Structure-resolvability relationship of several diastereomeric salt pairs of 1-phenylethylamine - A Cambridge Structural Database study

In order to study the effects of crystal structures on resolvability, a CSD (Cambridge Crystallographic Database) study has been carried out on 1-phenylethylammonium diastereomeric salt pairs with available crystal structures. The structures of the diastereomers of the salts are analyzed, compared and grouped. The structural features are set against the resolution results. The effects of three types of structural features on the resolution efficiency are demonstrated

In situ Evolved Gas Analysis of TMOS-based Gel Electrolytes Containing Guanidinium Thiocyanate for Quasi-solid-state Dye-sensitized Solar Cells by TG-FTIR and TG-MS

A comparative study on thermal stability of hybrid (organic / inorganic) electrolytes for dye-sensitized solar cells (DSSCs) in various ethylene oxide oligomers / silica based gelly matrices, containing also some efficiency-promoter additives is presented. Using thermogravimetry combined with two evolved gas analytical (EGA-FTIR and EGA-MS) techniques, the released gases and volatile decomposition products from the composite electrolytes during dynamic heating programs have been identified and monitored. First methanol (arising from condensation of tetramethoxysilane, TMOS) and acetonitrile (solvent) are evolved followed by elongated release of 4-tert-butylpyridine, than carbonyl sulfide, which is one of the degradation products of guanidinium thiocyanate, and various alkyl iodides, as well as iodine, later various oxidized species with >C=O groups (arising from oxidative degradation of oligo(ethylene glycolic) parts, ammonia (originated from guanidine) have been observed and traced during the accelerated heating tests, before final burning out of the organic residue with CO2 evolution. Thermal behavior of pure guanidinium thiocyanate, one of the most important additives improving thermal stability of Grätzel type solar cells (DSSCs), combined with identification of its eight gaseous decomposition products and their release pattern is also reported

Kapcsolt termoanalitikai módszerek vékony filmek technológiájának fejlesztésében

A termikus analízis, amelynek Magyarországon is nagy hagyományai vannak,1,2 leggyakrabban porított, ill. aprított formájú analitikai mintákat vizsgál. Azonban a termoanalitikai technikák és mérőberendezések, jelenlegi magas összetettségi szintjüknek köszönhetően már ma is képesek vizsgálni olyan hőmérséklet indukálta változásokat, amelyek vékony fi lmekben jelennek meg, ahol a rendelkezésre álló mintamennyiség csekély, rendszerint 1 mg/cm2 alatt van. Ez kiszélesíti a termikus analízis alkalmazhatósági körét a vékonyfi lm-technológiához, mely kulcsszerepet játszik új anyagok, folyamatok és eszközök kifejlesztésében, különösen a mikroelektronikai és optoelektronikai ipar számára. 3,4 Egyik nem túl régi példája a mind vékony rétegek mind porok formájában igen jelentős alkalmazási potenciállal bíró új anyagoknak a magas hőmérsékletű szupravezetők. A termikus analízist ezen új oxidkerámia anyagok tanulmányozására már rögtön a felfedezésük után alkalmazni kezdték, és különösen a szupravezetők szintézisében és a kívánatos oxigéntartalmuk, ill. oxigénsztöchiometriájuk jellemzésére a termoanalitikai módszerek elengedhetetleneknek bizonyultak.5-7 Általában elmondható, hogy a termikus analízis most válik azon technikáknak az egyik gyakran használt csoportjává, amelyek képesek problémamegoldásra a vékonyfi lmek formájában leválasztásra és jellemzésre kerülő anyagok körében. A termikus analízis megnövekedett használatának egyik oka, többek között, a vékony fi lmek kémiai leválasztási módszereinek a mind gyakoribb alkalmazása, amelyek során a prekurzoranyagok és leválasztás kémiai folyamatai kényelmesen tanulmányozhatók a termikus analízis eszközeivel

Crystalline Forms of 4,4'-Methylenediantipyrine: Crystallographic Unit Cell for the Anhydrous Form, from Laboratory Powder XRD Pattern by DASH Program Package

Crystalline unit cell structure of anhydrous title compound, diantipyrinylmethane (CAS Registry No. 1251-85-0), a substance usually obtained as a by-product in Mannich type reactions of antipyrine, has been modelled by the help of powder X-ray diffraction, applying the DASH software package and crystal coordinates coming from former single crystal X-ray structure determinations (CSD codes FADDIY and FADDIY01) of its monohydrate. The unit cell of the anhydrate compound belongs to the monoclinic space group P21/a, with unit cell parameters of a = 14.604, b = 9.858, c = 14.509 Å, β = 95.56 °, V = 2078.9 Å3, Z = 4, Z ' = 1. Comparisons of FT-IR spectrum and thermal behavior of the anhydrous and monohydrated forms confirm differences in degree of hydration and solid state structure, while those of 1H- and 13C NMR-spectra show their molecular identity

Effect of Different Anions Upon the WO3 Morphology and Structure

In this study the effects of various anions (SO42-, ClO4- and PO43-) were investigated on the hydrothermal treatment of WO3 from Na2WO4 and HCl at 180 and 200 degrees C. The products were analyzed by XRD and SEM. With the usage of SO42- the obtained product was hexagonal (h-) WO3 in the form of nanorods at both temperatures. Applying ClO4- resulted in a mixture of WO3 center dot 0.33H(2)O and small amount of m-WO3 at 180 degrees C and pure WO3 center dot 0.33H(2)O at 200 degrees C. The morphology was consisted of cuboid shapes arranged into spherical structures at 180 degrees C and longitudinal ones at 200 degrees C. By the application of PO43- no product formed at either temperature. Using the combination of SO42-, and ClO4- the product was h-WO3 at both 180 and 200 degrees C with rod-like crystals; thus, the effect of ClO4- was overdominated by the SO42- ions. Utilization of PO43- together with SO42-, and/or ClO4- resulted again in no product, meaning that adding PO43- to the reaction mixture completely blocks the hydrothermal formation of solid products by forming water soluble phosphotungstic acids