Interaction of Lead(II) Perchlorate with <i>N</i>′-Isonicotinoylpicolinohydrazonamide and Its Sodium Salt in the Presence of Potassium Cyanide: Yellow Green Light Emitting Phosphors, Stabilized by Tetrel Bonds, and a System to Transform Methanol to Acetate
Ghodrat Mahmoudi, Isabel García‐Santos, Tamara Iglesias-Pereiro, A. Castiñeiras, Julio Corredoira‐Vázquez, Atash V. Gurbanov, Ennio Zangrando, Rosa M. Gomila, Antonio Frontera, Damir A. Safin
Abstract
High Resolution Image Download MS PowerPoint Slide A coordination polymer is synthesized via the reaction of a mixture of Pb(ClO 4 ) 2 and KCN with N′ -isonicotinoylpicolinohydrazonamide ( HL ), leading to the formation and stabilization of a {[Pb 3 L 3 (OAc)(H 2 O)](ClO 4 ) 2 } n · n H 2 O ( 1 · n H 2 O) 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 [Pb 2 L 2 OH](ClO 4 )·H 2 O ( 2 ·H 2 O) with the formation and trapping of the hydroxide anion. In 1 · n H 2 O, 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 · n H 2 O, 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. [Pb 2 L 2 OH] + in 2 ·H 2 O is formed, when a pair of the [PbL] + cations are joined by a hydroxide anion. The Pb···N tetrel bonds bind [Pb 2 L 2 OH] + to form a zigzag-like 1D supramolecular cationic chain. Both complexes are emissive in methanol. The emission profiles of 1 · n H 2 O and 2 ·H 2 O 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 Pb 2+ cation in both structures.