(63) W. Wang,^† C. Xu,^† Y. Fang, Y. Zhao, J. Li* and X. Wang,* End-on vs Side-on: The Isolable Diphosphene Radical Cation Stablized by 3c-3e p-Bonding with Metal, Angew. Chem. Int. Ed. 2018, DOI: 10.1002/ange.201805115.

(62) W. Wang, C. Chen, C. Shu, S. Rajca, X. Wang*, and A. Rajca*, S = 1 Tetraazacyclophane Diradical Dication with Robust Stability: a Case of Low Temperature One-Dimensional Antiferromagnetic Chain, J. Am. Chem. Soc. 2018, DOI: 10.1021/jacs.8b02415.

(61) T. Li,^† G. Tan,^† C. Cheng, Y. Zhao, L. Zhang* and X. Wang*, Syntheses, structures and theoretical calculations of stable triarylarsine radical cations, Chem. Commun. 2018, 54, 1493–1496.

(60) Y. Fang,^† L. Zhang,^† C. Cheng, Y. Zhao, M. Abe,* G. Tan,* and X. Wang*, Experimental Observation of Thermally Excited Triplet States of Heavier Group 15 Element Centered Diradical Dianions, Chem. –Eur. J. 2018, 24, 3156–3160.

(59) S. Li,^† N. Yuan,^† Y. Fang, C. Chen, L. Wang, R. Feng, Y. Zhao, H. Cui,* and X. Wang*, Studies on the Bridge Dependence of Bis(triarylamine) Diradical Dications: Long-Range π‑Conjugation and π−π Coupling Systems, J. Org. Chem. 2018, 83, 3651−3656.

(58) T. Li, C. Cheng, N. Yuan, L. Wang, C. Chen, G. Tan*, and X. Wang*, Nitrogen Analogues of o-Quinodimethane with Unexpected non-Kekulé Diradical Character, Chin. J. Chem. 2018, 36, 487－490. （Front Cover）

(57) G. Tan and X. Wang*, Isolable Radical Ions of Main-Group Elements: Structures, Bonding and Properties, Chin. J. Chem. 2018, 36, 573－586.