TY - JOUR
T1 - Magnetic properties and pH-controlled reversible interconversion of µ-oxido into µ-hydroxido in oxo-carboxylato bridged iron(III) dimers
T2 - Theoretical and experimental insights
AU - Richa,
AU - Kumar, Akhilesh
AU - Verma, Indresh
AU - Garg, Pankaj
AU - Erande, Rohan D.
AU - Javed, Saleem
AU - Rajput, Amit
AU - Garcia, Carlos J.Gomez
AU - Mota, Antonio J.
AU - Arora, Himanshu
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/8/5
Y1 - 2023/8/5
N2 - Three dinuclear complexes of formula [FeIII2(µ-O)(µ-OOCR)(L)2](ClO4)·G, with R/G=H/(EtOAc)2 (1·2EtOAc), CH3/(Et2O)2 (2·2Et2O) and C6H5/(CH3OH)2(CH3CN)2 (3·2CH3OH·2CH3CN), [where HL = 2-((((1-methylbenzimidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenol] have been prepared. The ligand provides a N,N,N,O donor set in its deprotonated form. X-ray diffraction analyses revealed that the complexes have a similar oxido-carboxylato-bridged structure where each metal ion has a tertiary amine, one imidazolyl N atom, one pyridyl N atom and a phenolate O atom as terminal coordination. Thus, each metal centre assumes a FeIIIN3O3 coordination in an octahedral environment. Addition of acid lead to the generation of similar dinuclear complexes formulated as [FeIII2(µ-OH)(µ-OOCR)(L)2](ClO4)2, with R=H (1H), CH3 (2H) and C6H5 (3H) in solution. This protonation of the µ-O bridge is reversible and addition of base regenerates the original complexes (1–3). Magnetic measurements showed intramolecular antiferromagnetic Fe···Fe interactions in compounds 1–3 with J = ‒276(1), ‒197(1) and ‒190(1) cm−1, respectively. DFT/B3LYP calculation helped us to explicitly state the sign and magnitude of the magnetic coupling constants along with an approaching to the spin density distribution.
AB - Three dinuclear complexes of formula [FeIII2(µ-O)(µ-OOCR)(L)2](ClO4)·G, with R/G=H/(EtOAc)2 (1·2EtOAc), CH3/(Et2O)2 (2·2Et2O) and C6H5/(CH3OH)2(CH3CN)2 (3·2CH3OH·2CH3CN), [where HL = 2-((((1-methylbenzimidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenol] have been prepared. The ligand provides a N,N,N,O donor set in its deprotonated form. X-ray diffraction analyses revealed that the complexes have a similar oxido-carboxylato-bridged structure where each metal ion has a tertiary amine, one imidazolyl N atom, one pyridyl N atom and a phenolate O atom as terminal coordination. Thus, each metal centre assumes a FeIIIN3O3 coordination in an octahedral environment. Addition of acid lead to the generation of similar dinuclear complexes formulated as [FeIII2(µ-OH)(µ-OOCR)(L)2](ClO4)2, with R=H (1H), CH3 (2H) and C6H5 (3H) in solution. This protonation of the µ-O bridge is reversible and addition of base regenerates the original complexes (1–3). Magnetic measurements showed intramolecular antiferromagnetic Fe···Fe interactions in compounds 1–3 with J = ‒276(1), ‒197(1) and ‒190(1) cm−1, respectively. DFT/B3LYP calculation helped us to explicitly state the sign and magnitude of the magnetic coupling constants along with an approaching to the spin density distribution.
KW - Broken symmetry
KW - DFT
KW - Dinuclear iron complexes
KW - Magnetic properties
KW - Reversible interconversion
KW - pH-controlled
UR - http://www.scopus.com/inward/record.url?scp=85151781881&partnerID=8YFLogxK
U2 - 10.1016/j.molstruc.2023.135426
DO - 10.1016/j.molstruc.2023.135426
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AN - SCOPUS:85151781881
SN - 0022-2860
VL - 1285
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
M1 - 135426
ER -