1
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Hodgkinson P. NMR crystallography of molecular organics. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 118-119:10-53. [PMID: 32883448 DOI: 10.1016/j.pnmrs.2020.03.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 02/25/2020] [Accepted: 03/13/2020] [Indexed: 06/11/2023]
Abstract
Developments of NMR methodology to characterise the structures of molecular organic structures are reviewed, concentrating on the previous decade of research in which density functional theory-based calculations of NMR parameters in periodic solids have become widespread. With a focus on demonstrating the new structural insights provided, it is shown how "NMR crystallography" has been used in a spectrum of applications from resolving ambiguities in diffraction-derived structures (such as hydrogen atom positioning) to deriving complete structures in the absence of diffraction data. As well as comprehensively reviewing applications, the different aspects of the experimental and computational techniques used in NMR crystallography are surveyed. NMR crystallography is seen to be a rapidly maturing subject area that is increasingly appreciated by the wider crystallographic community.
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Affiliation(s)
- Paul Hodgkinson
- Department of Chemistry, Durham University, Stockton Road, Durham DH1 3LE, UK.
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2
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Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron. CRYSTALS 2020. [DOI: 10.3390/cryst10030157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Nicosulfuron (NS) is a widely used sulfonylurea herbicide because of its high selectivity, broad spectrum of herbicide activity, and excellent performance. In this work, nicosulfuron methanol solvate (NS-MeOH) and [[3-[(Dimethylamino)carbonyl]-2-pyridinyl]sulfonyl]carbamic acid methyl ester (PCM) as a product of methanolysis of NS were obtained. Both of their structures were determined by a single crystal X-ray diffraction. A broad range of analytical techniques was applied to characterize the NS-MeOH, such as Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and hot stage microscopy (HSM). Combined with the analysis of the Independent gradient model (IGM), Atom-in-molecules (AIM), and Hirshfeld surface (HS), direct insights into the role of solvent played in the formation of NS-MeOH and the mechanism of solid-to-solid phase transformation of NS-MeOH could be obtained. In addition, the aqueous solubility of NS was improved through the formation of NS-MeOH. A systematic investigation of herbicidal activity of NS and PCM was carried out. It was found that NS and NS-MeOH had similar herbicidal activities at the experimental concentrations while PCM exhibited significantly lower activity. It was suggested that methanolysis of the sulfonylurea bridge in the NS molecule exerted a great influence on the herbicidal activity.
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3
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Widdifield CM, Farrell JD, Cole JC, Howard JAK, Hodgkinson P. Resolving alternative organic crystal structures using density functional theory and NMR chemical shifts. Chem Sci 2020; 11:2987-2992. [PMID: 34122800 PMCID: PMC8157514 DOI: 10.1039/c9sc04964a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Alternative (‘repeat’) determinations of organic crystal structures deposited in the Cambridge Structural Database are analysed to characterise the nature and magnitude of the differences between structure solutions obtained by diffraction methods. Of the 3132 structure pairs considered, over 20% exhibited local structural differences exceeding 0.25 Å. In most cases (about 83%), structural optimisation using density functional theory (DFT) resolved the differences. Many of the cases where distinct and chemically significant structural differences remained after optimisation involved differently positioned hydroxyl groups, with obvious implications for the correct description of hydrogen bonding. 1H and 13C chemical shifts from solid-state NMR experiments are proposed as an independent methodology in cases where DFT optimisation fails to resolve discrepancies. DFT optimisation often resolves conflicting crystal structure determinations, with NMR shifts helping in cases where optimisation diverges to different structures.![]()
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Affiliation(s)
- Cory M Widdifield
- Department of Chemistry, Oakland University 146 Library Drive Rochester MI 48309-4479 USA
| | - James D Farrell
- Institute of Physics, Chinese Academy of Sciences Beijing 100190 People's Republic of China
| | - Jason C Cole
- Cambridge Crystallographic Data Centre 12 Union Road Cambridge CB2 1EZ UK
| | - Judith A K Howard
- Department of Chemistry, Durham University Stockton Road Durham DH1 3LE UK
| | - Paul Hodgkinson
- Department of Chemistry, Durham University Stockton Road Durham DH1 3LE UK
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4
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Camacho PS, Stanford MW, McKay D, Dawson DM, Athukorala Arachchige KS, Cordes DB, Slawin AMZ, Woollins JD, Ashbrook SE. Polymorphism, Weak Interactions and Phase Transitions in Chalcogen-Phosphorus Heterocycles. Chemistry 2018; 24:11067-11081. [PMID: 29791041 PMCID: PMC6099295 DOI: 10.1002/chem.201800978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Indexed: 01/03/2023]
Abstract
A series of P-E-containing heterocycles (E=chalcogen) with aromatic backbones were synthesised and characterised by single-crystal and powder XRD, microanalysis and mass spectrometry. Solution- and solid-state 31 P and 77 Se NMR spectroscopy revealed significant differences between the NMR parameters in solution and in the solid state, related to conformational changes in the molecules. Many compounds were shown to exhibit a number of different polymorphic structures (identified by single-crystal XRD), although the bulk material studied by solid-state NMR spectroscopy often contained just one major polymorph. For the unoxidised heterocycles, the presence of weak intermolecular J couplings was also investigated by DFT calculations.
