Hydrogen-Bonded Supramolecular Chain and Sheet Formation by Coordinated Guanidine Derivatives

  • Peter HubbersteyEmail author
  • Unchuleee Suksangpanya
Part of the Structure and Bonding book series (STRUCTURE, volume 111)


The formation of hydrogen-bonded supramolecular 1-D chains and 2-D sheets by planar metal-containing centres co-ordinated by members of the family of hydrogen-bonding ligands, biuret (bu), carbamoylguanidine (cg), biguanide (bg) and their substituted derivatives has been reviewed. Biurets co-ordinate transition metal centres through two carbonyl oxygens, carbamoylguanidines through one imino nitrogen and one carbonyl oxygen and biguanides through two imino nitrogens. Planar cations with the hydrogen-bonding potential to form 1-D chain or 2-D sheet structures are formed by bidentate ligands with square planar metal centres, especially Ni2+ and Cu2+, when the metal:ligand ratio is 1:2 [ML2]n+ and by tetradentate ligands when the metal:ligand ratio is 1:1 [ML]n+. The majority of the literature abstracted for the review reports biguanide-type co-ordination. Only a limited number of authors have considered biuret-type co-ordination and even fewer have investigated carbamoylguanidine-type co-ordination. Where comparable data are available, trends can be discerned and common structural themes and supramolecular synthons identified. Thus [ML2]n+ species containing two bidentate biguanides often use their N-H donors to act as four-connecting cations forming hydrogen-bonded 2-D sheets with (4,4) topologies. Modification of the two-connecting anion-mediator leads to networks of different size and cohesion. Chloride and bromide form relatively small, fragile, frameworks whereas nitrate and tetrafluoroborate form larger, more robust, networks. Similarly [ML]n+ species containing a single tetradentate biguanide often use their N-H donors to form anion mediated 1-D chains. Depending on the relative orientations of the cations, the chains are linked by hydrogen-bonding contacts through anions and/or solvent molecules to form either 1-D ribbons or 2-D sheets. These [ML]n+ cations have also been shown to bind the pyrimidine bases cytosine and thymine in elegant hydrogen-bonded 2-D sheet architectures.

Hydrogen bonding Supramolecular chains Supramolecular sheets Coordination Guanidine 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Authors and Affiliations

  1. 1.School of ChemistryUniversity of NottinghamNottinghamUnited Kingdom

Personalised recommendations