Organic cations controlling the nuclearity of copper(ii) 2,5-pyridinedicarboxylates

Abstract

Depending on the organo-cation mononuclear or polynuclear copper(II) 2,5-pyridinedicarboxylates (L) are formed. Mononuclear complexes with [ML 2 (H 2 O)] anions are formed when the cations are derived from ethylenediamine (en), N,N,N 0 ,N 0 -tetramethylethylenediamine (tmen), 1,5-diaminopentane (dap) and 1,4diazabicyclo[2.2.2]octane (dabco). The use of 4-amino-benzylamine (4aba) as the cation source leads to the hexa-coordinated mononuclear complex [CuL 2 (H4aba) 2 ]$8H 2 O. The use of 1,8-diaminooctane (dao) results in a trinuclear complex with the [Cu 3 L 6 ] 6À anion. The trinuclear anion has copper ions in a square pyramidal and square planar geometry. The use of diethylenetetramine (deta) led to a coordination polymer which had unique hexa and penta coordinated copper ions. It is comprised of dinuclear copper 2,5-pyridinedicarboxylates bridged by mononuclear [ML 2 ] 2À units through side on contacts between the carbonyls on the dinuclear part. The 8-aminoquinolinium cations act as counter ions of the coordination polymer with [CuL 2 ] 2À repeat units. In this coordination polymer, the cations are p-stacked in one dimension. The variation in coordination numbers and the types of chains in the coordination polymers are described.

Electrocatalytic Water Oxidation by Mononuclear Copper Complexes of Bis-amide Ligands with N4 Donor: Experimental and Theoretical Investigation

“…The spectrum recorded at room temperature shows one broad isotropic EPR signal with the g iso value of 2.05 to 2.08. Hyperfine features due to copper ( s = 1/2, I = 3/2) are not observed due to the tumbling motion of the molecules. − The magnetic susceptibilities of 1.71, 1.83, and 1.80 μ B for the Cu­(II)–amide complexes 1 , 2 , and 3 , respectively, indicate the presence of one unpaired electron, showing the complex to be mononuclear in nature.…”

Effects of N-oxidation on the molecular and crystal structures and properties of isocinchomeronic acid, its metal complexes and their supramolecular architectures: experimental, CSD survey, solution and theoretical approaches

“…These features confer the potential to construct higher-dimensional extended structures. 21,22 The carboxylate groups display various coordination modes including monodentate (terminal and bridging) and bidentate (chelating and bridging). 23 Meanwhile, 5-carboxylate has a stronger bridging capability than 2-carboxylate due to its strong electron-donating and electrostatic power.…”

New Solvatomorph of Tetrakis(Μ2-Acetato-O,O')-Bis(Isonicotinamide-N)-Di-Copper(II): Synthesis, IR, TGA and X-Ray Study

“…In all studies isonicotinamide coordinates to the copper(II) ion in a monodentate form through the pyridine N atom or in a bidentate one [16] thus providing possibilities for polymeric coordination networks. Pyridine-2,5-dicarboxylic acid combines the advantages of both organic multicarboxylic acids and heteroaromatic compounds and displays versatile coordination modes through its one N atom and four carboxylate O atoms, which in alliance with Cu(II) leads to the formation of coordination homometallic [23][24][25][26][27] and/or heterometallic [26,[28][29][30] polymers. With that in mind, in this contribution, we intended to extend the dimensionality of a new coordination compound obtained by the combination of isonicotinamide with pyridine-2,5-dicarboxylate ligands.…”