Sangavi Marimuthu, Mohana Marimuthu, Butcher Ray J, McMillen Colin D
Department of Chemistry Thanthai Periyar Government Arts and Science College Tiruchirappalli-620 023 (Affiliated to Bharathidasan University, Tiruchirappalli 620 024 Tamil Nadu India) Tamil Nadu India.
Department of Chemistry, Periyar Maniammai Institute of Science and Technology (Deemed to be University), Thanjavur 613 403, Tamil Nadu, India.
Acta Crystallogr E Crystallogr Commun. 2025 May 23;81(Pt 6):549-553. doi: 10.1107/S2056989025004463. eCollection 2025 Jun 1.
The 1:1 cocrystal of 5-fluoro-cytosine (5FC) and 4-hy-droxy-benzaldehyde (4HB), CHFNO·CHO has been synthesized and its structure characterized by single-crystal X-ray diffraction and Hirshfeld surface analysis. The compound crystallizes in the monoclinic 2/ space group. A robust supra-molecular architecture is stabilized by N-H⋯O, N-H⋯N, C-H⋯O and C-H⋯F hydrogen bonds, forming (8), (22), (32), and (34) ring motifs. The N-H⋯O and N-H⋯N hydrogen bonds form strong directional inter-actions, contributing to the (8) and (34) motifs through dimeric and extended ring structures. O-H⋯O inter-actions link 5FC and 4HB mol-ecules, generating an (32) ring that enhances the packing. Weaker C-H⋯F bonds help form the (22) tetra-meric motif, supporting the overall three-dimensional supra-molecular framework. Additionally, C-F⋯π inter-actions between the fluorine atom and the aromatic ring add further to the crystal cohesion. Hirshfeld surface analysis and two-dimensional fingerprint plots confirm that O⋯H/H⋯O contacts are the most significant, highlighting the central role of hydrogen bonding in the stability and organization of the crystal structure.
5-氟胞嘧啶（5FC）与4-羟基苯甲醛（4HB）的1:1共晶体CHFNO·CHO已被合成，其结构通过单晶X射线衍射和 Hirshfeld 表面分析进行了表征。该化合物结晶于单斜晶系2/空间群。一种稳健的超分子结构通过N-H⋯O、N-H⋯N、C-H⋯O和C-H⋯F氢键得以稳定，形成了 （8）、 （22）、 （32）和 （34）环基序。N-H⋯O和N-H⋯N氢键形成强定向相互作用，通过二聚体和扩展环结构促成 （8）和 （34）基序。O-H⋯O相互作用连接5FC和4HB分子，生成一个 （32）环，增强了堆积。较弱的C-H⋯F键有助于形成 （22）四聚体基序，支撑整体三维超分子框架。此外，氟原子与芳香环之间的C-F⋯π相互作用进一步增强了晶体凝聚力。Hirshfeld表面分析和二维指纹图谱证实O⋯H/H⋯O接触最为显著，突出了氢键在晶体结构稳定性和组织中的核心作用。