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Affiliation(s)
- Paula Sanz Camacho
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - Martin W. Stanford
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - David McKay
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - Daniel M. Dawson
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | | | - David B. Cordes
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - Alexandra M. Z. Slawin
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - J. Derek Woollins
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
| | - Sharon E. Ashbrook
- School of Chemistry and EaStCHEM and Centre of Magnetic ResonanceUniversity of St AndrewsSt Andrews, FifeKY16 9STUK
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5
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Savchenkov AV, Serezhkin VN. A method for visualization of the variation of noncovalent interactions in crystal structures of conformational polymorphs. ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS 2018; 74:137-147. [DOI: 10.1107/s2052520618001348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 01/22/2018] [Indexed: 11/11/2022]
Abstract
A method for clear visualization of the variation of noncovalent interactions in crystal structures of conformational polymorphs is developed and introduced. The first stage of the method establishes the characteristics of all, without exception, noncovalent interactions in all crystal structures under discussion. This is possible using a strict and objective method of construction of Voronoi–Dirichlet polyhedra within the framework of the stereoatomic model of crystal structures. The second stage of the method then involves plotting of diagrams, showing the relation between parameters characterizing interatomic interactions and chosen geometric parameters of molecules. Application of the title method to highly polymorphic systems of ROY and flufenamic acid allows several imperceptible features of real crystal structures to be revealed and determines the value of different types of interactions in their conformational polymorphs. The method is universal as it can be readily adapted to any system of crystal structures in which noncovalent interactions change as a function of any parameters. Employment of the title method along with quantum chemical calculations offers opportunities for the correlation of potential energy of crystalline materials with noncovalent interactions in their structures, which is a giant step forward towards a more complete understanding of the relationship between the structure and properties of compounds.
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6
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Abstract
Interest in molecular crystals has grown thanks to their relevance to pharmaceuticals, organic semiconductor materials, foods, and many other applications. Electronic structure methods have become an increasingly important tool for modeling molecular crystals and polymorphism. This article reviews electronic structure techniques used to model molecular crystals, including periodic density functional theory, periodic second-order Møller-Plesset perturbation theory, fragment-based electronic structure methods, and diffusion Monte Carlo. It also discusses the use of these models for predicting a variety of crystal properties that are relevant to the study of polymorphism, including lattice energies, structures, crystal structure prediction, polymorphism, phase diagrams, vibrational spectroscopies, and nuclear magnetic resonance spectroscopy. Finally, tools for analyzing crystal structures and intermolecular interactions are briefly discussed.
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Affiliation(s)
- Gregory J O Beran
- Department of Chemistry, University of California , Riverside, California 92521, United States
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7
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Veinberg SL, Johnston KE, Jaroszewicz MJ, Kispal BM, Mireault CR, Kobayashi T, Pruski M, Schurko RW. Natural abundance 14N and 15N solid-state NMR of pharmaceuticals and their polymorphs. Phys Chem Chem Phys 2016; 18:17713-30. [DOI: 10.1039/c6cp02855a] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
14N and 15N solid-state NMR at natural abundance are used in tandem for the investigation of pharmaceuticals and their polymorphs.
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Affiliation(s)
| | | | | | - Brianna M. Kispal
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
| | | | | | - Marek Pruski
- U.S. DOE Ames Laboratory
- Iowa State University
- Ames
- USA
- Department of Chemistry
| | - Robert W. Schurko
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
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8
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Harty EL, Ha AR, Warren MR, Thompson AL, Allan DR, Goodwin AL, Funnell NP. Reversible piezochromism in a molecular wine-rack. Chem Commun (Camb) 2015; 51:10608-11. [DOI: 10.1039/c5cc02916c] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Coupling of a ‘wine-rack’ lattice motif with molecular flexibility leads to a large piezochromic response in an organic material.
