Rotational Spectroscopy Meets Quantum Chemistry for Analyzing Substituent Effects on Non-Covalent Interactions: The Case of the Trifluoroacetophenone-Water Complex
Juncheng Lei,
Silvia Alessandrini,
Junhua Chen,
Yang Zheng,
Lorenzo Spada,
Qian Gou,
Cristina Puzzarini,
Vincenzo Barone
Affiliations
Juncheng Lei
Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, Chongqing 401331, China
Silvia Alessandrini
Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
Junhua Chen
Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, Chongqing 401331, China
Yang Zheng
Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, Chongqing 401331, China
Lorenzo Spada
Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
Qian Gou
Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, Chongqing 401331, China
Cristina Puzzarini
Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via Selmi 2, 40126 Bologna, Italy
Vincenzo Barone
Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,2,2-trifluoroacetophenone. Accurate intermolecular parameters featuring one classical O-H···O hydrogen bond and one weak C-H···O hydrogen bond have been determined by means of a semi-experimental approach for equilibrium structure. Furthermore, insights on the nature of the established non-covalent interactions have been unveiled by means of different bond analyses. The comparison with the analogous complex formed by acetophenone with water points out the remarkable role played by fluorine atoms in tuning non-covalent interactions.
