed in terms of structure of the studied crystalline powders. IR and Raman data confirm the predicted structure and indicate C1 site symmetry of the Cr3+ active ions. The Cr3+ ions appear in the distorted octahedral environment of the weak crystal field. Optical studies were confirmed by EPR results carried out in the temperature range of 4–293 K. In addition, the magnetic measurements were performed up to 305 K. The Cr3+ ions reveal negligible ferromagnetic interactions while the Ce3+ ions change their magnetic interactions from slightly antiferromagnetic to significantly ferromagnetic above 20 K.

Fourier transform IR and Raman spectra of the Cd1−3xGd2x□xMoO4 solid solutions have been studied and analysed using the factor group approach (□ denotes the cationic vacancies). The tetragonal I41/a (C4h6) space group with Z = 2 have been applied in the discussion. The assignment of the bands observed to the internal and external modes has been proposed and related to the formation of the solid solutions in which the gadolinium content has been changed in the range 0–1.0. The optical spectroscopic studies show visible dependence of the transition corresponds to the cationic vacancy on the Gd3+ content. The correlation between the crystallographic and spectroscopic data has been discussed in terms of the structural changes of the solid solutions induced by the defects in the CdMoO4 host lattice.

Cadmium-rare earth Cd 0.25 RE 0.5 □ 0.25 MoO 4 molybdates, where RE = Pr–Dy, have been prepared and characterised by powder XRD analysis and spectroscopic studies. IR and Raman spectra at room temperature have been measured in the MIR and FIR ranges. The correlation between the lattice parameters and spectroscopic data has been discussed in terms of factor group analysis. The dependences between the RE 3+ ionic radius, atomic mass and IR and Raman wavenumbers have been discussed.

Neodymium phosphate materials were considered as possible laser media. NaNdP2O7, NaNd(PO3)4, Na3Nd(PO4)2 and Nd3(PO4)O3 phosphates have been synthesized in the solid state reaction protecting the proper conditions characteristic for the each synthesis. Structure, optical properties and vibrational characteristics for the obtained samples have been analyzed taking into account the relations between them. Considering the structure influence of the studied phosphates on their optical properties it was found that the emission efficiency, in that the lifetime in investigated phosphates was not clearly dependent on the type of structure of these materials. Significant improvement of the emission properties is observed only for the NaNd(PO3)4 metaphosphate where the longest Nd–Nd distance appears and the luminescence lifetime of the 4F3/2 level in this material was measured to be 112 μs. It means that among investigated compounds solely NaNd(PO3)4 metaphosphate can be considered as promising stoichiometric laser active material.

The rod- and stick-shaped nanocrystalline cerium and lanthanum orthophosphates, pure and Pr 3+ doped, have been synthesised by the hydrothermal method in acidic (pH 1) or alkaline (pH 11) environment. Subsequent calcination of as-obtained powders at different temperatures, 500 and 900 °C, led to the formation of hexagonal and monoclinic phases, respectively. The hexagonal phase at room temperature has been identified as hydrated orthophosphate with zeolite water inside the channels of the structure. The monoclinic phase is free of water. The average grain size is about 12–30 nm depending on the calcination temperature and preparation conditions. The structural, morphological and optical (vibrational and luminescent) properties have been characterised and their changes due to the temperature and different acidity in the starting materials have been studied.

Room temperature Fourier transform IR and Raman spectra in the range 30–4000 cm−1 and 80–4000 cm−1 of Dy, Ho, Er and Lu phthalocyanide PcLn(OAc)-type complexes have been measured, respectively. The assignment of the bands observed has been made on the literature data. The molecular structure of the PcLnX-type derivatives has been discussed on the basis of the group theory taking into account the shape and number of the bands corresponding to the stretching and bending vibrations of the LnN4O coordination polyhedron as well as whole PcLn(OAc) complex.

Nanocrystals of tripotassium neodymium bis-phosphate(V) doped with ytterbium ions, K3Nd(PO4)2: Yb3+, were synthesized by Pechini method. The obtained grains, having an average size of about 40 nm, were characterised by X-ray, electron microscopic, electron absorption, luminescence and IR studies. Moreover, fluorescence decay studies were carried out at room temperature. The energy transfer from the Nd3+ to Yb3+ was described and discussed. The results were compared to those of the K3Nd(PO4)2 bulk crystal.

