Publication Type Journal Article
Title Modulation of coordination in pincer-type isonicotinohydrazone Schiff base ligands by proton transfer
Authors Ghodrat Mahmoudi Ali Akbar Khandar Farhad Akbari Afkhami Barbara Miroslaw A. V. Gurbanov Fedor I. Zubkov Alan Kennedy Antonio Franconetti Antonio Frontera
Year 2019
Month January
Volume 21
Number 1
Pages 108-117
Abstract We present here two different coordination polyhedra of pincer type N2O hydrazone based ligands supplemented with thiocyanate ions. The compounds namely [Hg(SCN)(2)(HL1)] (1) and [Hg(SCN)(2)(HL2)] (2) have a common isonicotinohydrazone fragment and have been prepared by using a coordination driven self-assembly of the Hg(SCN)(2) with two different ligands including 2-benzoylpyridine-isonicotinoylhydrazone (HL1), and 2-acetylpyridine-isonicotinoylhydrazone (HL2). In compound 1 the ligand coordinates to the mercury center in the keto form (?N-NH?C?O) whereas, in compound 2, the proton at the hydrazine group has been shifted to the uncoordinated pyridine ring and the ligand acted as a zwitterion. The structures provide a complementary system for proton transfer within the ligand molecule involving the keto-enol tautomerization of the amide group and 4-pyridyl N protonation. As a result, the relative location of orbitals and ligands in the complexes are different as well as the bonding strength and the coordination polyhedra. We have also studied electrostatically enhanced (either conventional or involving the chelate ring) interactions observed in the solid state of both compounds and analyzed them using DFT calculations, molecular electrostatic potential surface and Bader s theory of atoms in molecules.
Book Title
ISSN 1466-8033
Conference Name
Bibtex ID ISI:000453688500009
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