TY - JOUR
T1 - Electronic coupling between two amine redox sites through the 5,5'-positions of metal-chelating 2,2'-bipyridines
AU - Nie, Hai Jing
AU - Chen, Xialing
AU - Yao, Chang Jiang
AU - Zhong, Yu Wu
AU - Hutchison, Geoffrey R.
AU - Yao, Jiannian
PY - 2012/11/5
Y1 - 2012/11/5
N2 - Electron delocalization of new mixed-valent (MV) systems with the aid of lateral metal chelation is reported. 2,2'-Bipyridine (bpy) derivatives with one or two appended di-p-anisylamino groups on the 5,5'-positions and a coordinated [Ru(bpy) 2] (bpy=2,2'-bipyridine), [Re(CO) 3Cl], or [Ir(ppy) 2] (ppy=2-phenylpyridine) component were prepared. The single-crystal molecular structure of the bis-amine ligand without metal chelation is presented. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic techniques and DFT/TDDFT calculations. Compounds with two di-p-anisylamino groups were oxidized by a chemical or electrochemical method and monitored by near-infrared (NIR) absorption spectral changes. Marcus-Hush analysis of the resulting intervalence charge-transfer transitions indicated that electron coupling of these mixed-valent systems is enhanced by metal chelation and that the iridium complex has the largest coupling. TDDFT calculations were employed to interpret the NIR transitions of these MV systems.
AB - Electron delocalization of new mixed-valent (MV) systems with the aid of lateral metal chelation is reported. 2,2'-Bipyridine (bpy) derivatives with one or two appended di-p-anisylamino groups on the 5,5'-positions and a coordinated [Ru(bpy) 2] (bpy=2,2'-bipyridine), [Re(CO) 3Cl], or [Ir(ppy) 2] (ppy=2-phenylpyridine) component were prepared. The single-crystal molecular structure of the bis-amine ligand without metal chelation is presented. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic techniques and DFT/TDDFT calculations. Compounds with two di-p-anisylamino groups were oxidized by a chemical or electrochemical method and monitored by near-infrared (NIR) absorption spectral changes. Marcus-Hush analysis of the resulting intervalence charge-transfer transitions indicated that electron coupling of these mixed-valent systems is enhanced by metal chelation and that the iridium complex has the largest coupling. TDDFT calculations were employed to interpret the NIR transitions of these MV systems.
KW - N ligands
KW - chelates
KW - density functional calculations
KW - donor-acceptor systems
KW - mixed-valent compounds
UR - http://www.scopus.com/inward/record.url?scp=84868028795&partnerID=8YFLogxK
U2 - 10.1002/chem.201201813
DO - 10.1002/chem.201201813
M3 - Article
AN - SCOPUS:84868028795
SN - 0947-6539
VL - 18
SP - 14497
EP - 14509
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 45
ER -