Order and Disorder in the Structures of Two Crystal Polymorphs of the Adduct Bis(Quinolinium-2-Carboxylate) DL-Malic Acid
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Author(s)
Smith, Graham
Wermuth, Urs D
Griffith University Author(s)
Year published
2011
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The structures of two polymorphs of the anhydrous cocrystal adduct of bis(quinolinium-2-carboxylate) DL-malic acid, one triclinic the other monoclinic and disordered, have been determined at 200 K. Crystals of the triclinic polymorph 1 have space group P-1, with Z = 1 in a cell with dimensions a = 4.4854(4), b = 9.8914(7), c = 12.4670(8) Ŭ a = 79.671(5), ߠ= 83.094(6), ? = 88.745(6)Crystals of the monoclinic polymorph 2 have space group P21/c, with Z = 2 in a cell with dimensions a = 13.3640(4), b = 4.4237(12), c = 18.4182(5) Ŭ ߠ= 100.782(3)Both structures comprise centrosymmetric cyclic hydrogen-bonded quinolinic acid ...
View more >The structures of two polymorphs of the anhydrous cocrystal adduct of bis(quinolinium-2-carboxylate) DL-malic acid, one triclinic the other monoclinic and disordered, have been determined at 200 K. Crystals of the triclinic polymorph 1 have space group P-1, with Z = 1 in a cell with dimensions a = 4.4854(4), b = 9.8914(7), c = 12.4670(8) Ŭ a = 79.671(5), ߠ= 83.094(6), ? = 88.745(6)Crystals of the monoclinic polymorph 2 have space group P21/c, with Z = 2 in a cell with dimensions a = 13.3640(4), b = 4.4237(12), c = 18.4182(5) Ŭ ߠ= 100.782(3)Both structures comprise centrosymmetric cyclic hydrogen-bonded quinolinic acid zwitterion dimers [graph set R22(10)] and 50% disordered malic acid molecules which lie across crystallographic inversion centres. However, the oxygen atoms of the malic acid carboxylic groups in 2 are 50% rotationally disordered whereas in 1 these are ordered. There are similar primary malic acid carboxyl O-H緷Oquinaldic acid hydrogen-bonding chain interactions in each polymorph, extended into two-dimensional structures but in 1 this involves centrosymmetric cyclic head-to-head malic acid hydroxyl-carboxyl O-H緷O interactions [graph set R22(10)] whereas in 2 the links are through single hydroxy-carboxyl hydrogen bonds. Graphical Abstract The structure determinations of two crystal polymorphs of the 2:1 adduct of quinolinium-2-carboxylate with DL-malic acid has shown one to be triclinic and ordered while in the second monoclinic form the carboxylic acid groups of the malic acid moiety are disordered.
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View more >The structures of two polymorphs of the anhydrous cocrystal adduct of bis(quinolinium-2-carboxylate) DL-malic acid, one triclinic the other monoclinic and disordered, have been determined at 200 K. Crystals of the triclinic polymorph 1 have space group P-1, with Z = 1 in a cell with dimensions a = 4.4854(4), b = 9.8914(7), c = 12.4670(8) Ŭ a = 79.671(5), ߠ= 83.094(6), ? = 88.745(6)Crystals of the monoclinic polymorph 2 have space group P21/c, with Z = 2 in a cell with dimensions a = 13.3640(4), b = 4.4237(12), c = 18.4182(5) Ŭ ߠ= 100.782(3)Both structures comprise centrosymmetric cyclic hydrogen-bonded quinolinic acid zwitterion dimers [graph set R22(10)] and 50% disordered malic acid molecules which lie across crystallographic inversion centres. However, the oxygen atoms of the malic acid carboxylic groups in 2 are 50% rotationally disordered whereas in 1 these are ordered. There are similar primary malic acid carboxyl O-H緷Oquinaldic acid hydrogen-bonding chain interactions in each polymorph, extended into two-dimensional structures but in 1 this involves centrosymmetric cyclic head-to-head malic acid hydroxyl-carboxyl O-H緷O interactions [graph set R22(10)] whereas in 2 the links are through single hydroxy-carboxyl hydrogen bonds. Graphical Abstract The structure determinations of two crystal polymorphs of the 2:1 adduct of quinolinium-2-carboxylate with DL-malic acid has shown one to be triclinic and ordered while in the second monoclinic form the carboxylic acid groups of the malic acid moiety are disordered.
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Journal Title
Journal of Chemical Crystallography
Volume
41
Issue
2
Copyright Statement
© 2010 Springer Netherlands. This is an electronic version of an article published in Journal of Chemical Crystallography, Volume 41, Number 2 (2011), 241-246. Journal of Chemical Crystallography is available online at: http://www.springerlink.com/ with the open URL of your article.
Subject
Physical chemistry