Elsevier

Polyhedron

Volume 29, Issue 4, 10 March 2010, Pages 1299-1304
Polyhedron

Supramolecular architectures constructed with the skeletons of zinc(II) 2,2′-bipyridine and barbiturate anion: Synthesis and characterization

https://doi.org/10.1016/j.poly.2010.01.010Get rights and content

Abstract

The barbiturate 1,5-dihydro-5-[5-pyrimidine-2,4(1H,3H)-dionyl]-2H-chromeno[2,3-d] pyrimidine-2,4(3H)-dione) (LH4) 1 forms a complex with Zn(bpy)(NO3)2·2H2O (bpy = 2,2′-bipyridine) of composition [Zn(bpy)2(H2O)2]2+·(LH3)2·7H2O (2). In this structure, the ligand exists as anion (LH3-) as revealed by its single crystal X- ray crystallographic study. Packing studies of 2 provide three dimensional helical chains as secondary structure. However, its PXRD pattern shows that 2 does not retain its structure upon dehydration. Recrystallization of 2 from DMSO results in complex 3 with the composition [Zn(bpy)2(H2O)2]2+·(LH3-)2·DMSO·9H2O assigned on the basis of its elemental analysis and its X-ray crystallography. In order to understand the role of the 2,2′-bipyridine ring in the construction of supramolecular architecture, the reaction of zinc(II) nitrate salt with 1 is carried out to provide complex 4 of composition [Zn(LH3)2(H2O)4]·4H2O characterized by its single crystal X-ray diffraction study. Thermal, emission and photoluminescence properties of the complexes are also studied.

Graphical abstract

A barbiturate derivative complexed with Zn(bpy)(NO3)2·2H2O and Zn(NO3)2·H2O provides fluorescent supramolecular architectures which are characterized by their single crystal X-ray crystallographic studies.

  1. Download : Download full-size image

Introduction

Non-covalent interactions between molecular components play important roles in the binding and conformation of various biological molecules as well as in the functioning of enzymes, antibodies, membranes, carriers and channels [1], [2]. The molecular assembly through H-bonding, π–π stacking and CH–π interactions has emerged as an interesting field of crystal engineering [3], [4], [5], [6], [7]. Supramolecular interactions provide a path to understand the packing of coordination polymers in crystal lattice. In this context, nitrogen-containing ligands are prominent in coordination polymers and supramolecular coordination chemistry [8], [9], [10], [11]. However, barbiturate ring systems besides their pharmaceutical importance [12], [13], [14], [15] possess thymine like hydrogen bonding functionalities and are considered good precursor for the construction of H-bonded networks. Additionally, water clusters are found important in crystal engineering in view of several reports on 1D, 2D and 3D water polymers [16], [17], [18], [19], [20]. These water clusters are usually incorporated in the hollow space of the metal–organic framework and provide a path for supramolecular interactions between the metal and the ligand. The presence of water molecules in the structure can play an important role in stabilizing some supramolecular species as the number of hydrogen bond donors and acceptors can differ significantly from those of the anhydrous compounds [21]. Krygowski et al. have already described the role of water as a ‘glueing factor’ in organic crystals because of its readiness to deform from ideal H-bonded geometry [22]. Despite some success, it is still extremely difficult to construct water networks artificially because the structural constraints required in stabilizing these chains are not fully understood. On one hand, there have been a few studies in constructing artificial hosts for water clusters [23], [24], [25]. On the other hand, in recent papers, the role of water clusters in the crystallization process has also been investigated by introducing other solvent molecules such as methanol and DMSO [26]. Zn(bpy)(NO3)2·2H2O was selected as metal precursor and the 2,2′-bipyridine ring as a ligand to facilitate π-interactions. The barbiturate 1 possesses multiple hydrogen donor and acceptor functionalities which could be suitable for H-bonding as exploited by Hamilton and co-workers [27].

The synthesis of Zn(II) bipyridyl barbiturate has been accomplished to study the X-ray single crystal structure and the photo physical and thermal properties.

Section snippets

Materials and methods

Barbituric acid, 2,2′-bipyridine, salicylaldehyde and zinc(II) nitrate dihydrate were purchased from Sigma–Aldrich and were used as received without further purification. All the solvents were purchased from E. Merk and were freshly distilled prior to use. Ligand 1 and Zn(bpy)(NO3)2·2H2O were prepared and characterized using reported procedures [28], [29].

Physical measurements

The IR spectra (KBr disc, 400–4000 cm−1) were recorded on a Varian FTIR 3100 spectrometer; NMR (300 MHz, DMSO, Me4Si) spectra were recorded on

Synthesis and characterization

Compound 1 and Zn(bpy)(NO3)2·2H2O are prepared and characterized using reported procedures [28], [29]. However, compound [Zn(bpy)2(H2O)2]2+·(LH3-)2·7H2O (2) is synthesized by the reaction of LH4 with Zn(bpy)(NO3)2·2H2O in a 1:1 molar ratio in DMF and methanol followed by addition of excess water. Complex 3 is isolated as crystals upon leaving a solution of 2 in DMSO along with an aqueous solution of 4-methylamino-6-oxopyrimidine for one month at room temp [23]. Attempts were made to crystallize

Conclusion

In summary, complex (2) consists of an octahedral Zn(II) cation and a derivative of a barbiturate anion and is synthesized and characterized by its single crystal X-ray study. The assembled structure constitutes an example of channel type organization giving an appearance of helical chains encapsulating several water molecules. 2 incorporates DMSO and stabilizes the resulting architecture through H-bonding interactions from co-crystallized water molecules. However, H-bonding interactions have

Acknowledgements

Financial support from DAE-BRNS (Grant No. 2005/37/33/BRNS/1807 to L. M.), Mumbai, single crystal X-ray data from IITB, Powai, Mumbai, India and Kyushu University, Japan (Professor Teruo Shinmyozu) are gratefully acknowledged.

