Cotton F Albert, Murillo Carlos A, Villagrán Dino, Yu Rongmin
Department of Chemistry and Laboratory for Molecular Structure and Bonding, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.
J Am Chem Soc. 2006 Mar 15;128(10):3281-90. doi: 10.1021/ja0582962.
Unprecedented strong electronic communication has been found in dimolybdenum pairs containing quadruply bonded Mo2(DAniF)3(+) (DAniF = N,N'-di-p-anisylformamidinate) units linked by dioxolene (C6X2O4(2-)) anions. The neutral compounds [Mo2(DAniF)3]2(C6X2O4) (1, X = H; 2, X = Cl; 3, X = NO2) and the singly oxidized products {[Mo2(DAniF)3]2(C6X2O4)Mo2}PF6 (4, X = H; 5, X = Cl) have been synthesized and characterized by X-ray crystallography and spectroscopic methods. Unusually short Mo-O distances (approximately 2.05 A for 1 and 2, and approximately 2.01 A for 4 and 5) are implicated in the remarkably strong interaction between [Mo2] units via the linkers. This leads to an extensive charge delocalization in the mixed-valence species, which is mediated by the dioxolene linker, as revealed by the large deltaE(1/2) values (763, 795, and 816 mV for 1, 2, and 3, respectively). Additional evidence for the strong electronic coupling is provided by UV-vis, NIR, and EPR spectroscopies and DFT calculations.
在含有通过二氧杂环戊二烯（C6X2O4(2-)）阴离子连接的四重键合Mo2(DAniF)3(+)（DAniF = N,N'-二对茴香基甲脒）单元的二钼对中发现了前所未有的强电子通信。已合成中性化合物[Mo2(DAniF)3]2(C6X2O4)（1，X = H；2，X = Cl；3，X = NO2）和单氧化产物{[Mo2(DAniF)3]2(C6X2O4)Mo2}PF6（4，X = H；5，X = Cl），并通过X射线晶体学和光谱方法对其进行了表征。异常短的Mo-O距离（1和2约为2.05 Å，4和5约为2.01 Å）表明[Mo2]单元之间通过连接体存在非常强的相互作用。这导致混合价态物种中广泛的电荷离域，这是由二氧杂环戊二烯连接体介导的，如大的deltaE(1/2)值（1、2和3分别为763、795和816 mV）所示。紫外可见光谱、近红外光谱、电子顺磁共振光谱和密度泛函理论计算提供了强电子耦合的额外证据。
