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Burton MA, Cheng Q, Halfen DT, Lane JH, DeYonker NJ, Ziurys LM. The structure of ScC 2 (X̃ 2A 1): A combined Fourier transform microwave/millimeter-wave spectroscopic and computational study. J Chem Phys 2020; 153:034304. [PMID: 32716169 DOI: 10.1063/5.0008746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Pure rotational spectra of Sc13C2 (X̃2A1) and Sc12C13C (X̃2A') have been measured using Fourier transform microwave/millimeter-wave methods. These molecules were synthesized in a DC discharge from the reaction of scandium vapor, produced via laser ablation, with 13CH4 or 13CH4/12CH4, diluted in argon. The NKa,Kc = 10,1 → 00,0, 20,2 → 10,1, 30,3 → 20,2, and 40,4 → 30,3 transitions in the frequency range of 14 GHz-61 GHz were observed for both species, each exhibiting hyperfine splittings due to the nuclear spins of 13C (I = 1/2) and/or Sc (I = 7/2). These data have been analyzed with an asymmetric top Hamiltonian, and rotational, spin-rotation, and hyperfine parameters have been determined for Sc13C2 and Sc12C13C. In addition, a quartic force field was calculated for ScC2 and its isotopologues using a highly accurate coupled cluster-based composite method, incorporating complete basis set extrapolation, scalar relativistic corrections, outer core and inner core electron correlation, and higher-order valence correlation effects. The agreement between experimental and computed rotational constants, including the effective constant (B + C), is ∼0.5% for all three isotopologues. This remarkable agreement suggests promise in predicting rotational spectra of new transition metal-carbon bearing molecules. In combination with previous work on Sc12C2, an accurate structure for ScC2 has been established using combined experimental (B, C) and theoretical (A) rotational constants. The radical is cyclic (or T-shaped) with r(Sc-C) = 2.048(2) Å, r(C-C) = 1.272(2) Å, and ∠(C-Sc-C) = 36.2(1)°. The experimental and theoretical results also suggest that ScC2 contains a C2 - moiety and is largely ionic.
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Affiliation(s)
- M A Burton
- Department of Chemistry and Biochemistry, Department of Astronomy, Steward Observatory, University of Arizona, 1305 E. 4th Street, Tucson, Arizona 85719, USA
| | - Q Cheng
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, USA
| | - D T Halfen
- Department of Chemistry and Biochemistry, Department of Astronomy, Steward Observatory, University of Arizona, 1305 E. 4th Street, Tucson, Arizona 85719, USA
| | - J H Lane
- Department of Chemistry and Biochemistry, Department of Astronomy, Steward Observatory, University of Arizona, 1305 E. 4th Street, Tucson, Arizona 85719, USA
| | - N J DeYonker
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, USA
| | - L M Ziurys
- Department of Chemistry and Biochemistry, Department of Astronomy, Steward Observatory, University of Arizona, 1305 E. 4th Street, Tucson, Arizona 85719, USA
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Xu Q, Wang M, Li G, Zhao Y, Yang C. Anharmonic force fields and spectroscopic constants of H2AsO: An ab initio study. MAIN GROUP CHEMISTRY 2019. [DOI: 10.3233/mgc-180714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Qiushuang Xu
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai, China
| | - Meishan Wang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai, China
| | - Gaoshang Li
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai, China
| | - Yanliang Zhao
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai, China
| | - Chuanlu Yang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai, China
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Zhao Y, Wang M, Yang C, Ma X, Li J. DFT calculations for anharmonic force field and spectroscopic constants of YC 2 and its 13C isotopologues. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 191:382-388. [PMID: 29055756 DOI: 10.1016/j.saa.2017.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 06/07/2023]
Abstract
The construction of the complete third and the semi-diagonal quartic force fields including the anharmonicity of the ground state (X˜2A1) for yttrium dicarbide (YC2) is carried out employing the vibrational second-order perturbation theory (VPT2) in combination with the density functional theory (DFT). The equilibrium geometries optimization, anharmonic force field and vibrational spectroscopic constants of YC2 are calculated by B3LYP, B3PW91 and B3P86 methods. Aug-cc-pVnZ (n=D, T, Q) and cc-pVnZ-PP (n=D, T, Q) basis sets are chosen for C and Y atoms, respectively. The calculated geometry parameters of YC2 agree well with the corresponding experimental and previous theoretical results. The bonding characters of YC2 or CC are discussed. Based on the optimized equilibrium geometries, the spectroscopic constants and anharmonic force field of YC2 are calculated. Comparing with the spectroscopic constants of YC2 derived from the experiment, the calculated results show that the B3PW91 and B3P86 methods are superior to B3LYP for YC2. The Coriolis coupling constants, cubic and quartic force constants of YC2 are reasonably predicted. Besides, the spectroscopic constants and anharmonic force field of Y13C2 (X˜2A1) and Y13CC (X˜2A') are calculated for the first time, which are expected to guide the high resolution experimental work for YC2 and its 13C isotopologues.
