Palladium phthalocyanine and its polymorphic forms

1988 ◽  
Vol 66 (10) ◽  
pp. 2553-2555 ◽  
Author(s):  
Arnold Kempa ◽  
Jan Dobrowolski
Keyword(s):  
Ir Spectra ◽  
Powder Diffraction ◽  
Good Yield ◽  
Ammonium Molybdate ◽  
X Ray ◽  
Nickel Copper ◽  
Polymorphic Forms ◽  
Platinum Phthalocyanine

Pd(II) phthalocyanine (PdPc) was obtained by reaction of PdCl2 with phthalimide and urea in the presence of ammonium molybdate in boiling nitrobenzene, resulting in a good yield equal to 68%. This method has not been used previously. The following polymorphic forms were obtained: metastable α- and γ-PdPc, not previous described in the literature, and stable β-PdPc. The IR spectra and X-ray powder diffraction spectra of these phases were measured and interpreted. The results were compared with the literature data on polymorphic forms of other phthalocyanines. At this time we do not know if any of the PdPc polymorphs are isomorphous with the various forms of nickel, copper, and platinum phthalocyanine.

Application of In-Process X-ray Powder Diffraction for the Identification of Polymorphic Forms during Batch Crystallization Reactions

2004 ◽  
Vol 4 (5) ◽  
pp. 943-948 ◽  
Author(s):  
Robert B. Hammond ◽  
Xiaojun Lai ◽  
Kevin J. Roberts ◽  
Alistair Thomas ◽  
Graeme White
Keyword(s):  
Powder Diffraction ◽  
Batch Crystallization ◽  
X Ray ◽  
Polymorphic Forms

The applicability of powder X-ray diffraction to the quantification of drug substance polymorphs using a model organic system

1993 ◽  
Vol 8 (3) ◽  
pp. 180-187 ◽  
Author(s):  
W. Christopher Kidd ◽  
Peter Varlashkin ◽  
Chia-yu Li
Keyword(s):  
Powder Diffraction ◽  
Drug Substance ◽  
X Ray Diffraction ◽  
Organic System ◽  
Crystal Forms ◽  
X Ray ◽  
Drug Substances ◽  
Polymorphic Forms ◽  
Crystalline System ◽  
Pharmaceutical Production

With a new emphasis on the control of polymorphism in pharmaceutical production, the need for methods to quantify polymorphic forms has arisen. Techniques using X-ray powder diffraction are increasingly being used to characterize the phases of drug substances that exist in multiple crystal forms. Current methods to identify the polymorphic phases in a drug substance include microscopy, infrared spectroscopy, thermal analysis (DSC/TGA), solid state NMR, and X-ray powder diffraction. Of the aforementioned techniques, X-ray powder diffraction provides the most effective approach to identify and quantify the different crystal phases of a pharmaceutical compound. This work is intended as a guide to the characterization and quantification of an organic crystalline system using X-ray diffraction. The approaches suggested are intended to provide assistance not only from an in-process pharmaceutical manufacturing standpoint, but also for routine quality assurance screening of polymorphic drug substances.

Determination of the Polymorphic Forms of Bicifadine Hydrochloride by Differential Scanning Calorimetry—Thermogravimetric Analysis, X-Ray Powder Diffraction, Attenuated Total Reflectance—Infrared Spectroscopy, and Attenuated Total Reflectance—Near-Infrared Spectroscopy

2005 ◽  
Vol 59 (11) ◽  
pp. 1365-1371 ◽  
Author(s):  
Patrick McArdle ◽  
Karen Gilligan ◽  
Desmond Cunningham ◽  
Alan Ryder
Keyword(s):  
Infrared Spectroscopy ◽  
Powder Diffraction ◽  
Density Functional ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
X Ray ◽  
Polymorphic Forms