References (45)

  • A.Y. Robin et al.

    Coord. Chem. Rev.

    (2006)
  • T. Ito et al.

    Life Sci.

    (1996)
  • T.M. Krygowski et al.

    Tetrahedron

    (1998)
  • S. Sen et al.

    Polyhedron

    (1997)
  • H.W. Roesky et al.

    Coord. Chem. Rev.

    (2003)
    C.D. Ene et al.

    J. Am. Chem. Soc.

    (2009)
  • J.M. Lehn

    Supramolecular Chemistry

    (1995)
  • B. Covelo et al.

    CrystEngComm

    (2006)
  • P. Vishweshwar et al.

    Cryst. Growth Des.

    (2006)
  • R. Carballo et al.

    CrystEngComm

    (2005)
  • S. Kitagawa et al.

    Chem. Soc. Rev.

    (2005)
  • J. M Polino et al.

    Chem. Soc. Rev.

    (2005)
  • M.C. Aragoni et al.

    CrystEngComm

    (2005)
  • S. Kitagawa et al.

    Chem. Commun.

    (2006)
  • S. Kitagawa et al.

    Angew. Chem., Int. Ed.

    (2004)
  • Y. Kyogoku et al.

    Nature (London)

    (1968)
  • M.C. Smith et al.

    Drugs

    (1991)
  • I.K. Ho et al.

    Annu. Rev. Pharmacol. Toxicol.

    (1981)
  • B.K. Saha et al.

    Chem. Commun.

    (2006)
  • X. Mei et al.

    CrystEngComm

    (2006)
  • J.P. Naskar et al.

    CrystEngComm

    (2005)
  • B.Q. Ma et al.

    Chem. Commun.

    (2005)
  • Cited by (12)

    • Multifunctional polymer bearing malonylurea groups for the fabrication of coordination complexes and supramolecular assemblies

      2021, European Polymer Journal
      Citation Excerpt :

      The malonylurea and its derivatives were demonstrated to be able to coordinate with various metal ions to form complexes ions, such as AgI [4], AuI [5], CuII [6], CoII [7] and HgII [8]. These metal complexes of malonylurea have gained considerable interest and exhibited potentially useful properties, such as biological activity [9,10],catalytic activity [11],molecular recognition [12,13], photoluminescence [14,15] and nonlinear optical property [16]. For example, each AgI ion can be coordinated by two deprotonated N atoms from two malonylurea ligands in a perfectly linear geometry, which can produce the hetero-ligand coordination polymer.

    • Barbituric acids as a useful tool for the construction of coordination and supramolecular compounds

      2014, Coordination Chemistry Reviews
      Citation Excerpt :

      The medicinal properties of BAs mainly depend on the side groups attached to the pyrimidine ring. Moreover, the organic salts of BAs and their metal complexes possess potentially useful properties, for instance, NLO [127,138,234], solvatochromism [128,234], biological activities [131,184,192], molecular recognition [102,109,110], photoluminescence [135,193,204], catalytic activity [183,184], etc. In supramolecular chemistry, multifunctional BAs are useful building blocks for the preparation of cocrystals, organic/inorganic salts, heteropolynuclear and/or multicomponent architectures.

    • Reversible and pH dependent photophysical properties of mixed-ligand Ru(II) complexes containing 2,2′-bipyridine and nitrosobarbiturate: Experimental and theoretical approach

      2013, Inorganica Chimica Acta
      Citation Excerpt :

      The solvents were purchased from E. Merck and were freshly distilled prior to use. The metal precursor and LH4 were synthesized using reported methods with minor modifications [13,14]. Elemental analysis of the complexes was carried out using a Carbo-Erba 1108 elemental analyzer, IR spectra were recorded as KBr pellets on a JASCO FT-IR 5300 spectrometer and NMR spectra were recorded in DMSO-d6 on a JEOL AL 300 MHz spectrometer using Me4Si as a reference.

    • Iodine catalyzed synthesis of the chromene derivatives in one-pot

      2012, Chinese Chemical Letters
      Citation Excerpt :

      A careful literature survey indicates that limited work on the synthesis of chromene core was reported from salicylaldehyde and dimolecular 1,3-dicarbonyl compounds [11,13,16], especially B1, to the best of our knowledge, have never been reported to synthesize P1 before.

    • One pot synthesis of Cu(II) 2,2′-bipyridyl complexes of 5-hydroxy-hydurilic acid and alloxanic acid: Synthesis, crystal structure, chemical nuclease activity and cytotoxicity

      2011, Journal of Inorganic Biochemistry
      Citation Excerpt :

      This reaction provided complex 3 of type [Cu(LH3)2(H2O)2], which retained the original ligand framework. In view of the aforementioned reports and owing to the biological significance of Cu(II) ions [32], the nuclease property of the novel complexes was studied. In addition, the present article embodies the spectroscopic and single crystal characterization of the newly synthesized complexes.

    View all citing articles on Scopus
    View full text