Roles of a unique apical salicylate ligand of neutral [Cu(phen) (Hsal)2(H2O)] to coordination mode, geometry, weak interactions, thermal analysis and spectroscopy

N,N-Alkylation Clarifies the Role of N- and O-Protonated Intermediates in Cyclen-Based 64Cu Radiopharmaceuticals

“…Cu II (DO3A C4H8 ) exists as single species over the pH range of 3–7 and displays an axial spectrum ( g e < g x ∼ g y < g z ) that is consistent with the axially elongated, distorted octahedral geometry and N 3 O 3 binding mode found in the solid state ( g ⊥ : g x = g y = 2.056 G; g ∥ : g z = 2.272 G, A x = A y = 19 × 10 –4 cm –1 ; A z = 176 × 10 –4 cm –1 ). − Both g z and g x , g y compare favorably to axially elongated, distorted octahedral N 4 O 2 species, Cu II (TEBIDA)­(bpy)­(OH 2 ) (TEBIDA: N -tert-butyliminodiaceticacid; g ⊥ : g x = g y = 2.05 G; g ∥ : g z = 2.29 G; Cu–N eq(avg) = 2.013(5) Å, Cu–O eq(avg) = 1.962(5) Å, Cu–N ax = 2.483(6) Å, Cu–O ax = 2.512(5) Å; and O ax –Cu–N ax = 153.2°) . This provides further support that the distorted octahedral geometry observed in the solid state is maintained in solution.…”

Poly(allylamine)-copper(ii) coordination complex grafted on core@shell upconversion nanoparticles for ultrafast and sensitive determination of the phytohormone salicylic acid in plant extracts

“…Moreover, since the SA is a diprotic organic molecule with ionizable carboxylic and phenolic groups, the SA-Cu( ii ) complexes can adopt multiple coordination forms with one or more SA ligands according to the pH and ligand concentration, and different species can coexist in solution. 32 In Fig. 1 is depicted a representative mononuclear complex of Cu 2+ coordinated with two bidentate SA ligands [Cu(SA) 2 2− ], which has been suggested as one of the strongest SA-Cu( ii ) complexes, and together with the [Cu(OH)(SA) 2 3− ] complex as the predominant forms under the analytical conditions of the present work.…”

“…Moreover, since the SA is a diprotic organic molecule with ionizable carboxylic and phenolic groups, the SA-Cu(II) complexes can adopt multiple coordination forms with one or more SA ligands according to the pH and ligand concentration, and different species can coexist in solution. 32 In Fig. 1 ] complex as the predominant forms under the analytical conditions of the present work.…”