Insights into the Electronic Structure of Cu^IIBound to an Imidazole Analogue of Westiellamide

Histaminol and Its Complexes with Copper(II) – Studies in Solid State and Solution

“…The components of g tensors determined from these spectra are listed in Table . They are in agreement with values reported previously for the Cu II complexes with various derivatives of imidazoles , , , …”

Cyclic peptide marine metabolites and CuII

“…For the methylimidazole-based macrocycle H 3 wa im the detailed analysis of the solution structure and electronic properties of the mono-and dicopper(II) complex was extended with pulsed electron nuclear double resonance (ENDOR), hyperfine sublevel correlation resonance (HYSCORE) and magnetic circular dichroism spectroscopy (MCD), combined with a detailed DFT study, involving the careful validation of the theoretical setup (functional and basis set) 59 -the computation of spin Hamiltonian parameters is notoriously difficult. 117 While the analysis of the ENDOR spectra of [Cu II (H 2 wa im )] + confirmed the bonding motif (N het -N amide -N het ), the three nitrogen nuclei are magnetically inequivalent.…”

“…58 The conformational analysis of the metal-free macrocycles revealed that it is not possible for H 4 pat 1 to adopt a similar structure to those of H 4 asc or H 4 patD, as the incorporated dimethyl-imidazole rings introduce severe steric constraints (see also section on the ligand structures). 59 58 Alignment of the two Cu II centers along the magic angles (θ = 54.7°, ϕ = 45.0°) eliminates the dipole-dipole contribution to the anisotropic exchange interaction, producing an "apparent mononuclear EPR spectrum". Addition of more than three equivalents of base leads to the formation of two structurally different hydroxo complexes, one with a terminal hydroxide, [ and the macrocyclic backbone, such that a typical dipoledipole coupled EPR spectrum emerges.…”

“…With H 4 pat 2 a corresponding complex could be trapped, and its structure was unambiguously determined by EPR spectroscopy together with UV-vis-NIR, CD and MS experiments and combined with DFT-based structure optimization. 59 Interestingly, the structure was determined to be strikingly different to that of [Cu 2 (H 2 asc)(1,2-μ-CO 3 )(H 2 O) 2 ] (see above and Fig. 12; note that the carbonate bridge in the H 4 asc system is in the equatorial position for both Cu II centers with a Cu⋯Cu distance of 3.6 Å, in the H 4 pat 2 system the carbonate is bound equatorially to one and axially to the other Cu II center with a Cu⋯Cu distance of 5.1 Å).…”

Is CuII Coordinated to Patellamides inside Prochloron Cells?

“…To enable investigation of the in vitro coordination chemistry and also to provide patellamide derivatives for structure–activity relationship studies, synthetic routes have been developed to produce cyclic pseudo‐peptides, delivering various model peptides as an alternative to biosynthesis and isolation from natural sources (Scheme ) . Detailed investigations on the dinuclear Cu II complexes were carried out in combination with binding affinity measurements, demonstrating that the model ligands exhibit similar affinities to those reported for the natural patellamides …”