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Affiliation(s)
- Yanliang Zhao
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China
| | - Meishan Wang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Chuanlu Yang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China
| | - Xiaoguang Ma
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China
| | - Jing Li
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China
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Parida SK, Sahu S, Sharma S. Regioselectivity of third-row maingroup dicarbides, C2X (X = K-Br) for CO interaction: Fukui function and topological analyses. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.06.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Zeng T, Wang H, Lu Y, Xie Y, Wang H, Schaefer HF, Ananth N, Hoffmann R. Tuning spin-states of carbynes and silylynes: a long jump with one leg. J Am Chem Soc 2014; 136:13388-98. [PMID: 25152996 DOI: 10.1021/ja5073993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The challenge motivating this paper is to induce, by chemical substitution, a silylyne, SiR, or a congeneric carbyne, CR, to adopt the high-spin quartet rather than the low-spin doublet as its ground state. The difficulty is seen in the preference for the doublet of the parent SiH (doublet-quartet energy difference ∼39 kcal/mol, favoring the doublet) or CH (∼17 kcal/mol). Strategies for having high-spin ground state parallel those for silylenes and carbenes: greater electropositivity (σ-donation) and π-acceptance of the single substituent favor the high-spin state. The electronegativity trend can be understood from an ions in molecules way of thinking already present in the literature in the works of Boldyrev and Simons, and of Mavridis and Harrison; i.e., the quartet ground state spin of some CR/SiR species is largely determined by the ground state spin of C(-)/Si(-). In this study, we provide a diabatization analysis that solidly confirms the ions in molecules picture and explains the difference in the equilibrium internuclear distances for the two spin states. In general, electronegativity dominates the ordering of spin states. π-Acceptors also help to lower the quartet state energy of the many carbynes (silylynes) examined, whose range of doublet-quartet differences calculated is impressive, 120 (100) kcal/mol. The qualitative understanding gained leads to the prediction of some quartet-ground state carbynes (CMgH, CAlH2, CZnH, CSiH3, CSiF3, etc.) and a smaller number of silylynes (SiMgH, SiMgF, SiBeH, etc.). A beginning is made on the energetics of approach geometries of the fragments in the highly exoergic dimerization of CH to acetylene; it should proceed for the ground state doublet CH through C2h-like trajectories, with no activation energy.
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Affiliation(s)
- Tao Zeng
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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LI L, SUN M, LI XH, ZHAO ZW, MA HM, GAN HY, LIN ZH, SHI SC, Ziurys LM. Recent Advances on Rotational Spectroscopy and Microwave Spectroscopic Techniques. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2014. [DOI: 10.1016/s1872-2040(14)60767-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rayón VM, Redondo P, Barrientos C, Largo A. Structure and bonding in third-row main group dicarbides C2X (X=K–Br). J Chem Phys 2010; 133:124306. [PMID: 20886931 DOI: 10.1063/1.3470102] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Víctor M Rayón
- Departamento de Química Física y Química Inorgánica, Computational Chemistry Group, Facultad de Ciencias, Universidad de Valladolid, 47011 Valladolid, Spain
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