Solvates of Sildenafil Saccharinate. A New Host Material
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- 作者：Rahul Banerjee ; Prashant M. Bhatt ; and Gautam R. Desiraju
- 刊名：Crystal Growth & Design
- 出版年：2006
- 出版时间：June 2006
- 年：2006
- 卷：6
- 期：6
- 页码：1468 - 1478
- 全文大小：676K
- 年卷期：v.6,no.6(June 2006)
- ISSN：1528-7505
文摘
Sildenafil saccharinate (SS) forms solvates with a large number of solvents, which are included in distorted hexagonalcavities constituted with N(+)-H···N(-) and C-H···O interactions. All these solvates, except the methanolate, are isostructural andcontain various host-guest O-H···O and C-H···O interactions and also an intramolecular N-H···O hydrogen bond in the sildenafilentity. The C-H···O bonds, in particular, are strong and numerous and play an important role in stabilizing the crystal packing atseveral levels. The solute-solvent ratio varies among the isostructural solvates because of differences in guest size. Solvents withsmaller volume occupy the peripheries of the cavity, while larger solvents are located within the cavity. All the solvates are convertedeasily to the apohost upon heating, and this transformation is associated with a rearrangement of several C-H···O interactions inthe structure. The apohost could also be prepared by grinding the two components, and this procedure led to mixtures of crystallineand amorphous forms. When this ground sample was heated at 120 
C, it was converted into the crystalline SS apohost. In thisfamily of host-guest compounds the host framework is largely invariant and robust, and the guest molecules only play a bystanderrole in the packing. The totally different crystal structure of the methanol solvate argues in favor of using the term pseudopolymorphto describe modulations in the structural landscape of a host-guest system.
C, it was converted into the crystalline SS apohost. In thisfamily of host-guest compounds the host framework is largely invariant and robust, and the guest molecules only play a bystanderrole in the packing. The totally different crystal structure of the methanol solvate argues in favor of using the term pseudopolymorphto describe modulations in the structural landscape of a host-guest system.