Ruthenium-Amine Electronic Coupling Bridged through Phen-1,3-diyl Versus Phen-1,4-diyl: Reverse of the Charge Transfer Direction

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• 作者：Jian-Hong Tang ; Si-Hai Wu ; Jiang-Yang Shao ; Hai-Jing Nie ; Yu-Wu Zhong
• 刊名：Organometallics
• 出版年：2013
• 出版时间：August 26, 2013
• 年：2013
• 卷：32
• 期：16
• 页码：4564-4570
• 全文大小：372K
• 年卷期：v.32,no.16(August 26, 2013)
• ISSN：1520-6041

文摘

Three tris-bidentate cyclometalated ruthenium complexes with a di(p-anisyl)amino [5(PF₆)], di(p-tolyl)amino [6(PF₆)], or di(p-chlorophenyl)amino [7(PF₆)] substituent on the cyclometalating phenyl ring have been prepared, where the amine nitrogen is in the meta position to the cyclometalated site (bridged through the phen-1,3-diyl unit). The structure of 6(PF₆) has been confirmed by single-crystal X-ray diffraction analysis. Two consecutive redox waves are evident at +0.48 and +0.87 V versus Ag/AgCl for 5(PF₆), +0.51 and +1.02 V for 6(PF₆), and +0.53 and +1.18 V for 7(PF₆), respectively. The first wave is assigned to the Ru(II/III) process, and the second wave is attributed to the N(0/+) process. After one-electron oxidation using SbCl₅, these complexes display distinct absorptions in the near-infrared region, which are assigned to the nitrogen-to-ruthenium intervalence charge-transfer (ICVT) transitions. The energies of the IVCT transitions vary linearly versus the potential splitting of the Ru(II/III) and N(0/+) process. The charge-transfer direction in these complexes is reversed with respect to a previously reported ruthenium鈥揳mine system where the amine nitrogen is in the para position to the cyclometalated site (bridged through the phen-1,4-diyl unit).