Abstract
Purpose
The solid-state luminescence spectroscopy of organic molecules is strongly affected by the effects of excited state energy transfer, with the fluorescence of solids often differing significantly from the fluorescence of the molecule dissolved in a solution phase. Because the magnitude of these solid-state effects is determined by the crystallography of the system, solid-state fluorescence studies can be used to gain insight into the polymorphism of the system. To this end, the spectroscopic properties of four polymorphs of diflunisal have been obtained, and compared to the properties of the molecule in the solution phase.
Methods
Fluorescence excitation and emission spectra were obtained on four polymorphic forms of diflunisal, and on the compound dissolved in water.
Results
It was found that exciton effects dominate the excitation spectra of diflunisal in the four studied polymorphic forms. These phenomena lead to a decrease in the energy of the excitation bands relative to that observed for the free molecule in fluid solution, and in a splitting of the excitation peak into two Davydov components.
Conclusions
The trends in the excitation and emission spectra led to the grouping of diflunisal Forms I, II, and III into one category, and diflunisal Form IV into a separate category. Because other work has established that Form IV is characterized by the highest crystal density and consequent degree of intermolecular interaction, the magnitude of the exciton coupling can be used to estimate the degree of face-to-face overlap of the salicylate-type fluorophores.
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References
T. L. Threlfall (1995) ArticleTitleAnalysis of organic polymorphs—a review Analyst 120 2435–2460 Occurrence Handle1:CAS:528:DyaK2MXovFOit78%3D
H. G. Brittain (1997) ArticleTitleSpectral methods for the characterization of polymorphs and solvates J. Pharm. Sci. 86 405–412 Occurrence Handle1:CAS:528:DyaK2sXhslamt7g%3D Occurrence Handle9109040
H. G. Brittain (1999) Methods for the characterization of polymorphs and solvates H.G. Brittain (Eds) Polymorphism in Pharmaceutical Solids Marcel Dekker New York 227–278
J. Bernstein (2002) Analytical techniques for studying and characterizing polymorphs. Polymorphism in Molecular Crystals Clarendon Press London 94–150
D. E. Bugay A. C. Williams (1995) Vibrational spectroscopy H. G. Brittain (Eds) Physical Characterization of Pharmaceutical Solids Marcel Dekker New York 59–91
W. P. Findlay D. E. Bugay (1998) ArticleTitleUtilization of fourier transform raman spectroscopy for the study of pharmaceutical crystal forms J. Pharm. Biomed. Anal. 16 921–930 Occurrence Handle1:CAS:528:DyaK1cXitFCjtrs%3D Occurrence Handle9547695
C. J. Frank (1999) Review of pharmaceutical applications of raman spectroscopy M. J. Pelletier (Eds) Analytical Applications of Raman Spectroscopy Blackwell Science London 224–275
D. E. Bugay (1993) ArticleTitleSolid-state nuclear magnetic resonance spectroscopy: theory and pharmaceutical applications Pharm. Res. 10 317–327 Occurrence Handle1:CAS:528:DyaK3sXitF2mt7g%3D Occurrence Handle8464803
D. E. Bugay (1995) Magnetic resonance spectrometry H. G. Brittain (Eds) Physical Characterization of Pharmaceutical Solids Marcel Dekker New York 93–125
P. A. Tishmack D. E. Bugay S. R. Byrn (2003) ArticleTitleSolid-state nuclear magnetic resonance spectroscopy—pharmaceutical applications J. Pharm. Sci. 92 441–474 Occurrence Handle1:CAS:528:DC%2BD3sXitVWquro%3D Occurrence Handle12587108
