TY - JOUR
T1 - Combined Experimental and Computational Study of Pyren-2,7-diyl-Bridged Diruthenium Complexes with Various Terminal Ligands
AU - Yao, Chang Jiang
AU - Nie, Hai Jing
AU - Yang, Wen Wen
AU - Yao, Jiannian
AU - Zhong, Yu Wu
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/5/18
Y1 - 2015/5/18
N2 - Cyclometalated diruthenium complexes 1(PF6)2-5(PF6)2 bridged by 1,3,6,8-tetra(pyrid-2-yl)-pyrene have been prepared, with the terminal ligand bis(N-methylbenzimidazolyl)pyridine (1(PF6)2), 4′-di-(p-methoxyphenyl)amino-2,2′:6′,2″-terpyridine (2(PF6)2), 4′-p-methoxyphenyl-2,2′:6′,2″-terpyridine (3(PF6)2), 2,2′:6′,2″-terpyridine (4(PF6)2), and trimethyl-4,4′,4″-tricarboxylate-2,2′:6′,2″-terpyridine (5(PF6)2). The single-crystal X-ray structure of 4(PF6)2 is presented. These complexes show two stepwise anodic redox pairs, and the potentials progressively increase from 1(PF6)2 to 5(PF6)2. Complexes 1(PF6)2-4(PF6)2 have comparable electrochemical potential splitting of 200-210 mV, while complex 5(PF6)2 has a splitting of 170 mV. Upon one-electron oxidation by chemical oxidation or electrolysis, the resulting mixed-valent complexes 13+-53+ display broad and intense absorptions between 1000 and 3000 nm. Complexes 13+ and 23+ show the presence of a higher-energy shoulder band in addition to the main near-infrared absorption band. This shoulder band is less distinguished for 33+-53+. Three-state theory has been used to explain this difference. The one-electron oxidized forms, 13+-53+, exhibit rhombic EPR signals at 77 K with the isotropic g values in the range of 2.18-2.24. Density functional theory (DFT) and time-dependent DFT (TDDFT) computations have been performed on 12+-52+ to characterize their electronic structures and rationalize the absorption spectra in a wide energy range. DFT computations on 13+-53+ show that both ruthenium ions and the bridging ligand have comparable spin densities. TDDFT computations on 13+ and 43+ have been performed to complement the experimental results. (Chemical Equation Presented).
AB - Cyclometalated diruthenium complexes 1(PF6)2-5(PF6)2 bridged by 1,3,6,8-tetra(pyrid-2-yl)-pyrene have been prepared, with the terminal ligand bis(N-methylbenzimidazolyl)pyridine (1(PF6)2), 4′-di-(p-methoxyphenyl)amino-2,2′:6′,2″-terpyridine (2(PF6)2), 4′-p-methoxyphenyl-2,2′:6′,2″-terpyridine (3(PF6)2), 2,2′:6′,2″-terpyridine (4(PF6)2), and trimethyl-4,4′,4″-tricarboxylate-2,2′:6′,2″-terpyridine (5(PF6)2). The single-crystal X-ray structure of 4(PF6)2 is presented. These complexes show two stepwise anodic redox pairs, and the potentials progressively increase from 1(PF6)2 to 5(PF6)2. Complexes 1(PF6)2-4(PF6)2 have comparable electrochemical potential splitting of 200-210 mV, while complex 5(PF6)2 has a splitting of 170 mV. Upon one-electron oxidation by chemical oxidation or electrolysis, the resulting mixed-valent complexes 13+-53+ display broad and intense absorptions between 1000 and 3000 nm. Complexes 13+ and 23+ show the presence of a higher-energy shoulder band in addition to the main near-infrared absorption band. This shoulder band is less distinguished for 33+-53+. Three-state theory has been used to explain this difference. The one-electron oxidized forms, 13+-53+, exhibit rhombic EPR signals at 77 K with the isotropic g values in the range of 2.18-2.24. Density functional theory (DFT) and time-dependent DFT (TDDFT) computations have been performed on 12+-52+ to characterize their electronic structures and rationalize the absorption spectra in a wide energy range. DFT computations on 13+-53+ show that both ruthenium ions and the bridging ligand have comparable spin densities. TDDFT computations on 13+ and 43+ have been performed to complement the experimental results. (Chemical Equation Presented).
UR - http://www.scopus.com/inward/record.url?scp=84929646236&partnerID=8YFLogxK
U2 - 10.1021/ic503117k
DO - 10.1021/ic503117k
M3 - Article
AN - SCOPUS:84929646236
SN - 0020-1669
VL - 54
SP - 4688
EP - 4698
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 10
ER -