Er3+ and Yb3+ doped K3La(PO4)2 ortho- and KLa(PO3)4 metaphosphates were synthesised by the solid state reaction method. The obtained powders were characterised by XRD method, IR and Raman spectroscopy as well as optical absorption spectroscopy. The emission spectra were measured and fluorescence decay studies were carried out at room temperature. The energy transfer from Yb3+ to Er3+ and two-photon up-conversion processes were observed and discussed. The influence of the ortho- and metaphosphate host on efficiency of the luminescence was discussed.

Pechini method has been applied for synthesis of the phosphates in the submicro-state. Dimensions of the obtained grains by this method fall into the 100-1000 nm range. The following samples have been synthesised: stoichiometric orthophosphate Na 3 Ce(PO 4 ) 2 and metaphosphate NaCe(PO 3 ) 4 both doped with 2 and 5% of Eu 3+ . Optical absorption and emission studies have been performed to characterise the properties and structure of the compounds studied. The electronic characteristics of the Ce 3+ and Eu 3+ ions in these materials have been discussed.

New europium complexes of picolinic acid N -oxides have been synthesised and introduced into sol–gel matrices. Their application as UV-light sensors has been considered. The sequence of the electronic levels for Eu 3+ ions has been determined from the absorption and emission studies and assigned to the respective electron transitions. The lifetimes of the excited states have been detected and analysed. The role of the CT transition inside the picolinic ligand and its influence on the ligand to metal charge transfer (LMCT) have been discussed.

The spectroscopic measurements of the calcium niobate CaNb 2 O 6 (columbite) single crystal doped with trivalent praseodymium ions have been performed. The polarised optical absorption and emission spectra as well as luminescence decay curves of this material have been recorded. The absorption spectra consist of well-resolved transitions from the 3 H 4 ground state to the 3 P J , 1 D J , 1 G J , 3 F J and 3 H J levels. The strongest bands correspond to the 3 H 4 → 3 P 0 and 3 H 4 → 3 F 2 transitions. The former band is composed of three components of different intensity. This suggests the existence of three different centers in the CaNb 2 O 6 crystal for the Pr 3+ ions that substitute for Ca 2+ . The emission spectra of the crystal studied show clear temperature and polarisation dependence. The strongest band of the luminescence corresponds to the 1 D 2 → 3 H 4 transition at 610 nm with small bandwidth and high intensity. The lifetime of the 1 D 2 level increases from 59 μs to 78 μs when temperature decreases from 300 K to 50 K.

The results of the FT-Raman and FT-IR studies of the LnCl 3 (LNO) 3 type complexes (where Ln=Pr, Nd, Sm, Eu, Gd, Dy and LNO=3-Br-4-CH 3 OC 7 H 7 NO) are presented. The spectral contours observed in the regions of the lanthanide-oxygen, lanthanide-chlorine and nitrogen-oxygen vibrations are employed in the discussion of the molecular structure of the complex ions and the local symmetry of the LnCl 3 (ON) 3 polyhedron. The discussion of the vibrational spectra is based on the classical normal coordinate analysis and its results are compared to the results of DFT quantum chemical calculations performed for complete molecule. The normal coordinate analysis has been performed for PrCl 3 (ON) 3 and DyCl 3 (ON) 3 molecular systems, which have been treated as a different ‘isotopic units’. Basing on the predominant PED contributions of the respective internal coordinates the assignment of the normal vibrations has been proposed.

Luminescence, luminescence excitation and electronic absorption spectra of europium salts of isomeric lutidine N-oxide derivatives were studied at 293 and 77 K. The role of radiative and non-radiative processes in emission intensity is discussed. The absorption transitions to the 3 F J , 5 D J , 5 L J and 5 G J levels and emissions from the 5 D 0 and 5 D 2 levels were detected. The role of CT transition inside the ligand and its influence on the LMCT transition is analysed. The co-ordinating function of the lutidine N-oxide group is discussed using IR spectroscopy.

A series of six-coordinate complexes of 2,6-lutidine N -oxide (C 7 H 9 NO) with praseodymium, neodymium, samarium, europium, gadolinium and dysprosium has been synthesised and chemically characterised. FT-IR and FT-Raman spectra in the range 80–4000 cm −1 as well as electronic absorption and emission spectra in the range 4000–50,000 cm −1 have been measured. The Lorenzian deconvolution of the vibrational contour in the 100–300 cm −1 region has been used in the discussion of the molecular and site symmetries of the Ln 3+ ion situated in the oxygen polyhedron. The sequence of the electronic levels for all RE ions has been obtained and assigned to the respective transitions.

