Control of the Charge Distribution and Modulation of the Class II-III Transition in Weakly Coupled Mo-2-Mo-2 Systems

CORC > 厦门大学 > 化学化工－已发表论文

	Control of the Charge Distribution and Modulation of the Class II-III Transition in Weakly Coupled Mo-2-Mo-2 Systems
	Xiao, Xuan ; Liu, Chun Y. ; He, Qiao ; Han, Mei Juan ; Meng, Miao ; Lei, Hao ; Lu, Xin ; He Q(何桥)
刊名	http://dx.doi.org/10.1021/ic4017855
	2013
关键词	CONNECTING DIMOLYBDENUM REDOX ELECTRON-TRANSFER REACTIONS MIXED-VALENCE QUADRUPLE BONDS CHROMOPHORIC CENTERS RUTHENIUM AMMINES MOLECULAR PAIR COMPLEXES UNITS ENERGY
英文摘要	National Natural Science Foundation of China [20871093, 90922010]; Tongji University; Jinan University; Sun Yat-Sen University; Three novel dimolybdenum dimers [Mo-2(DAniF)(3)](2)(mu-OSCC6H4CSO), [Mo-2(DAniF)(3)](2)(mu-O2CC6H4CS2), and [Mo-2(DAniF)(3)](2)(mu-S2CC6H4CS2) (DAniF = N,N'-di(p-anisyl) formamidinate) have been synthesized and characterized by single-crystal X-ray diffractions. Together with the terephthalate analogue, the four compounds, denoted as [O-2-O-2], [OS-OS], [S-2-S-2], and [O-2-S-2], have similar molecular skeletons and Mo-2 center dot center dot center dot Mo-2 separations (similar to 12 angstrom), but varying sulfur contents or symmetry. The singly oxidized complexes [O-2-O-2](+), [OS-OS](+), [S-2-S-2](+), and [O-2-S-2](+) display characteristic intervalence transition absorption bands in the near- and mid-IR regions, with differing band energy, intensity, and shape. Applying the geometrical length of the bridging group "-CC6H4C-" (5.8 angstrom) as the effective electron transfer distance, calculations from the Mulliken-Hush equation yield electronic coupling matrix elements (H-ab) in the range 600-900 cm(-1). Significantly, this series presents a transition from electron localization to "almost-delocalization" as the carboxylate groups of the bridging ligand are successively thiolated. In terms of Robin-Day's scheme, [S-2-S-2](+) is best described as an intermediate between Class II and III, while [O-2-O-2](+) and [OS-OS](+) belong to Class II. It is unusual that the Class II-III transition occurs in such a weakly coupled system (H-ab < 1000 cm(-1)). This is attributed to the d(delta)-p(pi) conjugation between the Mo-2 center and bridging ligand. By electrochemical and spectroscopic methods, the internal energy difference for [O-2-S-2](+) is determined to be 2250 +/- 80 cm(-1), which controls the charge distribution of the cation radical. The experimental results and theoretical analyses illustrate that the unsymmetrical geometry leads to unbalanced electronic configurations and asymmetrical redox and optical behaviors.
语种	英语
出版者	AMER CHEMICAL SOC
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/88829]
专题	化学化工－已发表论文
推荐引用方式 GB/T 7714	Xiao, Xuan,Liu, Chun Y.,He, Qiao,et al. Control of the Charge Distribution and Modulation of the Class II-III Transition in Weakly Coupled Mo-2-Mo-2 Systems[J]. http://dx.doi.org/10.1021/ic4017855,2013.
APA	Xiao, Xuan.,Liu, Chun Y..,He, Qiao.,Han, Mei Juan.,Meng, Miao.,...&何桥.(2013).Control of the Charge Distribution and Modulation of the Class II-III Transition in Weakly Coupled Mo-2-Mo-2 Systems.http://dx.doi.org/10.1021/ic4017855.
MLA	Xiao, Xuan,et al."Control of the Charge Distribution and Modulation of the Class II-III Transition in Weakly Coupled Mo-2-Mo-2 Systems".http://dx.doi.org/10.1021/ic4017855 (2013).