AI Article Synopsis

Article Abstract

The family of complexes of general formula [Co(Me tpa)(Xdiox)] (tpa = tris(2-pyridylmethyl)amine, n = 0-3 corresponds to successive methylation of the 6-position of the pyridine rings; X = Br, Cl, H, 3,5-Me, 3,5- tBu; diox = dioxolene) was investigated by density functional theory (DFT) calculations to predict the likelihood of valence tautomerism (VT). The OPBE functional with relativistic and solvent corrections allowed accurate reproduction of trends in spin-state energetics, affording the prediction of VT in complex [Co(Metpa)(Brdiox)] (1). One-electron oxidation of neutral precursor [Co(Metpa)(Brcat)] (1) enabled isolation of target compounds 1(PF) and 1(BPh). Solution variable-temperature UV-vis absorption and Evans method magnetic susceptibility data confirm DFT predictions that 1 exists in a temperature-dependent valence tautomeric equilibrium between low-spin Co(III)-catecholate and high-spin Co(II)-semiquinonate forms. The solution VT transition temperature of 1 is solvent-tunable with critical temperatures in the range of 291-359 K for the solvents measured. Solid-state magnetic susceptibility measurements of 1(PF) and 1(BPh) reveal the onset of VT transitions above room temperature.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.8b03291DOI Listing

Publication Analysis

Top Keywords

valence tautomerism
8
1pf 1bph
8
magnetic susceptibility
8
dft prediction
4
prediction experimental
4
experimental investigation
4
investigation valence
4
tautomerism cobalt-dioxolene
4
cobalt-dioxolene complexes
4
complexes family
4

Similar Publications

Pd(0)/Pd(II) Electromerism Triggered by Lewis Base Coordination to a Redox-Active Silicon Z-Type Ligand.

Angew Chem Int Ed Engl

December 2024

Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.

Electromerism (aka. valence tautomerism) corresponds to the switching of electronic distributions between redox-active ligands and central elements. While this phenomenon is well established for several transition metals, the Pd(0)/Pd(II) couple could not yet be involved due to the high energy of the Pd(0) state.

View Article and Find Full Text PDF

Coordination networks based on lanthanide ions entangle collective magnetic phenomena, otherwise only observed in inorganic 4f materials, and the tunable spatial and electronic structure engineering intrinsic to coordination chemistry. In this review, we discuss the use of 2D-structure-directing linear {LnI} nodes to direct the formation of polymeric coordination networks. The equatorial coordination plasticity of {LnI} results in broad structural diversity, including previously unobtainable tessellations containing motifs observed in quasicrystalline tilings.

View Article and Find Full Text PDF

Expression of concern for 'Valence tautomeric interconversion of bis-dioxolene cobalt complex with imino-pyridine functionalized by TEMPO moiety in solid solutions with isostructural nickel analogue: phase transitions and monocrystal destruction' by Michael P. Bubnov , , 2024, , 9151-9160, https://doi.org/10.

View Article and Find Full Text PDF

The thermal electrocyclic ring opening of fused -cyclobutene to ,-diene is prohibited according to the Woodward-Hoffmann (WH) rules; nonetheless, experiments provide firm evidence for their formation. However, the mechanism, electronic structure, and behavior during the reaction are ambiguous. Herein, we attempt to gain insights into the mechanism of thermal ring opening in four -heterocycles containing a conjugated diene as the core skeleton.

View Article and Find Full Text PDF

Molecules that can reversibly switch between electronic states under an external stimulus are of interest to numerous applications. Complexes of open shell metal ions with redox active ligands undergo valence tautomerism, resulting in magnetic, colour and structural switching, relevant to data storage and actuators. However, the precise structural changes occurring during valence tautomerism in the solid state are unclear due to the lack of atomic-resolution characterization.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!