Synthesis and characterization of some novel pentagonal bipyramidal 2,6-diacetylpyridine bis(benzoylhydrazone) (DAPBH2) complexes of Rhenium(III) and molybdenum crystal and molecular structure of [ReCl(DAPB)(PPh3)]. An investigation of the Mössbauer spectroscopy of [FeIICl2(DAPBH2)]·H2O and [FeIIICl(DAP-Me-B)(H2O)]

Synthesis, characterization and antimicrobial activity of pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with 2,6-diacetylpyridine bis(trimethylammoniumacetohydrazone)

“…Conformational flexibility and large number of potential donors of 2,6-diacetylpyridine dihydrazones allow different modes of coordination to metal ions. Most obtained complexes have pentagonal-bipyramidal (PBPY-7) geometry with pentadentate coordination of dihydrazone via pyridine nitrogen, two azomethine nitrogens and two carbonyl oxygens (N 3 O 2 ) while apical positions are occupied by monodentate ligands [4][5][6][7][8][9].…”

“…Depending on the reaction conditions and nature of the metal, 2,6-diacetylpyridine dihydrazones are able to coordinate in neutral (scheme 1a) [4][5][6][7][8][9], mono-(schemes 1b and 1c) [10] and doubledeprotonated forms (scheme 1d) [11]. Lanthanide complexes with coordination numbers larger than seven were reported [12][13][14][15][16][17] with one dihydrazone ligand and the remaining coordination sites occupied with monodentate or bidentate ligands [12][13][14][15][16][17]; however, in isostructural complexes of Pr(III) and Sm(III) two ligands are pentadentate N 3 O 2 coordinated to the metal ion [14].…”

Recent developments in penta-, hexa- and heptadentate Schiff base ligands and their metal complexes

“…s c r i p t one [MoCl2(N3O2-SB)] was briefly reported by Howe and co-workers in 1994[139], and formulated as a seven-coordinate molybdenum(IV) complex containing the doubly deprotonated pentadentate 2,6-diacetylpyridine-bis(4-methylbenzoylhydrazone) ligand (N3O2-SB) in the equatorial plane of the complex. in 2017, Mironov et al[140], prepared a similar heptacoordinated pentagonal bipyramidal Mo(IV) complex 7, expected to be efficient Ising-spin building block for tailoring single-molecule magnets (SMMs)[141][142][143].…”

Chemistry of Re withN,N‘-Bis(2-pyridylmethyl)ethylenediamine (H2pmen): Hydrolysis, Dehydrogenation, and Ternary Complexes

“…Seven-coordinate Re III complexes are common, and notable examples are the monocapped trisdioxime species of formula ReX(dioxime) 3 BR, where R is a variety of organic groups and X is a monodentate anion. 45,46 Tc analogues of these dioxime complexes, BATO, represent a family of successful heart-imaging agents. Except for a long Re-Cl bond, bond…”