Synthesis, crystal structure and bioactivity of a novel 18-metallacrown-6 [Mn6(H2O)6 (anshz)6]·10DMF

A mixed-type of azametallacrown containing [Mn6(pnhz)6(DMF)4(H2O)2] and [Mn6(pnhz)6(DMF)2(H2O)4] constructed by a flexible pentadentate ligand

“…1, S1) [28,29]. X-ray crystallographic analysis indicates that two azametallacrowns in complex 1 are isostructural to the previously reported manganese-based aza18-MC-6 leaving the coordinated solvent molecules out of account [5,9,10]. The H 3 pnhz bridges the metal ions through N-N group in simultaneous tridentate and bidentate binding modes on both sides of the bridging domain (Scheme 1b).…”

“…Among the MCs, diaza-bridged metallacrowns (azaMCs) have gained ever increasing concern in the field of supramolecular chemistry, self-assembly and host-guest chemistry for their fascinatingly symmetrical multi-nuclear frameworks [5][6][7][8][9][10][11] and their potential applications as secondary building units (SBUs) in the construction of 2-or 3-D metal-organic frameworks (MOFs) through the bridging exo-bidentate ligands [12,13]. The self-assembly of the high-nuclear azaMCs with rigid N-terminal ligands has been intensively and, to some extent, successfully investigated [14][15][16][17][18][19][20][21][22][23][24], while of less interest is the exploration of the highly flexible N-terminal groups in such system, which may adjust various geometric modes to satisfy the requirements of assembly process and lead to interestingly structural topologies.…”

“…Six ethyl groups of the N-propionyl side chains in I are alternatively directed into two faces of the metal ring, as shown in most of azametallacrowns (Fig. S3b) [5][6][7][8][9][10][12][13][14][15][16][17][18]. However, only four N-terminal groups in II are directed symmetrically outside the ring, while two symmetry-related N-ends are directed to the inner core of the ring (Fig.…”

An iron(III) 18-metallacrown-6 complex: synthesis, crystal structure, and bioactivity

“…At present, metallacrowns with Mn(III), Fe(III), Ni(II), Cu(II), Zn(II), Ga(III), and V(V)O metal ions, [1], [2], [3], [4], [5], [6,7], secondary ligand. In the complex of metallacrown containing [M-N-N] repeat units, each metal was coordinated with two main ligands and one secondary ligand, forming a distorted octahedral geometry [3][4][5][6][7][8]. The studies showed that the secondary ligand can be changed via adjustment of solvent, while the chelate ring kept the structure without change [12,13].…”

Synthesis, crystal structure and magnetic property of an iron(III) coordination polymer with N-acyl-salicylhydrazide ligand

“…In this context, metallacrowns with [M-N-N] n cyclic repeating units, known as metalladiazamacrocycles, are an important class of metallamacrocycles and have been intensively studied since the first report of a hexanuclear manganese metalladiazamacrocycle in 1998 [4][5][6]. This class of metallamacrocycle is typically prepared by using trianionic pentadentate N-acyl-salicylhydrazide or its analogues as ligand and trivalent octahedral metal ion such as Mn(III), Fe(III), Co(III) and Ga (III) as centre ion [7][8][9][10][11][12][13][14][15][16][17][18][19]. It has been found that the nature of N-acyl groups of the N-acyl-salicylhydrazide ligand can influence the size and nuclearity of the metallamacrocycle formed.…”