Synthesis and Quantum Chemistry Studies of (R)-N-(Propionylthiazolidine-2-thione-4-methoxycarbonyl)germanium Sesquioxide

(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which shown that the >CO and >CS groups are located in the opposite sides of C(4)—N—C(3) bond with transconfiguration. The electronic structures and optimized configurations of compounds 1 and 2 were studied with MNDO method.

Studies on the Interaction of Novel Organogermanium Sesquioxides with DNA

The affinity and mode of interaction of four novel organogermanium sesquioxides with calf thymus DNA（CT-DNA） and two synthetic oligonucleotides, d（AT）22d（AT）22 and d（GC）22d（GC）22, were investigated by a combination of absorption spectroscopy, DNA thermal denaturalization method, viscosity method, fluorometric technique, and competitive binding study with ethidium bromide（EB）. The results show that the organogermanium compounds can interact with DNA by intercalation, the binding ability of the compounds to CT-DNA and the synthetic oligonucleotides was found to be modest（in comparison to the proven intercalators）, With binding constants on the order of 10^3-10^5 L/mol, respectively. Generally, the binding of the organogermanium sesquioxides with naphthalene moiety to DNA is stronger than that of the compounds with anthraquinone moiety. And the compounds with anthraquinone moiety have preference for binding to AT-rich duplexes, whereas the compounds with naphthalene moiety have a little preference for binding to GC-rich duplexes. DNA may be the primary effect target.

Optimization of the gain in Yb^(3+)-doped cubic laser crystals of 99.99% purity

This was an outlook on the prediction of the infrared laser potentiality from concentration dependences of the 2F5/2 experimental decay time in Yb3＋-doped solid-state crystals mainly on cubic crystals with 99.99% purity which could be extended to laser ceramics of the same composition.

Synthesis of RE(OH)_2Cl and REOCl (RE=Eu, Tb) nanostructures

Anisotropic structures, nanoneedles, and nanospindles of rare earth hydroxychloride （RE（OH）2Cl） and oxychloride （REOCl） （rare earth=Eu and Tb） were synthesized. The rare earth hydroxychloride nanostructures were formed via a thermally assisted hydrolysis of the rare-earth sesquioxide nanocrystals. The morphological evolution of the nanostructures was studied using high-resolution transmission electron microscopy and scanning electron microscopy, while the structural evolution was investigated using X-ray diffraction techniques. The thermal stability of the rare earth hydroxychlorides was investigated using thermogravimetric analysis. The rare earth oxychloride nanospindles were synthesized via a simple heat-treatment of rare earth hydroxychloride nanospindles.

Assessment of Dithionite and Oxalate Extractable Iron and Aluminium Oxides on a Landscape on Basement Complex Soil in South-Western Nigeria

The study investigats the morphological, physical and chemical characteristic of a toposequence on basement complex in Ejioku area, south-western Nigeria on latitude 07°28.675'N;and longitude 004°07.219'E;180 m above sea level at the upper slope. It terminates at the valley bottom on latitude 07°28.756'N;and longitude 004°07.229'E;175 m above sea level. The topography of the site is moderately slope (not greater than 10%). The aim is to examine the two forms of sesquioxides (crystalline-dithionite extractible Fe & Al and amorphous-oxalate Fe & Al) and their distribution on the toposequence. The crystalline form of Fe oxide dominates all the positions and ranges from 7.2 g/kg at the valley bottom to 444.3 g/kg at the crest compared to the amorphous forms that range from 2.7 g/kg to 10.9 g/kg. The crystalline and amorphous aluminium oxide contents of the soils are low (2.9 g/kg - 43.3 g/kg and 1.3 g/kg - 8.7 g/kg respectively). There is significant negative relationship between Fed and Fed/Feo (r =-0.15;P n = 16). There is also a correlation between Feo and Ald (r = 0.63;P n = 16), FeO and FeO/Fed (r = 0.44;P n = 16), signifying a high level of weathering. The relatively high amount of Fed virtually at all the horizons indicates that the crystalline and less active forms of the oxides exist more on the landscape and may be responsible for the non-availability of some nutrient like phosphorus that may be sorbed to their crystals lattice. All forms of Al in the soils are low especially, the oxalate extractable forms, when compare with the dithionite extractable forms. However, there is a significant correlation between Ald and Feo/Fed (r = 0.57;P < 0.01). As a result of high accumulation of crystalline form of Fe and Al oxide with increasing depth, most especially, at the crest/upper slope, there is greater amount of concretions, nodules and plinthites which will lead to further deterioration of the soil for agricultural purposes.

Multiphonon-assisted continuous-wave tunable vibronic laser in Yb:LuScO_(3)crystal

In this work,we demonstrate the phonon-assisted vibronic lasing of a Yb-doped sesquioxide Yb:LuScO_(3)crystal.The electron–phonon coupling process was analyzed and the Huang-Rhys factor S was calculated to be 0.75 associated with the fluorescence spectrum at room temperature.By a rational cavity design to suppress lasing below 1100 nm,a continuously spectral tunability from 1121 to 1136 nm was realized in a Yb:LuScO_(3)laser,which represents the longest achievable wavelength in the Yb-doped sesquioxide lasers.Moreover,the Raman spectrum indicated that the Egphonon mode with a frequency of 472 cm^(-1)was mainly devoted to the phonon-assisted transition process.This work broadens the achievable laser spectrum of Yb-doped sesquioxide,and suggests that the multiphonon–electron coupling strategy should be universal for other laser materials.

Raman spectra of RE_2O_3(RE=Eu,Gd,Dy,Ho,Er,Tm,Yb,Lu,Sc and Y): laser-excited luminescence and trace impurity analysis

Raman spectra of a series of cubic rare earth sesquioxides RE2O3 （RE=Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y） were investigated by Raman spectroscopy with both 532 and 785 nm laser lines. Abundant additional bands due to laser-excited lumines-cence were observed. For Eu2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3 and Yb2O3, the luminescence mainly came from the intrinsic trivalent lanthanide ions, while for Gd2O3, Lu2O3, Sc2O3 and Y2O3, their luminescence were attributed to the trace impurities of other lumines-cent lanthanide ions such as Eu3＋, Nd3＋and Er3＋. This investigation confirmed Raman spectroscopy as a useful tool for detecting trace luminescent lanthanide impurities.

Fabrication and comprehensive structural and spectroscopic properties of Er:Y_(2)O_(3)transparent ceramics

Transparent Er:Y_(2)O_(3)ceramics with sub-micron grain size(<1μm)were fabricated by using one-step vacuum sintering followed by hot isostatic pressing(HIPing)technique.The transmission of the undoped Y_(2)O_(3)reaches 83%.The structural characteristics including the phonon energy were investigated through X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)analysis and scanning electron microscopy(SEM)measurement.The overall spectroscopic properties of transmission,fluorescence emission up to 3000 nm,lifetime,up-conversion luminescence,and refractive index were systematically studied for both 0.25 at%and 7.0 at%Er:Y_(2)O_(3)ceramics with different thicknesses.The comparison of the spectra of the fluorescence emission and up-conversion luminescence under both 976 and 808 nm laser excitation was performed.The multiple high-energy-state transitional processes after the excited state absorption(ESA)processes involved in the up-conversion are discriminated between the multi-phonon non-radiative transitions and the radiative transitions according to the measured maximum phonon vibrational energy.The calculation was performed based on the Judd-Ofelt theory.