Naslov
Solid-State Chemistry and Polymorphism of the Nucleobase Adenine

Autori
Stolar, Tomislav ; Lukin, Stipe ; Požar, Josip ; Rubčić, Mirta ; Day, Graeme M. ; Biljan, Ivana ; Šišak Jung, Dubravka ; Horvat, Gordan ; Užarević, Krunoslav ; Meštrović, Ernest ; Halasz, Ivan

Izvornik
Crystal growth & design (1528-7483) 16 (2016), 6; 3262-3270

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
adenine ; polymorphism ; solid-state ; powder diffraction ; thermodynamics

Sažetak
The nucleobase adenine plays a pivotal role in the chemistry of life but is also becoming increasingly interesting as a building block in the synthesis of functional solid materials. Although commercially available as a solid, adenine’s solid-state chemistry has so far been neglected. In this comprehensive study it is shown that adenine is most often marketed as a mixture of two polymorphs, one previously known and a new polymorph. Both polymorphs exhibit layered structures with different hydrogen-bonding patterns within layers. The crystal structure of the new polymorph was elucidated using synchrotron powder X- ray diffraction. Polymorph occurrence conditions, interconversion, and the difference in their thermodynamic stability were established theoretically and experimentally revealing the polymorph with Z' = 2 (known) as stable relative to the polymorph with Z' = 1 (new). The adenine layers in both polymorphs are connected by weak interactions likely resulting in stacking faults which are manifested in anisotropic line broadening of their powder diffraction patterns. Analysis of a few commercial samples of adenine revealed them all to be a polymorph mixture, which could be inconvenient in experiments where properties of the solid material could be relevant.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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