Two types of nitrito support for μ4-oxido-bridged [Cu4] complexes: synthesis, crystal structures, magnetic properties and DFT analysis
| Autor: | Michael Shatruk, Silvia Gómez-Coca, Moumita Pait, Debashis Ray, Antonio Frontera, Jeff Lengyel, Valerio Bertolasi, Antonio Bauzá |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Aggregates
Magnetic couplings Magnetic susceptibility measurements Ground state X ray crystal structures Numerical fitting Crystal structure Ligands Spectroscopic analysis NO Chiral Schiff-base Inorganic Chemistry Magnetic susceptibility chemistry.chemical_compound Antiferromagnetic exchange interactions Antiferromagnetism Aggregates Crystal structure Density functional theory Electric measuring bridges Functional groups Ground state Ligands Magnetic couplings Magnetic susceptibility Nitrogen oxides Spectroscopic analysis Synthesis (chemical) Antiferromagnetic exchange interactions Chiral Schiff-base Magnetic susceptibility measurements Numerical fitting Tetranuclear clusters Tetranuclear complexes Variable temperature X ray crystal structures Tetranuclear clusters Schiff base Electric measuring bridges Chemistry Variable temperature Inductive coupling Crystallography Intramolecular force Synthesis (chemical) Density functional theory Functional groups Tetranuclear complexes Nitrogen oxides |
| Popis: | Novel nitrito supported and μ4-oxido bridged CuII aggregates have been found in two tetranuclear complexes, [Cu4(μ4-O)L2(μ1,3-ONO)4] (1) and [Cu4(μ4-O)L2(μ1,3-OAc)2(μ1,2-NO2)2] (2), of the chiral Schiff base HL (HL = 4-methyl-2,6-bis-(1-phenyl-ethylimino)-methylphenol). The structures contain either in situ generated or externally added peripheral μ-nitrito groups, in κ2O/O and κ2N/O bridging modes. Four NO2− bridges in 1 and two AcO− co-ligands along with two NO2− bridges in 2 are essential for the stabilization of these tetranuclear aggregates. The complexes have been characterized by X-ray crystal structure determination, spectroscopic and magnetic measurements, and density functional theory (DFT) analysis. They are formed from the assembly of two [Cu2L]3+ fragments around a water-derived oxido ligand under the control of nitrite or mixed nitrite/acetate bridges. Variable temperature magnetic susceptibility measurements reveal strong intramolecular antiferromagnetic exchange interactions within the tetranuclear clusters to yield ST = 0 ground state. The capacity of the two different nitrite bridging modes to mediate magnetic coupling has been examined through measurements and numerical fitting procedures, and rationalized by means of DFT calculations. |
| Databáze: | OpenAIRE |
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