Copper(II) and zinc(II) complexes bridged by benzenoid aromatic oxocarbon and dicarboxylate dianions

Franz A. Mautner*, Roland C. Fischer, Ana Torvisco, Emeralde P. Grant, Destiny S.St Romain, Nahed M.H. Salem, Febee R. Louka, Salah S. Massoud

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A novel series of Cu(II) and Zn(II) complexes were constructed through the bridging croconate (C5O5)2−, squarate (C4O4)2− and 2,5-pyridine-dicarboxylate (Py2,5-dc)2− dianions. These include pent- [Cu5(epdmpy)4(C5O5)2(H2O)6](ClO4)6‧12H2O (1) and tri-nuclear [Cu3(bepza)2(Py2,5-dc)2(ClO4)2(H2O)2]‧2H2O (4), dinuclear [Zn2(MeDPA)2(C4O4)(H2O)4](ClO4)2 (7), and 1-D- coordination polymers (CPs) catena-{[Cu2(bpzpy)2(C5O5)](ClO4)2‧MeOH} (2) and catena-{[Zn(4,4′-bipy)(H2O)4](C5O5)(H2O)} (6) as well as the mononuclear [Cu(HBph2,2′-dc)(pmdien)]ClO4 (5) have been synthesized and spectroscopically characterized as well as by single crystal X-ray crystallography. The reaction of aqueous solution Cu(ClO4)2, pymeea and C5O52− resulted in the unprecedently bis(oxalato) [Cu2(Pymeea)2(C2O4)(ClO4)2(H2O)2] (3). In these complexes, (C5O5)2−, squarate (C4O4)2− and (Py2,5-dc)2− ligands display a variety of coordination bonding modes. In complexes 1 and 2 the croconato is binding as 1,2-bidentate-3-monodentate but in addition 5-mono-dentate semi-coordinate bonding was detected for 2, whereas in 6 as counter dianion. The bonding mode in the squarato 7 was achieved through the trans μ1,3-mono-dentate. In the di-carboxylato compounds, only five-membered chelate ring was formed in 5 via one of the carboxylate groups, whereas in 4 bridging was conducted through a mono-carboxylate and five-membered chelate ring including the second carboxylate and pyridyl nitrogen. In complexes 1–5 and 7, hydrogen bonds of type O–H⋯O and/or N–H⋯O are connecting the complex cations with the perchlorate anions/ligands to generate different dimensional supramolecular network structures, whereas in 6, the 3D network was formed through hydrogen bonding between the coordinated aqua and lattice water molecules. Non-covalent ring⋯ring interactions were also observed between pyridyl rings in complexes 1, 6 and 7, and between pyrazolyl rings as well as pyridyl ring in 2.

Original languageEnglish
Article number116327
JournalPolyhedron
Volume234
DOIs
Publication statusPublished - 1 Apr 2023

Keywords

  • Carboxylates
  • Coordination polymer
  • Croconates
  • Crystal structures
  • Polynuclear complexes
  • Squarates

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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