The pharmaceutical compound bicifadine hydrochloride, which has been found to crystallize in two polymorphic forms, has been characterized by thermal analysis, X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, and near-infrared (NIR) spectroscopy. A series of 22 sample mixtures of polymorph 1 and polymorph 2 were prepared and calibration models for the quantitation of these binary mixtures have been developed for each of the XRPD, attenuated total reflectance (ATR)-IR, and ATR-NIR analytical techniques. The quantitative results were obtained using a partial least squares (PLS) algorithm, which predicted the concentration of polymorph 1 from the XRPD spectra with a root mean standard error of prediction (RMSEP) of 4.4%, from the IR spectra with a RMSEP of 3.8%, and from the NIR spectra with a RMSEP of 1.4%. The studies indicate that when analyses are carried out on equivalent sets of spectra, NIR spectroscopy offers significant advantages in quantitative accuracy as a tool for the determination of polymorphs in the solid state and is also more convenient to use than both the ATR-IR and XRPD methods. Density functional theory (DFT) B3LYP calculations and IR spectral simulation have been used to determine the nature of the vibrational modes that are the most sensitive in the analysis.

scholarly journals X-RAY POWDER DIFFRACTION IN QUALITY CONTROL OF MEDICINES

2018 ◽  
Vol 8 (3) ◽  
pp. 158-161 ◽  
Author(s):  
V. S. Kuzmin ◽  
V. V. Chernyshev ◽  
A. I. Luttseva
Keyword(s):  
Quality Control ◽  
Powder Diffraction ◽  
Biologically Active ◽  
Polymorphic Transformations ◽  
X Ray ◽  
Zolendronic Acid ◽  
Drug Substances ◽  
Rate Of Absorption ◽  
Polymorphic Forms ◽  
Destructive Processes

X-ray powder diffraction is one of the methods used for detection and analysis of polymorphic forms of pharmaceutical substances. The article elucidates the concept of polymorphism, briefly explains physical characteristics of this phenomenon, conditions of polymorphic transformations and the prevalence of polymorphic forms among drug substances. It should be noted that polymorphism is observed in drug substances belonging to different pharmacologic  classes. Polymorphic  forms of the same drug substance have different solubility, melting point,  resistance to oxidation and to other destructive processes, and, consequently, different surface properties which affect both the rate of absorption of the drug substances and their stability as components of dosage forms. This calls for the need to control the quality of drug substances for potential presence of polymorphic forms. The use of diffraction methods for examination of cryomodified forms of various biologically active compounds obtained by evaporation and subsequent precipitation at low temperatures resulted in obtaining polycrystalline substances with new properties. The article provides results of examination of crystalline modifications of phenazepam  in the form of α- and β-polymorphs, tilorone, fabomotizole, zolendronic acid and dehydroepiandrosterone. It was demonstrated that the use of X-ray diffraction analysis for examination and quality control of polymorphic forms of drugs is a necessary component of identification testing.

scholarly journals Synthesis, Molecular Structure from the X-ray Diffraction Data of the Powder (1E,1'E)-1,1'-(1,4-Phenylene)Bis(N-(Adamantan-1-yl)methanimine)

2021 ◽  
pp. 1066-1076
Author(s):  
Shukkur A. Hamed
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Title Compound ◽  
Good Yield ◽  
Chair Conformation ◽  
Parallel Tempering ◽  
X Ray Diffraction ◽  
X Ray

The title compound was synthesized by 2:1 condensation between adamantan-1-ylamine and benzene-1,4- dicarbaldehyde in n-BuOH and produced a good yield 87% of new bis Schiff base. The compound skeleton was affirmed by FTIR, 1H NMR, LC-MS, and X-ray powder diffraction. The structure was solved by a parallel tempering process and refined by using Rietveld refinement. Two adamantan-1-ylimino groups are connected in the anti-positions to the planar central 1,4-dimethylbenzene group. All rings of the adamantyl group possess normal chair conformation.

Solving complex open-framework structures from X-ray powder diffraction by direct-space methods using composite building units

2013 ◽  
Vol 46 (4) ◽  
pp. 1094-1104 ◽  
Author(s):  
A. Ken Inge ◽  
Henrik Fahlquist ◽  
Tom Willhammar ◽  
Yining Huang ◽  
Lynne B. McCusker ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Powder Diffraction ◽  
Unit Cell ◽  
Complex Case ◽  
Asymmetric Unit ◽  
Powder Charge ◽  
Space Group ◽  
X Ray ◽  
Open Framework ◽  
Structure Solution