New praseodymium complexes of 2,6-lutidine, 4-methoxy-2,6-lutidine and 3-halo-2,6-lutidine N -oxides (LuO) have been synthesised and chemically characterised. The Fourier transform IR and Raman spectra have been measured in the range 50–4000 and 80–4000 cm −1 , respectively, and discussed in terms of possible structure and composition of compounds studied. The frequencies of the stretching N–O, Pr–O and Pr–Cl vibrations have been assigned and related to the possible molecular structures of the Pr(LuO) 8 , Pr(LuO) 7 O′, Pr(LuO) 5 O′ 2 O″, Pr(LuO) 6 , PrCl 3 (LuO) 3 and PrCl 3 (LuO) 2 O′ complexes (O′ and O″ denotes the H 2 O and C 2 H 5 OH ligands).

The absence of iodine uptake in metastases of differentiated thyroid carcinoma makes them unresponsive to treatment with radioiodine 131I. In many of such cases symptomatic treatment remains the only available therapy. The results of studies on partial redifferentiation of metastases of thyroid cancer achieved after cis-retinoid acid therapy have drawn attention to the possibility of restoration of iodine uptake in metastases after pretreatment with cis-retinoic acid (Roaccutane). 5 patients with iodine uptake-negative metastases of differentiated thyroid carcinoma were given Roaccutane in a dose 1.5 mg/kg/24 h daily for 6 weeks before the therapy with radioiodine. In none of the patients restoration of radioiodine uptake in metastases has occurred as shown in post-therapeutic total body scintigraphy.

Hypoparathyroidism remains a serious complication of total thyroidectomy for differentiated thyroid carcinoma (DTC). In Brachytherapy Department 952 patients affected with DTC were followed up in the years 1996-2000. Radical total thyroidectomy was performed in 235 (24.6%) of cases, while the other 717 patients underwent complete rethyroidectomy. The incidence of hypoparathyroidism following radical operation and after complete rethyroidectomy was 15.74% and 23.43%, respectively. In patients operated in our institution, blood for calcium was analyzed daily for five days following the surgery. If calcium level was normal the next measurement was performed 4-5 weeks thereafter. Hypoparathyroidism was diagnosed later in postoperative period in many patients operated elsewhere. Asymptomatic hypocalcemia during the first week after the operation requires oral administration of calcium. If hypocalcemia requiring intravenous calcium supplementation does not resolve in a few days, vitamin 1(OH)D3 is introduced. Vitamin 1(OH)D3 and calcium carbonate play the main role in management of persistent hypocalcemia. In case of marked hypercalciuria thiazid diuretics are instituted. Low-phosphate diet is recommended. The aim of treatment of hypoparathyroidism is to restore normal serum calcium level with calciuria not exceeding 5 mg/kg/24 h, so to avoid hypocalcemic complications as well as vitamin D intoxication.

A new very promising red phosphor KCa1-xEux(PO3)3 (x = 1-5%) has been grown by the solid state method. Its luminescent quantum efficiency is close to 100% and the emission is stable over a wide temperature range i.e. 90% and 60% of the room temperature emission intensity remains at 200 °C and at 600 °C, respectively. The chromaticity coordinates were calculated as being x = 0.63, y = 0.37. The IR and Raman spectra were measured, and the maximum phonon energy of KCa1-xEux(PO3)3 is 1276 cm(-1). In the measured emission and excitation spectra of all samples only Eu(3+) ion emission was observed, emission of Eu(2+) is not present. Quantum mechanical calculations showed that in a perfect crystal the 5d levels of Eu(2+) are embedded in the conduction band. Consequently, neither absorption nor emission assigned to the Eu(2+) ions could be observed. The presence of a calcium vacancy is crucial for the explanation of the observed spectrum. The existence of a Ca(2+) vacancy compensates for the charge of Eu(3+) and results in the creation of the magnetic moment which moves the 4f levels to the valence band. Thus, transitions to the Eu(3+) excited levels located in the energy band gap are observed.