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Affiliation(s)
- Elena L. Harty
- Department of Chemistry
- University of Oxford
- Inorganic Chemistry Laboratory
- Oxford OX1 3QR
- UK
| | - Alex R. Ha
- Department of Chemistry
- University of Oxford
- Inorganic Chemistry Laboratory
- Oxford OX1 3QR
- UK
| | | | - Amber L. Thompson
- Department of Chemistry
- University of Oxford
- Inorganic Chemistry Laboratory
- Oxford OX1 3QR
- UK
| | | | - Andrew L. Goodwin
- Department of Chemistry
- University of Oxford
- Inorganic Chemistry Laboratory
- Oxford OX1 3QR
- UK
| | - Nicholas P. Funnell
- Department of Chemistry
- University of Oxford
- Inorganic Chemistry Laboratory
- Oxford OX1 3QR
- UK
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9
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Carletta A, Dubois J, Tilborg A, Wouters J. Solid-state investigation on a new dimorphic substituted N-salicylidene compound: insights into its thermochromic behaviour. CrystEngComm 2015. [DOI: 10.1039/c5ce00283d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solid-state polymorphism behaviour of a new thermochromic mechanosynthesized compound derived from ortho-vanillin is investigated through SCXRD and ab initio prediction methods.
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Affiliation(s)
- A. Carletta
- Unité de Chimie Physique
- Théorique et Structurale
- Chemistry Department
- University of Namur
- B-5000 Namur, Belgium
| | - J. Dubois
- Unité de Chimie Physique
- Théorique et Structurale
- Chemistry Department
- University of Namur
- B-5000 Namur, Belgium
| | - A. Tilborg
- Unité de Chimie Physique
- Théorique et Structurale
- Chemistry Department
- University of Namur
- B-5000 Namur, Belgium
| | - J. Wouters
- Unité de Chimie Physique
- Théorique et Structurale
- Chemistry Department
- University of Namur
- B-5000 Namur, Belgium
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10
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Silva PA, Maria TM, Nunes CM, Eusébio MES, Fausto R. Intermolecularly-induced conformational disorder in ferrocene, 1-bromoferrocene and 1,1′-dibromoferrocene. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2013.12.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Zielińska-pisklak M, Pisklak DM, Wawer I. Application of 13C CPMAS NMR for Qualitative and Quantitative Characterization of Carvedilol and its Commercial Formulations. J Pharm Sci 2012; 101:1763-72. [DOI: 10.1002/jps.23062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 12/10/2011] [Accepted: 01/04/2012] [Indexed: 11/12/2022]
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12
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Wang WD, Gao X, Strohmeier M, Wang W, Bai S, Dybowski C. Solid-State NMR Studies of Form I of Atorvastatin Calcium. J Phys Chem B 2012; 116:3641-9. [DOI: 10.1021/jp212074a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wei David Wang
- State Key Laboratory of Applied
Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Xudong Gao
- State Key Laboratory of Applied
Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Mark Strohmeier
- Product Development, GlaxoSmithKline, Inc., 709 Swedeland Road, King of
Prussia, Pennsylvania 19406, United States
| | - Wei Wang
- State Key Laboratory of Applied
Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Shi Bai
- State Key Laboratory of Applied
Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, China
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United
States
| | - Cecil Dybowski
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United
States
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13
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Polymorphic and kinetic investigation of adefovir dipivoxil during phase transformation. Int J Pharm 2012; 422:185-93. [PMID: 22079719 DOI: 10.1016/j.ijpharm.2011.10.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 10/24/2011] [Accepted: 10/27/2011] [Indexed: 11/21/2022]
Abstract
To search polymorphs of adefovir dipivoxil (AD), the polymorphic transformation approach in solution was developed. Also, the kinetics of polymorphic transformation was investigated to effectively control polymorphs. The AD crystals were obtained by crystallization at -10°C, and then the polymorphic transformation was induced by raising temperature. The polymorphs of AD were confirmed using DSC, XRD and solubility analyses. The polymorphic fraction during transformation was monitored for kinetic investigation. Via polymorphic transformation in solution, four polymorphs of AD were found and two of them were new (NF-I, NF-II). The DSC analysis revealed that solvate form (NF-I) was changed to form-V in solid state, and then re-crystallized to NF-II at 93°C, and finally became form-I at 97°C. This serial change of polymorphs in DSC was identical to polymorphic transformation sequence in solution. The kinetic rates of polymorphic transformation described by nucleation and mass transfer theories were well matched with experimental measurement. The polymorphic transformation approach was effective to search polymorphs of which the structure was changed to the other one in the solution. The kinetic information of polymorphic transformation predicted by Volmer's nucleation model and Stokes-Einstein diffusion equation was valuable for exact control of polymorphic purity.
