0000000000215347
AUTHOR
Ally Aukauloo
Sheets of alternating chirality in the structure of a novel iron(III) complex with a cyclic oxamide ligand
An organic–metalloorganic analogue of the inorganic clay minerals has been obtained from the cyclization of N,N′-bis(ethoxalyl)phenylenediamine in basic medium in the presence of iron(III) ions leading to formation of a cyclic oxamide ligand (L). The combination of intramolecular (covalent) interactions between metal and ligand and intermolecular (noncovalent) ionic interactions creates a novel layered compound with an intriguing crystal structure (shown on the right).
Manganese(iv) oxamato-catalyzed oxidation of secondary alcohols to ketones by dioxygen and pivalaldehyde
A new manganese(IV) oxamato complex possessing a bis(moxo) dimanganese core has been synthesized, magnetically and structurally characterized, and found to catalyze the aerobic oxidation of secondary alcohols to ketones with cooxidation of pivalaldehyde to pivalic acid with good yields and high selectivities. Ruiz Garcia, Rafael, Rafael.Ruiz@uv.es ; Fernandez Picot, Isabel, Isabel.Fernandez@uv.es ; Pedro Llinares, Jose Ramon, Jose.R.Pedro@uv.es ; Rosello Arce, Antonio Luis, Antonio.L.Rosello@uv.es ; Castro Bleda, Isabel, Isabel.Castro@uv.es
Synyhesis, structure, spectroscopy and redox chemistry of square-planar nickel(II) complexes with tetradentate o-phenylenedioxamidates and related ligands
[EN] A series of four-coordinate square-planar nickel(II) complexes of o-phenylenebis(N¿-methyloxamidate) (L1) and related o-phenylene(N¿-methyloxamidate)oxamate (L2) and o-phenylenebis(oxamate) (L3) tetradentate ligands have been synthesized and characterized structurally, spectroscopically and electrochemically. The parent nickel(II)¿L1 complex presents an intense MLCT band in the UV region (¿max = 357 nm) and a distinctive 1 s ¿ 4p CT satellite in the Ni K-edge XANES spectrum (E = 8339.2 eV). These features together with the short Ni¿N(amidate) bond lengths (1.85¿1.93 Å) as revealed by the analysis of the Ni K-edge EXAFS spectrum and confirmed by single-crystal X-ray diffraction are typi…
Iron(iii) oxamato-catalyzed epoxidation of alkenes by dioxygen and pivalaldehyde
A new iron(III)–carbonato monomeric complex of orthophenylenebis( oxamato) (opba) 1 is synthesized, and spectroscopically and structurally characterized; it is a moderately efficient non-heme catalyst for the aerobic epoxidation of alkenes with co-oxidation of pivalaldehyde. Ruiz Garcia, Rafael, Rafael.Ruiz@uv.es ; Fernandez Picot, Isabel, Isabel.Fernandez@uv.es ; Pedro Llinares, Jose Ramon, Jose.R.Pedro@uv.es
Ein neuartiger Eisen(III)-Komplex mit einem cyclischen Amidliganden und einer Struktur aus Schichten alternierender Chiralität
Ein organisch-metallorganisches Analogon von Tonmineralien wurde unter Cyclisierung von N,N′-Bis(ethoxalyl)phenylendiamin zu einem zweizahnigen Oxamid-Liganden (L) in basischem Medium und in Gegenwart von Eisen(III)-Ionen erhalten. Das Zusammenwirken von intramolekularen (kovalenten) Wechselwirkungen zwischen Metall und Ligand und intermolekularen (nichtkovalenten) ionischen Wechselwirkungen fuhrt dabei zu einer neuartigen Schichtverbindung mit einer faszinierenden Kristallstruktur (siehe rechts).
An Na8 Cluster in the Structure of a Novel oxamato-bridged Na'Cu'' three-Dimensional Coordination Polymer
[EN] The new heterometallic sodium(I)¿copper(II) compound Na4Cu2 (2) · 10.5 H2O (3), where H8[2] stands for N,N',N'',N'''-methanetetrayltetrakismethylenetetrakis(oxamic acid), has been synthesized and its crystal structure determined by single-crystal X-ray diffraction. The structure of 3 consists of cationic [Cu2(¿4:¿4-2)]4- dinuclear units, coordinated sodium cations, and water molecules. In the crystal, the dinuclear copper entities are joined through discrete aggregates of eight sodium atoms linked by oxamato and water bridges, leading to a three-dimensional polymeric network.
Tuning up the Tc in Mn(II)Cu(II) bimetallic planes and design of molecular-based magnets
Abstract A family of related compounds of general formula (PPh4)2Mn2[Cu((L)]3nH2O, where PPh4+ is the tetraphenylphosphonium cation and L stands for ortho-phenylenebis(oxamate) (opba, 1), ortho-phenylene (N′-methyloxamidate) (oxamate) (Meopba, 2) and ortho-phenylenebis (N′-methyloxamidate) (Me2opba, 3), have been synthesized. The X-ray absorption near-edge structure (XANES) and extended X-ray Within absorption fine structure (EXAFS) spectra at both Mn and Cu K-edges for all three compounds, as well as their powder X-ray patterns, are consistent with a layered structure built up of parallel Mn11Cu11 two-dimensional honeycomb networks separated by PPh4+ cations. Within the antonic metallic la…
A Square-Planar Dinickel(II) Complex with a Noninnocent Dinucleating Oxamate Ligand: Evidence for a Ligand Radical Species
[EN] The new bimetallic nickel(II) compound (PPh4)4[Ni2(2)]·6H2O (3), where H8[2] stands for N,N',N'',N'''-1,2,4,5-benzene-tetrayltetrakis(oxamic acid), has been synthesized and its crystal structure determined by single-crystal X-ray diffraction. The structure of 3 consists of [Ni2(n4:n4-2)]4- anions, tetraphenylphosphonium cations, and water molecules. Facile one-electron oxidation of the square-planar diamagnetic dinickel(II) complex [Ni2(n4:n4-2)]4- generates the metallo-radical species [Ni2(n4:n4-2·+)]3- with characteristic intra-ligand ¿cation radical transitions in the visible region (475-550 nm) as well as a typical quasi-isotropic EPR signal at g ¿ 2.0.
Molecular and electronic structure of square-planar nickel(ii), nickel(iii) and nickel(iii)π-cation radical complexes with a tetradentate o-phenylenedioxamidate redox-active ligand
The molecular and electronic structures of the electron transfer series of four-coordinate square-planar nickel complexes with the ligand o-phenylenebis(N'-methyloxamidate), [NiL]z (z = 2-, 1-, 0), have been evaluated by DFT and TDDFT calculations, and most of their experimentally available structural and spectroscopic properties (X. Ottenwaelder et al., Dalton Trans., 2005, DOI: 10.1039/b502478a) have been reasonably reproduced at the B3LYP level of theory. The anionic species [NiL]2- and [NiL]- are genuine low-spin nickel II and nickel III complexes with diamagnetic singlet (S = 0) and paramagnetic doublet (S = 1/2) states, respectively. The nickel III complex presents shorter Ni-N(amidat…