博彩平台

CaY@C_2n : Exploring Molecular Qubits with Ca-Y Metal-Metal Bonds

Jiawei Qiu^1,2, Laura Abella³, Xiya Du^4,5,6, Zhengkai Cao^1,2, Zhiwen He^1,2, Qingyu Meng^1,2, Yingjing Yan^1,2, Josep M. Poblet³, Lei Sun^4,5,6,7（孙磊）*, Antonio Rodríguez-Fortea³*, Ning Chen^1,2（谌宁）*

¹College of Chemistry, Chemical Engineering, Soochow University, Suzhou,Jiangsu 215123, P.R. China

²Materials Science and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu 215123, P.R. China

³Departament de Química Física i Inorgànica,Universitat Rovira i Virgili, Tarragona 43007, Spain

⁴Department of Chemistry, School of Science and Research Center for Industries of the Future, WestlakeUniversity, Hangzhou, Zhejiang Province 310030, China

⁵Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang Province 310024, China

⁶Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang Province 310030, China;

⁷Key Laboratory for Quantum Materials of Zhejiang Province,Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang Province 310030, China

J. Am. Chem. Soc. 2024, 146, 35, 24310–24319

Abstract: Metal–metal bonding is crucial in chemistry for advancing our understanding of the fundamental aspects of chemical bonds. Metal–metal bonds based on alkaline-earth (Ae) elements, especially the heavier Ae elements (Ca, Sr, and Ba), are rarely reported due to their high electropositivity. Herein, we report two heteronuclear di-EMFs CaY@C_s(6)-C₈₂ and CaY@C_2v(5)-C₈₀, which contain unprecedented single-electron Ca–Y metal–metal bonds. These compounds were characterized by single-crystal X-ray crystallography, electron paramagnetic resonance (EPR) spectroscopy, and DFT calculations. The crystallographic study of CaY@Cs(6)-C₈₂ shows that Ca and Y are successfully encapsulated into the carbon cage with a Ca–Y distance of 3.691 Å. The CW-EPR study of both CaY@Cs(6)-C₈₂ and CaY@C_2v(5)-C₈₀ exhibits a doublet, suggesting the presence of an unpaired electron located between Ca and Y. The combined experimental and theoretical results confirm the presence of a Ca–Y single-electron metal–metal bond with substantial covalent interaction, attributed to significant overlap between the 4s4p orbitals of Ca and the 5s5p4d orbitals of Y. Furthermore, pulse EPR spectroscopy was used to investigate the quantum coherence of the electron spin within this bond. The unpaired electron, characterized by its s orbital nature, is effectively protected by the carbon cage, resulting in efficient suppression of both spin–lattice relaxation and decoherence. CaY@Cs(6)-C₈₂ behaves as an electron spin qubit, displaying a maximum decoherence time of 7.74 μs at 40 K. This study reveals an unprecedented Ae–rare-earth metal–metal bond stabilized by the fullerene cages and elucidates the molecular qubit properties stemming from their unique bonding character, highlighting their potential in quantum information processing applications.

链接：//pubs.acs.org/doi/10.1021/jacs.4c04720