Cyclometalated Iron and Ruthenium Complexes Supported by a Tetradentate Ligand Scaffold with Mixed O, N, and C Donor Atoms: Synthesis, Structures, and Excited-State Properties

Law, Kwok-Chung1,2; Tang, Zhou1,2,3; Wu, Liangliang1,2; Wan, Qingyun1,2; To, Wai-Pong1,2; Chang, Xiaoyong3; Low, Kam-Hung1,2; Liu, Yungen3; Che, Chi-Ming1,2,3

2022-02-28

10.1021/acs.organomet.1c00677

ORGANOMETALLICS   影响因子和分区

0276-7333

1520-6041

A series of cyclometalated Fe(II/III) and Ru(II/III) complexes bearing a tetradentate dianionic [O<^>N<^>C<^>N] ligand (H-2[O<^>N<^>C<^>N] = 2-(6-(3-(pyridin-2-yl)phenyl)pyridin-2-yl)-phenol) was synthesized and structurally characterized. The strong-field dianionic [O<^>N<^>C<^>N] ligand enforces all of these complexes in a low-spin state at 298 K as revealed by H-1 NMR, magnetic susceptibility, and electron paramagnetic resonance (EPR) measurements. A 77 K 2-MeTHF (THF = tetrahydrofuran) glassy solution of the bis(2,6-dimethylphenyl isocyanide) Ru(II) complex [Ru-II(O<^>N<^>C<^>N)(XylNC)(2)] displays a weak and broad emission band (lambda(em): 680 nm; tau: 0.27 mu s), while the others are nonemissive. Density functional theory (DFT)/time-dependent DFT calculations revealed that (1)dd excited states of the d(6) [M-II(O<^>N<^>C<^>N)(PMe3)(2)] (M = Fe, Ru) are strongly destabilized. The [Fe-II(O<^>N<^>C<^>N)(PMe3)(2)] exhibits panchromatic absorption up to 850 nm. A combined study of femtosecond transient absorption (fs-TA), spectro-electrochemistry, and theoretical calculation revealed that the possible triplet metal-to-ligand charge transfer ((MLCT)-M-3) excited state (tau: 14 ps) of [Fe-II(O<^>N<^>C<^>N)(PMe3)(2)] decays via a lower-lying (3)dd excited state. For the d(5) [M-III(O<^>N<^>C<^>N)(PMe3)(2)](+) (M = F; Ru), the presence of low-lying (2)dd excited states and doublet ligand-to-metal charge transfer ((LMCT)-L-2) states with short lifetimes tau: 11.7-12.6 ps) is suggested.

SCI ; EI

英语

通讯

Guangdong Major Program of Basic and Applied Research[2019B030302009] ; Hong Kong Research Grants Council General Research Fund[17303815,17301817] ; National Natural Science Foundation of China[NSFC 91856203] ; Shenzhen Science and Technology Innovation Commission["JCYJ20170412140251576","JCYJ20180508162429786"]

Chemistry

Chemistry, Inorganic & Nuclear ; Chemistry, Organic

WOS:000767339100006

AMER CHEMICAL SOC

20220811689737

Charge transfer ; Chelation ; Density functional theory ; Electron spin resonance spectroscopy ; Iron compounds ; Ligands ; Magnetic susceptibility ; Nuclear magnetic resonance ; Organic solvents ; Paramagnetic resonance ; Ruthenium compounds ; Scaffolds ; Synthesis (chemical)

Construction Equipment:405.1 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Chemistry:801 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Chemical Agents and Basic Industrial Chemicals:803 ; Organic Compounds:804.1 ; Probability Theory:922.1 ; Atomic and Molecular Physics:931.3 ; Quantum Theory; Quantum Mechanics:931.4

CHEMISTRY

Web of Science

1.Univ Hong Kong, State Key Lab Synthet Chem, Hong Kong, Peoples R China
2.Univ Hong Kong, Dept Chem, Hong Kong, Peoples R China
3.Southern Univ Sci & Technol, Dept Chem, Shenzhen 518055, Guangdong, Peoples R China

Law, Kwok-Chung,Tang, Zhou,Wu, Liangliang,et al. Cyclometalated Iron and Ruthenium Complexes Supported by a Tetradentate Ligand Scaffold with Mixed O, N, and C Donor Atoms: Synthesis, Structures, and Excited-State Properties[J]. ORGANOMETALLICS,2022,41(4):418-429.

Law, Kwok-Chung.,Tang, Zhou.,Wu, Liangliang.,Wan, Qingyun.,To, Wai-Pong.,...&Che, Chi-Ming.(2022).Cyclometalated Iron and Ruthenium Complexes Supported by a Tetradentate Ligand Scaffold with Mixed O, N, and C Donor Atoms: Synthesis, Structures, and Excited-State Properties.ORGANOMETALLICS,41(4),418-429.

Law, Kwok-Chung,et al."Cyclometalated Iron and Ruthenium Complexes Supported by a Tetradentate Ligand Scaffold with Mixed O, N, and C Donor Atoms: Synthesis, Structures, and Excited-State Properties".ORGANOMETALLICS 41.4(2022):418-429.