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1. PrB ₇ ⁻ : A Praseodymium-Doped Boron Cluster with a Pr ^II Center Coordinated by a Doubly Aromatic Planar η ⁷ -B ₇ ³⁻ Ligand

   https://doi.org/10.1002/anie.201703111  

   Chen, Teng-Teng ; Li, Wan-Lu ; Jian, Tian ; Chen, Xin ; Li, Jun ; Wang, Lai-Sheng ( June 2017 , Angewandte Chemie International Edition)
2. PrB ₇ ⁻ : A Praseodymium‐Doped Boron Cluster with a Pr ^II Center Coordinated by a Doubly Aromatic Planar η ⁷ ‐B ₇ ³⁻ Ligand

   https://doi.org/10.1002/ange.201703111  

   Chen, Teng‐Teng ; Li, Wan‐Lu ; Jian, Tian ; Chen, Xin ; Li, Jun ; Wang, Lai‐Sheng ( May 2017 , Angewandte Chemie)
3. The smallest 4f-metalla-aromatic molecule of cyclo-PrB ₂ ⁻ with Pr–B multiple bonds

   https://doi.org/10.1039/D2SC02852B  

   Wang, Zhen-Ling ; Chen, Teng-Teng ; Chen, Wei-Jia ; Li, Wan-Lu ; Zhao, Jing ; Jiang, Xue-Lian ; Li, Jun ; Wang, Lai-Sheng ; Hu, Han-Shi ( August 2022 , Chemical Science)

   The concept of metalla-aromaticity proposed by Thorn–Hoffmann ( Nouv. J. Chim . 1979, 3, 39) has been expanded to organometallic molecules of transition metals that have more than one independent electron-delocalized system. Lanthanides, with highly contracted 4f atomic orbitals, are rarely found in multiply aromatic systems. Here we report the discovery of a doubly aromatic triatomic lanthanide-boron molecule PrB 2 − based on a joint photoelectron spectroscopy and quantum chemical investigation. Global minimum structural searches reveal that PrB 2 − has a C 2v triangular structure with a paramagnetic triplet 3 B 2 electronic ground state, which can be viewed as featuring a trivalent Pr(III,f 2 ) and B 2 4− . Chemical bonding analyses show that this cyclo-PrB 2 − species is the smallest 4f-metalla-aromatic system exhibiting σ and π double aromaticity and multiple Pr–B bonding characters. It also sheds light on the formation of the rare B 2 4− tetraanion by the high-lying 5d orbitals of the 4f-elements, completing the isoelectronic B 2 4− , C 2 2− , N 2 , and O 2 2+ series.
4. Quantum-vibrational-state-selected Integral Cross Sections and Product Branching Ratios for the Ion-molecule Reactions of N ₂ ⁺ ( X ² Σ _g ⁺ ; v ⁺ = 0–2) + H ₂ O and H ₂ O ⁺ ( X ² B ₁ : v ₁ ⁺ v ₂ ⁺ v ₃ ⁺ = 000 and 100) + N ₂ in the Collision Energy Range of 0.04–10.00 eV

   https://doi.org/10.3847/1538-4357/aac9bf  

   Xu, Yuntao ; Xiong, Bo ; Chang, Yih Chung ; Ng, Cheuk-Yiu ( July 2018 , The Astrophysical Journal)
5. Synthesis and Characterization of Non-Aqueous [Tc ^X M-PW ₁₁ O ₃₉ ] ^{n -} with M = O, N: Comparing Tc ^V and Tc ^VI in Metal Oxide Matrices: Synthesis and Characterization of Non-Aqueous [Tc ^X M-PW ₁₁ O ₃₉ ] ^{n -} with M = O, N: Comparing Tc ^V and Tc ^VI in Metal Oxide Matrices

   https://doi.org/10.1002/ejic.201900864  

   Burton-Pye, Benjamin P. ; Dembowski, Mateusz ; Lukens, Jr., Wayne W. ; Cruz, Anthony ; Althour, Alrasheed ; Lopez, Gustavo E. ; Salcedo, Ramsey ; Gallagher, Colleen M. B. ; McGregor, Donna ; Francesconi, Lynn C. ( November 2019 , European Journal of Inorganic Chemistry)