Easing Intermediates Search by Combining Spectroscopy and Multivariate Curve Reconstruction: [CuI(6,6'-dimethyl-2,2'-bipyridyl)2]PF6 Oxidation as Case Study

Despite their prevalence in catalysis, complex reaction mixtures are not trivial to investigate and disentangle. Different approaches can be applied to characterize them, even featuring low-dimensionality data sets. The liquid-phase reaction of [CuI(6,6'-dimethyl-2,2'-bipyridyl)2]PF6 (CuI) with tert-butyl hydroperoxide is investigated: two CuII species are found upon oxidation of the pristine complex, characterized by different spectroscopic and kinetics fingerprints. Coupling EPR and UV-vis spectroscopies with chemometric methods (namely, multivariate curve reconstruction, MCR) allowed for easily retrieving pure spectral features and concentration profiles. Spectrokinetic analysis independently showed an optimal agreement with kinetic outcomes from MCR. Finally, hypotheses on the nature of the CuII species are drawn on the basis of EPR fitting and quantum chemistry computations on a series of candidate structures. Beyond the accurate characterization of a model system, this study demonstrates the potential of coupling multivariate statistical techniques, experiments, and computations toward a quantitative understanding of electronic and kinetic information on complex chemical systems.

Synthesis, characterization and multi-dimensional application approach for two distinctive tetra nuclear, first-time reported, Fe3+/Hg2+ and Fe3+/Cd2+ clusters from a new Fe3+ containing metalloligand

Synthesis of two unique μ oxo-bridged complexes MC2 and MC3 from a metalloligand MC1 results to efficient dye degradation efficacy and effective schottkey device.

Recent reports on Pyridoxal derived Schiff base complexes

Pyridoxal and Pyridoxal 5-phosphate are two among the six aqua soluble vitamers of vitamin B6. They can form Schiff bases readily due to the presence of aldehyde group. Schiff bases can offer diverse coordination possibilities for many transition metals as has been found in a large volume of research till now. The coordination complexes thus formed gives insight into the active core structure and enzymatic activities of vit B6 containing enzymes. Apart from that, these complexes have been found useful as catalysts for synthesis of fine chemicals, as sensors and for their diverse biological activities.

Mono-, tri- and polynuclear copper(ii) complexes of Schiff-base ligands: synthesis, characterization and catalytic activity towards alcohol oxidation

A mononuclear copper(ii) complex acts as a superior catalyst compared to a tri- or polynuclear complex towards oxidation of alcohols to the corresponding aldehydes.

A graphene oxide immobilized Cu(ii) complex of 1,2-bis(4-aminophenylthio)ethane: an efficient catalyst for epoxidation of olefins with tert-butyl hydroperoxide

Alkene epoxidation with tert-butyl hydroperoxide catalyzed by the Cu(ii) dithiol complex supported on graphene oxide is reported.

Unique trapping of paddlewheel copper(ii) carboxylate by ligand-bound {Cu2} fragments for [Cu6] assembly

Trapping of paddlewheel {Cu₂(carboxylate)₄} by ligand-bound {Cu₂(μ-H₂L)}³⁺ units resulted in dumbbell-shaped [Cu₆] complexes modulating the tetracarboxylate bridged Cu⋯Cu separations.

Novel CuII–MII–CuII (M = Cu or Ni) trinuclear and [NaI2CuII6] hexanuclear complexes assembled by bi-compartmental ligands: syntheses, structures, magnetic and catalytic studies

Complexes 5–7 synthesized from two in situ generated ligands, HL¹ and HL² exhibited excellent TON for epoxidation of olefins.

Two types of nitrito support for μ4-oxido-bridged [Cu4] complexes: synthesis, crystal structures, magnetic properties and DFT analysis

In situ generated NO₂⁻ and externally added NO₂⁻ and AcO⁻ ions have been utilized for the isolation of μ₄-oxido-bridged Cu₄ aggregates showing magnetic coupling which can be rationalized by DFT calculations.

Mono- and tetra-nuclear copper complexes bearing bis(imino)phenoxide derived ligands: catalytic evaluation for benzene oxidation and ROP of ε-caprolactone

Mono- and tetra-nuclear copper bis(imino)phenoxide complexes have been evaluated as catalysts for benzene oxidation and ROP of ε-caprolactone.

Novel tetranuclear Ni(II) Schiff base complex containing Ni4O4 cubane core: synthesis, X-ray structure, spectra and magnetic properties

Novel tetranuclear nickel(II) Schiff base complex having symmetric Ni4O4 cubane-core, [Ni4O2(OAc)2(L)2] (1) has been synthesized. Single crystal of the complex exhibits four nickel atoms in the alternate corner of the cubane and other four sites are occupied by phenolate-O and μ3-O(2-). Variable temperature magnetic moment data suggests the Ni centres are weakly antiferromagnetically coupled with J1=-4.82cm(-1) and J2=-4.83cm(-1). The electronic spectra, emission properties and life time measurement of ligand, HL and complex 1 have been studied.

Nonelectrochemical synthesis, crystal structure, and physical properties of the radical salt [ET]2[CuCl4] (ET = bis(ethylenedithio)tetrathiafulvalene)

The radical salt [ET]2[CuCl4] was obtained by chemical oxidation of bis(ethylenedithio)tetrathiafulvalene (ET) with the tetranuclear copper(II) halide cluster [Cu4OCl10](4-). Although a complex mixture of anions forms in solution during the redox reaction, only this product is obtained as large (>3 mm) single crystals. X-ray diffraction analysis determined that the ET molecules stack in the solid state forming dimerized 1D chains along the a axis, interleaved by [CuCl4](2-) anions. The ET dimers show very short S···S contacts (<3.41 Å). The physical properties are dominated by these intradimer ET interactions. The magnetic behavior shows antiferromagnetic coupling with a singlet-triplet gap >620 K (430 cm(-1)). The Cu(2+) (S = 1/2) centers are magnetically isolated and yield a narrow EPR line in the X-band at g = 2.01. The ET moieties are EPR silent.