Isoskeletal Schiff base polynuclear coordination clusters: synthetic and theoretical aspects

Abstract

This work addresses and enlightens synthetic aspects derived from our effort to systematically construct isoskeletal tetranuclear coordination clusters (CCs) of the general formula [TR2Ln2(LX)4(NO3)2(solv)2] possessing a specific defected dicubane topology.

Synthesis, Characterization, Magnetic Properties, and Topological Aspects of Isoskeletal Heterometallic Hexanuclear CoII4LnIII2 Coordination Clusters Possessing 2,3,4M6–1 Topology

“…A combination of single‐crystal and powder X‐ray studies (Figure S1, see Experimental Section) show that compounds 1 – 4 are isoskeletal, hence only the structure of 2 will be described. Three Et 2 O molecules, could be successfully refined in the lattice of 2 and 3 .…”

“…Synthetic Part: Ligands H 2 L1 and H 2 L2 were synthesized according to the literature . Compounds 1 – 4 were synthesized using the same method, therefore only the synthesis of 1 is described here.…”

“…With all of this in mind, we decided to treat H 2 L1 with Co(NO 3 ) 2 6H 2 O and LnCl 3 x (H 2 O), which resulted in a family of hexanuclear heterometallic CCs formulated as [Co II 4 Ln III 2 (µ 3 ‐OH) 2 (L1) 4 Cl 2 (NO 3 ) 2 (MeOH) 4 ] 3(Et 2 O), where Ln is Y ( 1 ), Gd ( 2 ), Dy ( 3 ), and Tb ( 4 ), in very good yields. For structural purposes, the employment of ( E )‐2‐(5‐bromo‐2‐hydroxy‐3‐methoxybenzylideneamino)phenol (H 2 L2, Scheme ) under similar reaction conditions afforded an isoskeletal compound formulated as [Co II 4 Dy III 2 (µ 3 ‐OH) 2 (L2) 4 Cl 2 (NO 3 ) 2 ‐(MeOH) 4 ] ( 5 ). Topological aspects and magnetic properties of these compounds are further discussed.…”

Isolation and Characterization of Different Homometallic and Heterobimetallic Complexes of Nickel and Zinc Ions by Controlling Molar Ratios and Solvents

“…Observations reveal that it is difficult to predict the nuclearity and topology of polynuclear complexes as their formation is controlled by many factors such as molar ratios, nature of solvent(coordinating or non‐coordinating and polarity), counter ion, temperature and stirring time. Therefore, variation in these factors most probably results into change in nuclearity and topology of the cores of those complexes . Herein, by varying aforementioned factors, we report synthesis and characterization of three homometallic Zn II coordination complexes and two heterobimetallic Zn II –Ni II polynuclear complexes with different interesting nuclearities and topologies.…”

Highly Efficient Tetranuclear ZnII2LnIII2 Catalysts for the Friedel–Crafts Alkylation of Indoles and Nitrostyrenes

“…We recently initiated a project on the synthesis of 3d/4f CCs stabilized by the Schiff base organic ligand H2L [(E)-(2-hydroxy-3-methoxybenzylidene-amino)phenol], that would display catalytic properties [57][58][59]. We also reported the synthesis and characterisation of a series of isoskeletal [60] tetranuclear Zn II 2Ln III 2 CCs formulated as [Zn II 2Ln III 2L4(NO3)2(DMF)2] (1Ln) where Ln is Y (1Y), Sm (1Sm), Eu (1Eu) Gd (1Gd), Dy (1Dy), Tb (1Tb) and Yb (1Yb) possessing a defect dicubane topology (Figure 1). These compounds can be synthesized quantitatively in two steps, up to multigram scale and are air stable for a few months.…”