Exploring C-F···π Interactions: Synthesis, Characterization, and Surface Analysis of Copper β-Diketone Complexes

ACS Omega. 2024 Jan 24;9(5):5563-5575. doi: 10.1021/acsomega.3c07639. eCollection 2024 Feb 6.

Abstract

Synthesis and characterization of two novel copper β-diketone complexes, where halogen bonds play a pivotal role in shaping their multifaceted structural landscape, have been done in the present study. This study employs X-ray diffraction, ultraviolet-visible (UV-vis) spectroscopy, and infrared (IR) spectroscopy to investigate two copper β-diketone complexes, [Cu(L1)2(ttfa)2]·2CH3OH (1) and [Cu(L1)(dfpb)2] (2), where Httfa is 4,4,4-trifluoro-1-(thiophen-2-yl)butan-3,1-dione and Hdfpb is 4,4-difluoro-1-phenylbutane-1,3-dione. Complex 1 displays a halogen bond, which contributes to its uniqueness. The coordination sphere around the copper atoms was found to be octahedral for complex 1 and pyramid with a square base for complex 2. The study also extensively discusses the interactions present in these complexes. Hirshfeld surface analysis was employed to gain a more detailed understanding of these interactions, and the results showed that hydrogen-bond interactions contributed above 30% of the whole surface area in both complexes. Additionally, the halogen bond in complex 1 was found to contribute approximately 8% of the surface. Overall, this study provides valuable insights into the structural properties and interactions of copper β-diketone complexes, which could have potential applications in various fields.