Molčanov Krešimir, Milašinović Valentina, Kojić-Prodić Biserka, Maltar-Strmečki Nadica, You Jiangyang, Šantić Ana, Kanižaj Lidija, Stilinović Vladimir, Fotović Luka
Department of Physical Chemistry, Rudjer Bošković Institute, Bijenička 54, Zagreb 10000, Croatia.
Department of Materials Chemistry, Rudjer Bošković Institute, Bijenička 54, Zagreb 10000, Croatia.
IUCrJ. 2022 May 28;9(Pt 4):449-467. doi: 10.1107/S2052252522004717. eCollection 2022 Jul 1.
Multicentre two-electron (mc/2e or 'pancake bonding') bonding between 7,7,8,8-tetra-cyano-quinodi-methane (TCNQ) radical anions was studied on its 14 novel salts with planar organic cations. The formal charges of the TCNQ moieties are -1/2 and -2/3, and they form mc/2e bonded dimers, trimers and tetramers which are further stacked into extended arrays. Multicentre bonding within these oligomers is characterized by short interplanar separations of 2.9-3.2 Å; distances between the oligomers are larger, typically >3.3 Å. The stacks are laterally connected by C-H⋯N hydrogen bonding, forming 2D arrays. The nature of mc/2e bonding is characterized by structural, magnetic and electrical data. The compounds are found to be semiconductors, and high conductivity [10 (Ω cm)] correlates with short interplanar distances between pancake-bonded oligomers.
研究了7,7,8,8-四氰基对苯二醌二甲烷（TCNQ）自由基阴离子之间的多中心双电子（mc/2e或“薄饼键合”）键合，该键合存在于其14种含平面有机阳离子的新型盐中。TCNQ部分的形式电荷为-1/2和-2/3，它们形成mc/2e键合的二聚体、三聚体和四聚体，这些聚体进一步堆叠成扩展阵列。这些低聚物中的多中心键合的特征是平面间间距短，为2.9 - 3.2 Å；低聚物之间的距离更大，通常>3.3 Å。这些堆叠通过C-H⋯N氢键横向连接，形成二维阵列。mc/2e键合的性质通过结构、磁性和电学数据来表征。发现这些化合物是半导体，高电导率[10（Ω·cm）]与薄饼键合的低聚物之间的短平面间距离相关。
