Synthesis, Crystal Structure, and Catecholase Activity of Three Trinuclear Heterometallic Ni^II₂–Mn^II Complexes Derived from a Salen‐Type Schiff Base Ligand

Abstract

Three new trinuclear heterometallic nickel(II)-manganese(II) complexes, [(NiL) 2 Mn(NCS) 2 ] (1), [(NiL) 2 Mn(NCO) 2 ] (2), and [{NiL(EtOH)} 2 Mn(NO 2 ) 2 ]·2EtOH (3), have been synthesized by using [NiL] as the so-called "ligand complex" [where H 2 L = N,NЈ-bis(salicylidene)-1,3-propanediamine] and have been structurally characterized. Crystal structure analyses revealed that complexes 1 and 2 are angular trinuclear species, in which two terminal four-coordinate square planar [NiL] moieties are coordinated to a central Mn II through double phenoxido bridges. The Mn II is in a six-coordinate distorted octahedral environment that is bonded additionally to two mutually cis nitrogen atoms of terminal thiocyanate (in 1) and cyanate (in 2). In complex 3, in addition to the double phenoxo bridge, the two terminal Ni II ions are linked to the central [a]

Investigation of 3d-transition metal acetates in the oxidation of substituted dioxolene and phenols

“…The structural and functional aspects of CO have been elucidated with the help of several model systems [24,49,68,71,81,82,84,[100][101][102]. In addition the search for the mimics leads to several alternate mechanisms of oxidation [20][21][22]46,[103][104][105].…”

“…The metals were chosen from the list of 3d-metals used so far to design mimics of CO or PHS using different ligand systems viz. copper [24,, iron [25,[55][56][57], cobalt [58][59][60][61][62][63][64][65], manganese [66][67][68][69][70][71][72][73][74][75][76][77][78][79], nickel [26,68,[80][81][82][83] and zinc [33,84]. PHS mimics cannot be found as much as CO but yet are well studied with 3d-metals viz.…”

Synthesis of Schiff Bases from Substitute Aromatic Aldehydes and 2-(4-aminophenyl)acetonitrile Catalysed by 3,5-difluoroarylboronic Acid

“…Then we added phenylboronic acid (0.015 mmol) as the catalyst to improve the reaction, and the desired 4a was obtained in 79% yield (entry 3). Arylboronic acids with electron-donating groups showed higher yields (entries 4 and 5). It is noteworthy that ideal yields were obtained when the reaction was carried out using arylboronic acids with electron-withdrawing groups (entries 6-8).…”

Use of Cu(II)-di-Schiff bases as metalloligands in the formation of complexes with Cu(II), Ni(II) and Zn(II) perchlorate

“…in catalysis [1,2], magnetism [3][4][5][6], electron transport processes [7] and sensing [8]. There are various strategies to synthesize polynuclear complexes; one of them is to use the neutral complex of divalent transition metal ion with salen type N 2 O 2 donor tetradentate di-Schiff base ligands (salen = N,N 0 -ethylenebis(salicylideneimine)).…”