M. Tanaka H. Matsui J.-I. Mizoguchi S. Kashino (1994) ArticleTitleOptical properties, thermochromism, and crystal structures of the dimorphs of 2-iodoanilinium picrate Bull. Chem. Soc. Jpn. 67 1572–1579 Occurrence Handle1:CAS:528:DyaK2cXlvFWqtrc%3D
Y. Inouye Y. Sakaino (2000) ArticleTitleRed, orange, and yellow crystals of 4,5-bis(4-methoxy phenyl)-2-(3-nitrophenyl)-1H-imidazole Acta Crystallogr. C56 884–887 Occurrence Handle1:CAS:528:DC%2BD3cXltlyku74%3D
X. He U. J. Griesser J. G. Stowell T. B. Borchardt S. R. Byrn (2001) ArticleTitleConformational color polymorphism and control of crystallization of 5-methyl-2-nitrophenyl)amino]-3-thiophenecarbonitrile J. Pharm. Sci. 90 374–388
J. R. Lakowicz (1999) Principles of Fluorescence Spectroscopy EditionNumber2 Kluwer/Plenum New York
H. G. Brittain (2004) ArticleTitleFluorescence studies of the transformation of carbamazepine anhydrate form-III to its dihydrate phase J.Pharm. Sci. 93 375–383 Occurrence Handle1:CAS:528:DC%2BD2cXhsFansr4%3D Occurrence Handle14705194
M. L. Cotton R. A. Hux (1985) Diflunisal K. Florey (Eds) Analytical Profiles of Drug Substances Academic Press Orlando 491–526
M. C. Martinez-Oharriz C. Martin M. M. Goni C. Rodriguez-Espinosa M. C. Tros de Ilarduya-Apaolaza M. Sanchez (1994) ArticleTitlePolymorphism of diflunisal: isolation and solid-state characteristics of a new crystal form J. Pharm. Sci. 83 174–177 Occurrence Handle1:CAS:528:DyaK2cXmt1WjsA%3D%3D Occurrence Handle8169784
L. K. Hansen G. L. Perlovich A. Bauer-Brandl (2001) ArticleTitleThe 1:1 hydrate of diflunisal Acta Cryst. E57 o477–o479 Occurrence Handle1:CAS:528:DC%2BD3MXjtFeit7Y%3D
L. K. Hansen G. L. Perlovich A. Bauer-Brandl (2001) ArticleTitleDiflunisal-hexane (4/1) Acta Cryst. E57 o604–o606 Occurrence Handle1:CAS:528:DC%2BD3MXkslKgtro%3D
A. Bauer-Brandl G. L. Perlovich L. K. Hansen (2001) ArticleTitleInterrelation between thermochemical and structural data of polymorphs exemplified by diflunisal J. Pharm. Sci. 91 1036–1045
W. I. Cross N. Blagden R. J. Davey R. G. Pritchard M. A. Neumann R. J. Roberts R. C. Rowe (2003) ArticleTitleA whole output strategy for polymorph screening: combining crystal structure prediction, graph set analysis, and targeted crystallization experiments in the case of diflunisal Cryst. Growth Des. 3 151–158 Occurrence Handle1:CAS:528:DC%2BD38XpsFCnsr0%3D
C. A. Parker (1968) NoChapterTitle Photoluminescence of Solutions Elsevier Amsterdam 186–191
J. I. Frenkel (2003) ArticleTitleOn the transformation of light into heat in solids Phys. Rev. 37 151–158
A. S. Davydov (1962) Theory of Molecular Excitons McGraw-Hill New York
D. P. Craig S. H. Walmsley (1968) Excitons in Molecular Crystals W.A. Benjamin New York
D. P. Craig and P. C. Hobbins. The polarized spectrum of anthracene. Part I, the assignment of the intense short wavelength system. J. Chem. Soc. London 539–548 (1955).
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This paper is to be considered as Part 2 in the series, “Studies of the Fluorescence of Pharmaceutical Materials in the Solid State,” with reference (17) being the preceding paper in the series.
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Brittain, H.G., Elder, B.J., Isbester, P.K. et al. Solid-State Fluorescence Studies of Some Polymorphs of Diflunisal*. Pharm Res 22, 999–1006 (2005). https://doi.org/10.1007/s11095-005-4595-y
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DOI: https://doi.org/10.1007/s11095-005-4595-y