Next Article in Journal
A Hyper-Viscoelastic Constitutive Model for Polyurea under Uniaxial Compressive Loading
Next Article in Special Issue
Single-Crystal-to-Single-Crystal Anion Exchange in a Gadolinium MOF: Incorporation of POMs and [AuCl4]
Previous Article in Journal
Precision Synthesis of Functional Polysaccharide Materials by Phosphorylase-Catalyzed Enzymatic Reactions
Previous Article in Special Issue
A Heterobimetallic Anionic 3,6-Connected 2D Coordination Polymer Based on Nitranilate as Ligand
Article Menu

Export Article

Open AccessArticle
Polymers 2016, 8(4), 137;

Hg(II) Coordination Polymers Based on N,N’-bis(pyridine-4-yl)formamidine

Department of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan, R. O. C.
Author to whom correspondence should be addressed.
Academic Editors: Félix Zamora, Thomas Junkers and Frank Wiesbrock
Received: 25 January 2016 / Revised: 29 March 2016 / Accepted: 1 April 2016 / Published: 11 April 2016
(This article belongs to the Special Issue Coordination Polymers: New Materials for Multiple Applications)
Full-Text   |   PDF [3905 KB, uploaded 11 April 2016]   |  


Reactions of N,N’-bis(pyridine-4-yl)formamidine (4-Hpyf) with HgX2 (X = Cl, Br, and I) afforded the formamidinate complex {[Hg(4-pyf)2]·(THF)}n, 1, and the formamidine complexes {[HgX2(4-Hpyf)]·(MeCN)}n (X = Br, 2; I, 3), which have been structurally characterized by X-ray crystallography. Complex 1 is a 2D layer with the {44·62}-sql topology and complexes 2 and 3 are helical chains. While the helical chains of 2 are linked through N–H···Br hydrogen bonds, those of 3 are linked through self-complementary double N–H···N hydrogen bonds, resulting in 2D supramolecular structures. The 4-pyf- ligands of 1 coordinate to the Hg(II) ions through one pyridyl and one adjacent amine nitrogen atoms and the 4-Hpyf ligands of 2 and 3 coordinate to the Hg(II) ions through two pyridyl nitrogen atoms, resulting in new bidentate binding modes. Complexes 1–3 provide a unique opportunity to envisage the effect of the halide anions of the starting Hg(II) salts on folding and unfolding the Hg(II) coordination polymers. Density function theory (DFT) calculation indicates that the emission of 1 is due to intraligand π→π * charge transfer between two different 4-pyf- ligands, whereas those of 2 and 3 can be ascribed to the charge transfer from non-bonding p-type orbitals of the halide anions to π * orbitals of the 4-pyf- ligands (n→π *). The gas sorption properties of the desolvated product of 1 are compared with the Cu analogues to show that the nature of the counteranion and the solvent-accessible volume are important in determining their adsorption capability. View Full-Text
Keywords: coordination polymer; mercury; formamidine coordination polymer; mercury; formamidine

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Hsu, W.; Yang, X.-K.; Chhetri, P.M.; Chen, J.-D. Hg(II) Coordination Polymers Based on N,N’-bis(pyridine-4-yl)formamidine. Polymers 2016, 8, 137.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top