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14
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Liu W, Wang WD, Wang W, Bai S, Dybowski C. Influence of Structure on the Spectroscopic Properties of the Polymorphs of Piroxicam. J Phys Chem B 2010; 114:16641-9. [DOI: 10.1021/jp1084444] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Wei Liu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Wei David Wang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Wei Wang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Shi Bai
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Cecil Dybowski
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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15
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Yu L. Polymorphism in molecular solids: an extraordinary system of red, orange, and yellow crystals. Acc Chem Res 2010; 43:1257-66. [PMID: 20560545 DOI: 10.1021/ar100040r] [Citation(s) in RCA: 191] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Diamond and graphite are polymorphs of each other: they have the same composition but different structures and properties. Many other substances exhibit polymorphism: inorganic and organic, natural and manmade. Polymorphs are encountered in studies of crystallization, phase transition, materials synthesis, and biomineralization and in the manufacture of specialty chemicals. Polymorphs can provide valuable insights into crystal packing and structure-property relationships. 5-Methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, known as ROY for its red, orange, and yellow crystals, has seven polymorphs with solved structures, the largest number in the Cambridge Structural Database. First synthesized by medicinal chemists, ROY has attracted attention from solid-state chemists because it demonstrates the remarkable diversity possible in organic solids. Many structures of ROY polymorphs and their thermodynamic properties are known, making ROY an important model system for testing computational models. Though not the most polymorphic substance on record, ROY is extraordinary in that many of its polymorphs can crystallize simultaneously from the same liquid and are kinetically stable under the same conditions. Studies of ROY polymorphs have revealed a new crystallization mechanism that invalidates the common view that nucleation defines the polymorph of crystallization. A slow-nucleating polymorph can still dominate the product if it grows rapidly and nucleates on another polymorph. Studies of ROY have also helped understand a new, surprisingly fast mode of crystal growth in organic liquids cooled to the glass transition temperature. This growth mode exists only for those polymorphs that have more isotropic, and perhaps more liquid-like, packing. The rich polymorphism of ROY results from a combination of favorable thermodynamics and kinetics. Not only must there be many polymorphs of comparable energies or free energies, many polymorphs must be kinetically stable and crystallize at comparable rates to be observed. This system demonstrates the unique insights that polymorphism provides into solid-state structures and properties, as well as the inadequacy of our current understanding of the phenomenon. Despite many studies of ROY, it is still impossible to predict the next molecule that is equally or more polymorphic. ROY is a lucky gift from medicinal chemists.
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Affiliation(s)
- Lian Yu
- School of Pharmacy and Department of Chemistry, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705
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16
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Serezhkin VN, Pushkin DV, Serezhkina LB. Analysis of the conformational polymorph crystal structures by means of molecular Voronoi-Dirichlet polyhedra. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s1063774510040048] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Liu W, Wang WD, Wang W, Bai S, Dybowski C. Measurement of the principal values of the chemical-shift tensors of overlapping protonated and unprotonated carbons with the 2D-SUPER technique and dipolar dephasing (DD-SUPER). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 206:177-181. [PMID: 20667754 DOI: 10.1016/j.jmr.2010.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 06/27/2010] [Accepted: 07/02/2010] [Indexed: 05/29/2023]
Abstract
A modified 2D-SUPER technique is demonstrated to allow independent measurement of the principal values of the chemical-shift tensors of overlapping protonated and unprotonated carbons. The insertion of a dipolar-dephasing period into the sequence causes loss of signal from protonated carbons. The spectrum obtained with this modification allows one to determine the principal values of the unprotonated carbons with high precision. Subsequent fitting of the usual 2D-SUPER spectrum, with the chemical-shift parameters of the unprotonated carbons fixed, gives the parameters of the overlapped resonances of the protonated carbons. As an example, we report the determination of the (13)C chemical-shift parameters of the carbons of form II of piroxicam. The experimental results are compared with those obtained from calculations using the DFT/GIAO method. Potential applications of this method are discussed.
