A new polymorph of 2,6-diaminopyridine

Hall, Victoria M.; Bertke, Jeffery A.; Swift, Jennifer A.

doi:10.1107/s2053229617014978

Cited by 4 publications

(2 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The DAP groups can build intermolecular hydrogen bridges while the pyridine ring moeity can promote – -stacking 27 , 28 . The 2,6 diamino pyridine itself is known to crystallize in the form of different polymorphs 29 . The ring N-atom together with the O-atoms may act as acceptor sites while the amino H-atoms act as donors.…”

Section: Resultsmentioning

confidence: 99%

Tuning layered superstructures in precision polymers

Danke

Reimann

Binder

et al. 2020

Sci Rep

View full text Add to dashboard Cite

An approach to influence and control layered superstructures by varying the methylene sequence length between two consecutive functional groups in linear precision polymers containing 2,6-diaminopyridine (DAP) groups is presented. Layered superstructures with repeating units involving three monomeric units along the chain direction with very high coherence lengths upto 110 nm are observed in case of shorter alkyl segments, (16 and 18 CH 2 units), while more conventional layer superstructures incorporating only one monomer are found for related polymers with 20 CH 2 units per methylene sequence. A building block model explaining the unusually large periodicity of three monomeric units is proposed wherein layers containing crystalline or amorphous methylene sequences occur in different combinations. Occurrence of different layered structures depending on crystallization conditions, methylene sequence length as well as functional group type is explained by a competition of H-interactions between the DAP groups and the van der Waal forces between the hydrophobic methylene groups.

show abstract

Section: Resultsmentioning

confidence: 99%

Tuning layered superstructures in precision polymers

Danke

Reimann

Binder

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The 1:1 mixtures of uric acid and ( 1 ), ( 2 ), and ( 6 ) had diffraction lines corresponding to UA ; the 1:1 mixture with ( 10 ) yielded uric acid dihydrate. Some samples had additional diffraction lines corresponding to the additive , and may contain small amounts of other phases that we did not attempt to further characterize.…”

Section: Resultsmentioning

confidence: 99%

Uric Acid Crystallization Interrupted with Competing Binding Agents

Hall

Thornton

Miehls

et al. 2019

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

Uric acid crystallization in humans is associated with undesirable medical conditions including the formation of gout deposits and kidney stones. A major contributing factor to uric acid biomineralization, most often as either monosodium urate (MSU) or anhydrous uric acid (UA), is its relatively low solubility in physiologic solutions. Using bidentate and tridentate binding patterns designed to disrupt the binding motifs observed in the major physiologic forms, several heterocycles were identified which (1) significantly delay the time required for visible uric acid crystals to appear and/or (2) yield new 1:1 uric acid cocrystal phases. All five of the new phases obtained exhibited a multidentate hydrogen bonding motif between components. Fluorescence assays showed that three of the cocrystals were 3–6× more soluble than the natural forms. The same competitive-binding approach was then extended to trimethoprim, an FDA-approved drug with the same substructure as the most effective binding agents. Addition of trimethoprim to uric acid solutions significantly delayed the crystallization times and also yielded a new cocrystal form with a solubility greater than MSU. These results serve to illustrate the potential benefits of repurposing existing pharmaceuticals to treat uric acid diseases.

show abstract