Complete active space self-consistent field (CASSCF) wavefunctions and an orbital entanglement analysis obtained from a density-matrix renormalisation group (DMRG) calculation are used to understand the electronic structure, and, in particular, the Ru-NO bond of a Ru nitrosyl complex. Based on the configurations and orbital occupation numbers obtained for the CASSCF wavefunction and on the orbital entropy measurements evaluated for the DMRG wavefunction, we unravel electron correlation effects in the Ru coordination sphere of the complex. It is shown that Ru-NO π bonds show static and dynamic correlation, while other Ru-ligand bonds feature predominantly dynamic correlation. The presence of static correlation requires the use of multiconfigurational methods to describe the Ru-NO bond. Subsequently, the CASSCF wavefunction is analysed in terms of configuration state functions based on localised orbitals. The analysis of the wavefunctions in the electronic singlet ground state and the first triplet state provides a picture of the Ru-NO moiety beyond the standard representation based on formal oxidation states. A distinct description of the Ru and NO fragments is advocated. The electron configuration of Ru is an equally weighted superposition of Ru(II) and Ru(III) configurations, with the Ru(III) configuration originating from charge donation mostly from Cl ligands. However, and contrary to what is typically assumed, the electronic configuration of the NO ligand is best described as electroneutral.
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http://dx.doi.org/10.1039/c4cp05278a | DOI Listing |
Dalton Trans
November 2024
Université de Lorraine, CNRS, CRM2, UMR 7036, Nancy 54000, France.
A new nitro-nitrosyl complex [RuNO(Phen)(NO)OH] (1) was synthesized and characterized by X-ray diffraction, where Phen = 1,10-phenanthroline. The complex was crystallized in two different modifications without (1) and with a solvent molecule of DMF (1a). The photolysis process together with the determination of the quantum yield of NO release was investigated in acetonitrile solution using a special flow-through system for the simultaneous registration of infrared (IR) and optical absorption (UV-vis) spectra under irradiation with 450 nm light.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Université de Lorraine, CNRS, CRM2, UMR 7036, Nancy 54000, France.
X-ray absorption spectroscopy (XAS) is a powerful tool for examining changes of the electronic and molecular structure following light-induced excitation of a molecule. Specifically, this method can be applied to investigate the ground (GS, RuNO) and metastable states (MS1, RuON and MS2, Ruη(NO)) of the nitrosyl ligand (NO), which differ in their coordination mode to the metal. In this work, we report for the first time experimental and theoretical (DFT) Ru L,-edge XA spectra for the octahedral complex trans-[RuNOPyF](ClO) (1, Py = pyridine) in both ground and metastable states.
View Article and Find Full Text PDFChem Asian J
January 2024
Department of Chemistry and Green-Nano Research Center, Kyungpook National University, Daegu, 41566, Republic of Korea.
In this study, we introduced the electron-donating group (-OH) to the aromatic rings of Ru(salophen)(NO)Cl (0) (salophenH =N,N'-(1,2-phenylene)bis(salicylideneimine)) to investigate the influence of the substitution on NO photolysis and NO-releasing dynamics. Three derivative complexes, Ru((o-OH) -salophen)(NO)Cl (1), Ru((m-OH) -salophen)(NO)Cl (2), and Ru((p-OH) -salophen)(NO)Cl (3) were developed and their NO photolysis was monitored by using UV/Vis, EPR, NMR, and IR spectroscopies under white room light. Spectroscopic results indicated that the complexes were diamagnetic Ru(II)-NO species which were converted to low-spin Ru(III) species (d , S=1/2) and released NO radicals by photons.
View Article and Find Full Text PDFDalton Trans
January 2023
Université de Lorraine, CNRS, CRM2, UMR 7036, Nancy 54000, France.
The first examples of Bi(III) and Sb(III) halide compounds combined with a photoswitchable ruthenium nitrosyl unit are reported. The structures of [RuNOPyBr][SbBr][SbBr] (1) and (HO)[RuNOPyBr][BiBr]·3HO (2) were determined by X-ray diffraction, and exhibit three different structural types of group 15 halometalates. Low-temperature IR-spectroscopy measurements reveal that the irradiation of 1 at 365 nm switches a stable Ru-NO (GS) unit to a metastable Ru-ON (MS1) linkage.
View Article and Find Full Text PDFDalton Trans
April 2022
University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria.
The synthesis of new types of mono- and polynuclear ruthenium nitrosyl complexes is driving progress in the field of NO generation for a variety of applications. Light-induced Ru-NO bond dissociation in solution may involve transient linkage isomers MS1 (Ru-ON) and MS2 (Ru-η-NO), which can be detected spectroscopically and analyzed computationally. The investigation of photoisomerization processes in the solid state may be useful for potential application of such complexes for data storage, photochromic or photomagnetic materials or even non-linear optics.
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