Solid-State Chemistry and Polymorphism of the Nucleobase Adenine
详细信息 查看全文
- 作者：Tomislav Stolar ; Stipe Lukin ; Josip Požar ; Mirta Rubčić ; Graeme M. Day ; Ivana Biljan ; Dubravka Šišak Jung ; Gordan Horvat ; Krunoslav Užarević ; Ernest Meštrović ; Ivan Halasz
- 刊名：Crystal Growth & Design
- 出版年：2016
- 出版时间：June 1, 2016
- 年：2016
- 卷：16
- 期：6
- 页码：3262-3270
- 全文大小：515K
- 年卷期：0
- ISSN：1528-7505
文摘
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.