Occurrences of bimolecular C-H···O synthons in organic crystal structures in the Cambridge Database
- 作者：Nangia ; Ashwini
- 关键词：Supramolecular synthon ; C-H· ; · ; · ; O hydrogen bond ; Cambridge Structural Database ; Multipoint recognition
- 刊名：Crystal Engineering
- 出版年：2001
- 期刊代码：26_14630184
- 类别：ms
- 出版时间：March, 2001
- 卷：4
- 期：1
- 页码：49-59
- 文件大小：229 K
摘要
The control of molecular aggregation in the solid state is a current challenge in crystal engineering and materials chemistry. Supramolecular retrosynthesis via recurring synthons is an attractive strategy for the design and self-assembly of target crystal structures. This database study deals with occurrences of two- and three-point intermolecular C-H···O hydrogen bonded synthons in fragments of DAD, DDA and DDD type in organic crystals, where D=C(sp2)-H and A=O-atom. The number of hits with fragments DAD>DDA>>DDD (2606, 1485, 461 hits). Two-point recognition synthon DA
AD occurs more frequently in DAD and DDA structures (225, 111 hits) than DDAA motif in DDA and DDD structures (34, 5 hits). Three-point recognition synthons DADADA, DDAAAD and DDDAAA are extremely rare (3, 0, 1 hits). These frequency data are rationalised in terms of the molecular complexity of fragments, the overriding preference for centrosymmetric packing, and the stringent requirements of donor-acceptor and solubility match in binary crystals.
AD occurs more frequently in DAD and DDA structures (225, 111 hits) than DDAA motif in DDA and DDD structures (34, 5 hits). Three-point recognition synthons DADADA, DDAAAD and DDDAAA are extremely rare (3, 0, 1 hits). These frequency data are rationalised in terms of the molecular complexity of fragments, the overriding preference for centrosymmetric packing, and the stringent requirements of donor-acceptor and solubility match in binary crystals.