The crystal structure of a novel open-framework gallogermanate, SU-66 {|(C6H18N2)18(H2O)32|[Ga4.8Ge87.2O208]}, has been solved from laboratory X-ray powder diffraction (XPD) data by using a direct-space structure solution algorithm and local structural information obtained from infrared (IR) spectroscopy. IR studies on 18 known germanates revealed that the bands in their IR spectra were characteristic of the different composite building units (CBUs) present in the structures. By comparing the bands corresponding to Ge—O vibrations in the IR spectra of SU-66 with those of the 18 known structures with different CBUs, the CBU of SU-66 could be identified empirically as the Ge10(O,OH)27 cluster (Ge10). The unit cell and space group (extinction symbol P--a; a = 14.963, b = 31.593, c = 18.759 Å) were determined initially from the XPD pattern and then confirmed by selected-area electron diffraction. The structure of SU-66 was solved from the XPD data using parallel tempering as implemented in FOX [Favre-Nicolin & Černý (2002). J. Appl. Cryst. 35, 734–743] by assuming P21 ma symmetry and two Ge10 clusters in the asymmetric unit. Rietveld refinement of the resulting structure using synchrotron XPD data showed the framework structure to be correct and the space group to be Pmma. The framework has extra-large (26-ring) one-dimensional channels and a very low framework density of 10.1 Ge/Ga atoms per 1000 Å3. SU-66, with 55 framework atoms in the asymmetric unit, is one of the more complicated framework structures solved from XPD data. Indeed, 98% of the reflections were overlapping in the XPD pattern used for structure solution. Tests on other open-framework germanates (SU-62, SU-65, SU-74, PKU-12 and ITQ-37) for which the XPD data, unit cell, space group and IR spectra were available proved to be equally successful. In a more complex case (SU-72) the combination of FOX and powder charge flipping was required for structure solution.

Solid State Characterization and Crystal Structure from X-ray Powder Diffraction of Two Polymorphic Forms of Ranitidine Base

2009 ◽  
Vol 98 (1) ◽  
pp. 146-158 ◽  
Author(s):  
Héctor Novoa de Armas ◽  
Oswald M. Peeters ◽  
Norbert Blaton ◽  
Elke Van Gyseghem ◽  
Johan Martens ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
X Ray ◽  
Polymorphic Forms ◽  
Solid State Characterization

scholarly journals Reactivity of 1,1-DithioIato Ni(II) and Co(II) with Phenylthiourea, Chlorophenylthiourea and Bis(diphenylphosphinothioyl)methane

1987 ◽  
Vol 42 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Aref A. M. Aly ◽  
Mostafa M. Kamal ◽  
Mahmoud S. El-Meligy ◽  
Asma I. El-Said
Keyword(s):  
Biological Activity ◽  
Ir Spectra ◽  
Powder Diffraction ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
X Ray ◽  
Square Planar ◽  
Magnetic Conductivity

Abstract The following mixed ligand complexes were synthesized and characterized: Co(Phdtcz)2(Phtu)2, Co(Phdtcz)2(Clphtu)2 , Co(Phdtcz)2(dtm), Ni(Et2dtc)2(dtm), Ni(Phdtc)2(dtm), Ni(p-Toluiddtc)2(dtm), Ni(α-naphdtc)2(dtm), and Ni(Phdtcz)(Et2dtc); where Phdtcz = phenyldithiocarbazate, Et2dtc = diethyldithiocarbamate, Phdtc = phenyldithiocarbamate, p-Toluiddtc = p-toluidinedithiocarbamate, α-naphdtc = α-naphthyldithiocarbamate, Phtu = phenylthiourea, Clphtu - chlorophenylthiourea, and dtm - bis(diphenylphosphinothioyl)-methane. Electronic and IR spectra, magnetic, conductivity and X-ray powder diffraction measurements were carried out. The Ni(II) and Co(II) complexes are suggested to be square planar and octahedral, respectively. The biological activity of the complexes was also tested.

Analysis of N-(4-Hydroxyphenyl)retinamide Polymorphic Forms by X-ray Powder Diffraction

1984 ◽  
Vol 73 (10) ◽  
pp. 1448-1450 ◽  
Author(s):  
F.A. Chrzanowskix ◽  
B.J. Fegely ◽  
W.R. Sisco ◽  
M.P. Newton
Keyword(s):  
Powder Diffraction ◽  
X Ray ◽  
Polymorphic Forms
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