Ligands and polymetallic complexes derived from 1,4-diformyl-2,3-dihydroxybenzene and two close analogues

Chiral tetranuclear and dinuclear copper(ii) complexes for TEMPO-mediated aerobic oxidation of alcohols: are four metal centres better than two?

“…12-17 However, the types of organic ligands exploited in the copper catalyst systems are still limited and the structures of copper catalysts involved in the catalytic process are rarely explored. [17][18][19][20] The construction of metal-organic cluster compounds through self-assembly of predesigned ligands with appropriate metal ions is a prime research topic [21][22][23][24][25] Herein, we report the one-pot syntheses and crystal structures of two tetranuclear and dinuclear copper(II) complexes resulting from the in situ synthesis of chiral Schiff base ligands (Scheme 1), and their catalytic applications in the TEMPO-mediated aerobic oxidation of benzylic alcohols. The catalytic potential of two complexes is compared based on their catalytic performance in various alcohol oxidation reactions, suggesting that the copper(II) complex with a Cu 4 core is a more efficient catalyst than that one having a Cu 2 core.…”

“…[12][13][14][15][16][17] However, the types of organic ligands exploited in the copper catalyst systems are still limited and the structures of copper catalysts involved in the catalytic process are rarely explored. [17][18][19][20] The construction of metal-organic cluster compounds through self-assembly of predesigned ligands with appropriate metal ions is a prime research topic [21][22][23][24][25] due to the advantages in catalysing useful chemical transformations, in contrast to simple monometallic complexes. [26][27][28][29][30] Schiff base type ligands are excellent ligand candidates for high-nuclearity metallosupramolecular assemblies, in particular in cases where additional O-donor atoms have been introduced to the backbone of a Schiff base ligand scaffold.…”

A Non‐sandwiched Macrocyclic Monolanthanide Single‐Molecule Magnet: The Key Role of Axiality

“…Such a system is highly desirable as it should enhance the nuclearity/geometry control, stability, tunability and solubility of the complex, all of which are important factors for potential future applications. Here we present the first example of such a SMM.The organic macrocycle system we selected for this purpose (Scheme 1) was inspired [11] by those reported by Nabeshima and co-workers [12] and MacLachlan and co-workers.[13]Macrocyclic ligands provide discrete, metal ion binding pockets and thus offer far more predictable cluster nuclearity and structure than acyclic analogues can. Here the [3+3] macrocycle provides three N 2 O 2 pockets for 3d metal ions and one central O 6 pocket for a lanthanide ion, so mixedmetal M 3 Ln tetrametallic macrocyclic complexes are a predictable outcome (in comparison, unpredictable aggregates of 4-12 metal ions were obtained with acyclic ligand analogues [14] ).…”

Preparation and Properties of a Series of [Cr2Ln2] Oximato‐Bridged Complexes

“…[1] In particular, oxime ligands can be used to combine lanthanide (Ln) and transition metal ions in one complex molecule. Thus e.g.…”