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Affiliation(s)
- Wei Liu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, China
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18
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Quantitation of a polymorphic mixture of an active pharmaceutical ingredient with solid state 13C CPMAS NMR spectroscopy. Int J Pharm 2010; 394:18-25. [DOI: 10.1016/j.ijpharm.2010.04.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 03/05/2010] [Accepted: 04/13/2010] [Indexed: 11/23/2022]
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19
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Clayden J, Fletcher SP, Rowbottom SJM, Helliwell M. Conformational Preferences of a Polar Biaryl: A Phase- and Enantiomeric Purity-Dependent Molecular Hinge. Org Lett 2009; 11:2313-6. [DOI: 10.1021/ol9006635] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan Clayden
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Stephen P. Fletcher
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - S. J. M. Rowbottom
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Madeleine Helliwell
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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Affiliation(s)
- Cecil Dybowski*
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Shi Bai
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
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22
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Mohapatra H, Eckhardt CJ. Elastic Constants and Related Mechanical Properties of the Monoclinic Polymorph of the Carbamazepine Molecular Crystal. J Phys Chem B 2008; 112:2293-8. [DOI: 10.1021/jp077014c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Himansu Mohapatra
- Department of Chemistry, Center for Materials Research and Analysis, University of NebraskaLincoln, Lincoln, Nebraska 68588-0304
| | - Craig J. Eckhardt
- Department of Chemistry, Center for Materials Research and Analysis, University of NebraskaLincoln, Lincoln, Nebraska 68588-0304
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23
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Liberski AR, Tizzard GJ, Diaz-Mochon JJ, Hursthouse MB, Milnes P, Bradley M. Screening for Polymorphs on Polymer Microarrays. ACTA ACUST UNITED AC 2008; 10:24-7. [DOI: 10.1021/cc700107x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Fonseca I, Hayes SE, Blümich B, Bertmer M. Temperature stability and photodimerization kinetics of β-cinnamic acid and comparison to its α-polymorph as studied by solid-state NMR spectroscopy techniques and DFT calculations. Phys Chem Chem Phys 2008; 10:5898-907. [DOI: 10.1039/b806861e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Bashkirava A, Andrews PC, Junk PC, Robertson EG, Spiccia L, Vanderhoek N. Conformational Polymorphism inN-(4′-methoxyphenyl)- 3-bromothiobenzamide. Chem Asian J 2007; 2:530-8. [PMID: 17441191 DOI: 10.1002/asia.200600410] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Three conformational polymorphs of N-(4'-methoxyphenyl)-3-bromothiobenzamide, yellow alpha, orange beta, and yellow gamma, have been identified by single-crystal X-ray diffraction. The properties and structure of the polymorphs were examined with FT Raman, FTIR (ATR), and UV/Vis spectroscopy, as well as differential scanning calorimetry. Computational data on rotational barriers in the isolated gas-phase molecule indicate that the molecular conformation found in the alpha form is energetically preferred, but only by around 2 kJ mol(-1) over the gamma conformation. The planar molecular structure found in the beta form is destabilized by 10-14 kJ mol(-1), depending on the calculation method. However, experimental evidence suggests that the beta polymorph is the most stable crystalline phase at room temperature. This is attributed to the relative planarity of this structure, which allows more and stronger intermolecular interactions, that is, more energetically effective packing. Calculated electronic-absorption maxima were in agreement with experimental spectra.
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Affiliation(s)
- Anastasiya Bashkirava
- School of Chemistry, CRC Smartprint, Monash University, Clayton, Victoria 3800, Australia
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Farrer BT, Peresypkin A, Wenslow RM. Quantitation of Crystalline Material within a Liquid Vehicle using 1H/19F CP/MAS NMR. J Pharm Sci 2007; 96:264-7. [PMID: 17051585 DOI: 10.1002/jps.20759] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A method to detect and quantify a small amount crystalline material within a liquid solution of solubilized material is described. 19F CP-MAS ssNMR was investigated as a technique to detect low levels (0.2 mg/g) of crystalline sodium (2R)-7-{3-[2-chloro-4-(2,2,2-trifluoroethoxy)phenoxy]propoxy}-2-methyl-3,4-dihydro-2H-chromane-2-carboxylate (I) within a solid mixture (with microcrystalline cellulose) and a slurry with a liquid vehicle (capric and caprylic acid triglycerides). The results demonstrate that the area of the 19F CP/MAS signal obtained in 25 min at 25 degrees C is linearly dependent (R2=0.997) on the mass of I within the ssNMR rotor. Slopes of CP-MAS peak area versus mass of I in the rotor were nearly identical for the solid mixture and slurry suspension. Signal-to-noise ratio for the low potency slurry suggest detection and quantitation of 0.1 mg of crystalline I in the rotor, corresponding to 2 mg/g of crystalline material within the slurry suspension.
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Affiliation(s)
- Brian T Farrer
- Merck & Co., Inc., Pharmaceutical R&D, 126 East Lincoln Avenue, Rahway, New Jersey 07065, USA.
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