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چکیده
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A coordination polymer is synthesized via the reaction of a mixture of Pb(ClO4)2 and KCN with N′-isonicotinoylpicolinohydrazonamide (HL), leading to the formation and stabilization of a {[Pb3L3(OAc)(H2O)](ClO4)2}n·nH2O (1·nH2O) network, with the formation and trapping of the acetate anion. Using the sodium N-(amino(pyridin-2-yl)methylene)isonicotinohydrazonate (NaL) instead of HL yields complex [Pb2L2OH](ClO4)·H2O (2·H2O) with the formation and trapping of the hydroxide anion. In 1·nH2O, an almost linear aggregate is produced when the 4-pyridine fragments of the two [PbL]+ are coordinated to the metal cation of the third species, joining the three [PbL]+ cations. In 1·nH2O, supramolecular stability is enhanced by Pb···O and Pb···π interactions involving the electron-rich core (Cg) of a ten-membered hydrogen-bonded ring, indicative of tetrel-type bonding. [Pb2L2OH]+ in 2·H2O is formed, when a pair of the [PbL]+ cations are joined by a hydroxide anion. The Pb···N tetrel bonds bind [Pb2L2OH]+ to form a zigzag-like 1D supramolecular cationic chain. Both complexes are emissive in methanol. The emission profiles of 1·nH2O and 2·H2O in MeOH correspond to CIE-1931 chromaticity coordinates of (0.406, 0.492) and (0.420, 0.498), placing them within the yellow-green region of the visible spectrum. DFT studies are applied to reveal noncovalent interactions, including tetrel bonding, governing the supramolecular architectures. Electrostatic potential and QTAIM analyses confirm the presence of σ-holes at the Pb2+ cation in both structures.
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