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Lu T, Lei J, Gou Q, Feng G. Weak hydrogen bonds between alkyl halides and amides: The microwave spectroscopic and theoretical study of the difluoromethane⋯formamide complex. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 241:118681. [PMID: 32653826 DOI: 10.1016/j.saa.2020.118681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/23/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
The pure rotational spectrum of the complex of difluoromethane with formamide was investigated by means of microwave spectroscopy supplemented with theoretical calculations. The hyperfine structure arising from the 14N nuclear quadrupole coupling effect was completely resolved. The most stable isomer that displays the Cs symmetry with the ∠HCH angle of difluoromethane being bisected by the ab-plane of formamide was detected. The two moieties in the detected isomer are connected via one N-H⋯F and one bifurcated CH2⋯O weak hydrogen bonds confirmed by the non-covalent interaction plot and natural bond orbital analyses. The distances of the NH⋯F and CH2⋯O interactions were determined to be 2.140(14) Å and 2.749(14) Å, respectively. The NH⋯F bond angle was determined to be 150.7°. Symmetry-adapted perturbation theory analysis indicates that the electrostatic component is the largest contributor to the total attractive interaction energy of the difluoromethane⋯formamide complex.
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Affiliation(s)
- Tao Lu
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Juncheng Lei
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Qian Gou
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Gang Feng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China.
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Aldiyarov A, Sokolov DY, Nurmukan AY, Ramos MA. Refractive Index at Low Temperature of Tetrachloromethane and Tetrafluoroethane Cryovacuum Condensates. ACS OMEGA 2020; 5:11671-11676. [PMID: 32478257 PMCID: PMC7254780 DOI: 10.1021/acsomega.0c00969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
We present low-temperature measurements of the refractive index of cryofilms of tetrachloromethane and 1,1,1,2-tetrafluoroethane at different condensation and measurement temperatures between 16 and 130 K. Using cryovacuum condensation, we have been able to obtain thin films in an amorphous state for both substances despite them being very bad glass formers. Then, we have studied the evolution of the refractive index with an increasing temperature, including by transitions to ordered or partially disordered crystalline states.
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Affiliation(s)
- Abdurakhman
U. Aldiyarov
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Dmitriy Yurievich Sokolov
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Assel Yerzhumayevna Nurmukan
- Al-Farabi
Kazakh National University Institute of Experimental and Theoretical
Physics, Physico-Technical
Faculty, al-Farabi Ave
71, Almaty 050040, Kazakhstan
| | - Miguel Angel Ramos
- Fisica
de la Materia Condensada, Francisco Tomas y Valiente, Universidad Autonoma de Madrid, 7 Facultad de Ciencias Modulo 03, Madrid E-28049, Spain
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The achiral β-alanine self organizes into supramolecular helical chains in crystallized achiral β-alaninium inorganic/organic acid compounds. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.126920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Jin Y, Wang J, Gou Q, Xia Z, Feng G. Shape and non-bonding interactions in the formic acid-difluoromethane complex by rotational spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 206:185-189. [PMID: 30099317 DOI: 10.1016/j.saa.2018.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/30/2018] [Accepted: 08/04/2018] [Indexed: 06/08/2023]
Abstract
The rotational spectrum of the formic acid-difluoromethane complex was measured by using supersonic-jet Fourier transform microwave spectrometer. Experimental results and ab initio calculations support a conformation formed through a relative strong OH⋯F and a bifurcated weak CH2⋯O hydrogen bonds. The distances of the non-bonding interactions were determined to be 1.960(2) Å and 2.797(3) Å for OH⋯F and CH2⋯O, respectively. The dissociation energy of the complex is estimated to be about 1346 cm-1. The bonding nature of the intermolecular interactions was revealed by non-covalent interaction analysis and electron density difference analysis.
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Affiliation(s)
- Yan Jin
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Juan Wang
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Qian Gou
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China; Collaborative Innovation Center for Brain Science, Chongqing University, No.174 Shazhengjie, Shapingba, Chongqing 400044, China
| | - Zhining Xia
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China.
| | - Gang Feng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China; Collaborative Innovation Center for Brain Science, Chongqing University, No.174 Shazhengjie, Shapingba, Chongqing 400044, China.
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Lu T, Chen J, Zhang J, Gou Q, Xia Z, Feng G. Structure, Conformational Equilibria, and Weak Hydrogen Bonding in the CH 2 F 2 -CF 3 CH 2 F Dimer. Chemphyschem 2018; 19:2655-2661. [PMID: 30133804 DOI: 10.1002/cphc.201800636] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Indexed: 11/09/2022]
Abstract
To probe the multiple configurations of a weakly bound intermolecular complex, the difluoromethane and 1,1,1,2-tetrafluoroethane dimer was investigated by using pulsed jet Fourier transform microwave spectroscopy coupled with quantum chemical calculations. Three isomers were detected in the supersonic jet. Spectroscopic assignments, ab initio calculations and quantum theory of atoms in molecules (QTAIM) analyses prove that all the observed isomers are stabilized through a net of three weak C-H⋅⋅⋅F-C interactions. The interaction energies are estimated to be within 12-13 kJ mol-1 , dominated by electrostatic and dispersion according to Symmetry-Adapted Perturbation Theory (SAPT) analysis. The spectroscopic measurements were also extended to three and two 13 C isotopologues in natural abundance for the isomers II and III, respectively, which lead to precisely structural determinations of these two isomers. The comparison of the relative intensity of these isomers measured in the carrier gases of argon and helium evidenced that isomer II is the global minimum, while the intensities measured in helium suggested that the population of the three isomers in the jet to be NI /NII /NIII ≈1/11/4.
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Affiliation(s)
- Tao Lu
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China
| | - Junhua Chen
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China
| | - Jiaqi Zhang
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China
| | - Qian Gou
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.,Collaborative Innovation Center for Brain Science, Chongqing University, No. 174 Shazhengjie, Shapingba, 400044, Chongqing, China)
| | - Zhining Xia
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China
| | - Gang Feng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.,Collaborative Innovation Center for Brain Science, Chongqing University, No. 174 Shazhengjie, Shapingba, 400044, Chongqing, China)
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Jin Y, Wang J, Gou Q, Xia Z, Feng G. Fluorination effect on conformational preferences of trifluorothioanisole. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.11.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Li X, Zheng Y, Gou Q, Feng G, Xia Z. Microwave spectroscopy of 2-(trifluoromethyl)pyridine⋯water complex: Molecular structure and hydrogen bond. J Chem Phys 2018; 148:044306. [PMID: 29390811 DOI: 10.1063/1.5018164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In order to explore the -CF3 substitution effect on the complexation of pyridine, we investigated the 2-(trifluoromethyl)pyridine⋯water complex by using pulsed jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. Experimental assignment and ab initio calculations confirmed that the observed complex is stabilized through N⋯H-O and O⋯H-C hydrogen bonds forming a five-membered ring structure. The bonding distance in N⋯H-O is determined to be 2.027(2) Å, whilst that in O⋯H-C interaction is 2.728(2) Å. The quantum theory of atoms in molecules analysis indicates that the interaction energy of N⋯H-O hydrogen bond is ∼22 kJ mol-1 and that for O⋯H-C hydrogen bond is ∼5 kJ mol-1. The water molecule lies almost in the plane of the aromatic ring in the complex. The -CF3 substitution to pyridine quenches the tunneling splitting path of the internal motion of water molecule.
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Affiliation(s)
- Xiaolong Li
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Yang Zheng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Qian Gou
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Gang Feng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
| | - Zhining Xia
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China
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