scholarly journals Solvate Formation of Bis(demethoxy)curcumin: Screening and Characterization

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 407 ◽  
Author(s):  
Lina Yuan ◽  
Heike Lorenz
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Mass Loss ◽  
Storage Conditions ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
X Ray ◽  
Ambient Storage

Solvate formation of bis(demethoxy)curcumin (BDMC) was screened. Six solvates were obtained out of the nineteen solvents investigated. In the present work, three solvates, i.e., BDMC-tetrahydrofuran (THF), BDMC-1,4-dioxane (DIO) and BDMC-dimethyl sulfoxide (DMSO), were thoroughly studied. Their desolvation processes were characterized by temperature-resolved powder X-ray diffraction (TR-PXRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and hot-stage microscopy (HSM). TR-PXRD shows that all the solvates desolvate as the mother BDMC form and no new polymorph could be obtained. The stoichiometric ratio of solvates was calculated via the mass loss of solvents determined by TGA. The thermal stabilities of the solvates were obtained from DSC data and followed the order: BDMC-DMSO > -THF > -DIO. Moreover, stability performances at ambient storage conditions recorded by PXRD show that BDMC-DMSO was stable over three months.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

scholarly journals COCRYSTALS: A COMPLETE REVIEW ON CONVENTIONAL AND NOVEL METHODS OF ITS FORMATION AND ITS EVALUATION

2019 ◽  
pp. 68-74
Author(s):  
BIJAY KUMAR YADAV ◽  
ATIF KHURSHEED ◽  
RATTAN DEEP SINGH
Keyword(s):  
Differential Scanning Calorimetry ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Drug Molecule ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cooling Crystallization ◽  
Active Moiety ◽  
Single State ◽  
As Solubility

The active moiety with poor solubility is posing a challenge in drug development which may reduce the effectiveness in patients when administered orally. Cocrystal formation is one of the latest approaches for improving the various parameters of a drug molecule such as solubility, melting point, pharmacokinetic, pharmacodynamic, and bioavailability. Cocrystals are crystalline single state materials composed of two or more than two different molecular amalgams held together in a fixed stoichiometric ratio. There are various techniques used for the preparation of cocrystals such as solvent evaporation, grinding, and cooling crystallization. The quantitative and qualitative aspects of these cocrystals are evaluated using various validated instruments such as nuclear magnetic resonance, powder X-ray diffraction, and differential scanning calorimetry.

scholarly journals Synthesis, Crystal structures, and Thermal behaviors of MBTO·nPhen with M=Co, Ni, Cu, Zn and Phen=1,10-Phenanthroline

2019 ◽  
Author(s):  
Jiaping Zhu ◽  
Xiaoqing Yao ◽  
Gang Wang ◽  
Jianfeng Ban ◽  
Dang Wu ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Sandwich Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Straightforward Manner ◽  
Thermal Stabilities ◽  
Exponential Factor ◽  
X Ray ◽  
Metal Atoms ◽  
Apparent Activation Energies

The cocrystal of 1,10-phenanthrolin-1-ium 1-hydroxy-[5,5'-bitetrazol]-1'-olate (BTO·Phen) from 5,5′-bistetrazole-1,1′-diol dehydrate (BTO) and 1,10-Phenanthroline (Phen) was synthesized in a simple, straightforward manner and was characterized by IR, elemental analysis, and single-crystal X-ray diffraction of several salts (Ni2+ and Zn2+) were also given. The X-ray structures show that in the title compounds, the metal atoms are bonded to the nitrogen atom in the Phen ring and the oxygen atom in the bistetrazole ring to form the sandwich structure. Thermal stabilities of all title compounds were determined with Differential scanning Calorimetry (DSC), showing good thermostability. In addition, thermokinetic parameters including the apparent activation energies (E K and E O) and pre-exponential factor (A) were also calculated.

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