Skip to content
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Publication Details
AFRICAN RESEARCH NEXUS
SHINING A SPOTLIGHT ON AFRICAN RESEARCH
chemistry
Polymorphic co-crystals from polymorphic co-crystal formers: Competition between carboxylic acid⋯pyridine and phenol⋯pyridine hydrogen bonds
Crystal Growth and Design, Volume 13, No. 9, Year 2013
Notification
URL copied to clipboard!
Description
The recent literature has shown an increase in the number of co-crystals reported to be polymorphic, with at least 45 such systems identified thus far. The question of whether co-crystals, defined as any multicomponent neutral molecular complex that forms a crystalline solid, are inherently less prone to polymorphism than the individual components is shown to be untrue in four sets of polymorphic co-crystals. The co-crystal formers in this study, acridine, nicotinamide, 3-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, malonic acid, and pimelic acid, are all polymorphic in their unimolecular states and are shown to be dimorphic in the following combinations: (3-hydroxybenzoic acid)·(acridine) [1(I) and 1(II)], (2,4-dihydroxybenzoic acid)·(nicotinamide) [4(I) and 4(II)], (malonic acid) ·(nicotinamide) [5(I) and 5(II)], and (pimelic acid) ·(nicotinamide) [6(I) and 6(II)]. These co-crystals are assembled primarily using carboxylic acid and phenol hydrogen bond donors that hydrogen bond to pyridine N or amide carbonyl acceptors. Two different combinations of donors and acceptors are primarily responsible for the formation of polymorphs in 1 and 4, whereas conformational differences within the malonic and pimelic acid molecules lead to different packing arrangements using the same combination of hydrogen bonded interactions in 5 and 6. The 1:2 co-crystal of (3-hydroxybenzoic acid)·(acridine)2 (2) displays both the phenol O-H⋯N hydrogen bond observed in 1(I) and the carboxylic acid O-H⋯N hydrogen bond observed in 1(II). In addition, a methanol solvate of (2,4-dihydroxybenzoic acid)·(nicotinamide) (3) is reported. DFT calculations show that the carboxylic acid⋯pyridine hydrogen bond is strongest and one of co-crystallization's most useful interactions. © 2013 American Chemical Society.
Authors & Co-Authors
Lemmerer, Andreas
South Africa, Johannesburg
University of the Witwatersrand
Adsmond, Daniel A.
United States, Big Rapids
Ferris State University
Esterhuysen, Catharine
South Africa, Stellenbosch
Stellenbosch University
Bernstein, Joel
United Arab Emirates, Abu Dhabi
Nyu Abu Dhabi
Israel, Beer-sheva
Ben-gurion University of the Negev
Statistics
Citations: 76
Authors: 4
Affiliations: 5
Identifiers
Doi:
10.1021/cg4006357
ISSN:
15287483
e-ISSN:
15287505