TY - JOUR

T1 - Synthesis and luminescence properties of new metal-organic frameworks based on zinc(II) ions and 2,5-thiophendicarboxylate ligands

AU - Lysova, Anna

AU - Samsonenko, Denis

AU - Dybtsev, Danil

AU - Fedin, Vladimir

N1 - Publisher Copyright: © 2017 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Six new metal-organic frameworks based on 2,5-thiophendicarboxylate (tdc2–) and zinc(II) ions were prepared in different reaction conditions, and their crystal structures were determined by XRD analysis. The compound [Zn(tdc)(dabco)(H2O)]·DMF (1) is based on mononuclear Zn(II) ions connected by tdc2– and dabco linkers into square-grid layered nets. The compound [Zn3(tdc)3(dabco)2] (2) is a rare example of monocoordinated dabco ligands in the metal-organic framework chemistry. Its crystal structure contains trinuclear linear carboxylate building units, connected into a distorted primitive cubic net. Similar trinuclear units were also found in [Zn5(tdc)4(Htdc)2(dabco)2]·4DMF·14H2O (3), although as a part of more complicated pentanuclear motives. The compound [Na2Zn(tdc)2(DMF)2] (4), quantitatively isolated by the addition of NaOH to the mixture of Zn(NO3)2 and H2tdc, is based on 1D chain motives, interconnected by tdc2– linkers into a three-dimensional framework. The compounds [Zn3(tdc)3(DMF)2]·0.8DMF·1.1H2O (5) and [Zn3(tdc)3(DMF)3]·0.8DMF·1.3H2O (6) were prepared in very similar reaction conditions, but with different times of heating, indirectly indicating higher thermodynamic stability of the three-dimensional metal-organic framework 6, compared to the two-dimensional metal-organic framework 5. The crystal structures of both 5 and 6 are based on the same trinuclear linear units as in 2. Luminescence properties of the compounds 4–6 were studied and compared with those for Na2tdc salt. In particular, the luminescence spectra of 4 practically coincide with those for the reference Na2tdc, while 5 and 6 exhibit coherent shifts of peaks to higher energies. Such hypsochromic shifts are likely associated with a different effective charge on the tdc2– anions in Na2tdc and sodium-containing 4, compared to zinc-based 5 and 6.

AB - Six new metal-organic frameworks based on 2,5-thiophendicarboxylate (tdc2–) and zinc(II) ions were prepared in different reaction conditions, and their crystal structures were determined by XRD analysis. The compound [Zn(tdc)(dabco)(H2O)]·DMF (1) is based on mononuclear Zn(II) ions connected by tdc2– and dabco linkers into square-grid layered nets. The compound [Zn3(tdc)3(dabco)2] (2) is a rare example of monocoordinated dabco ligands in the metal-organic framework chemistry. Its crystal structure contains trinuclear linear carboxylate building units, connected into a distorted primitive cubic net. Similar trinuclear units were also found in [Zn5(tdc)4(Htdc)2(dabco)2]·4DMF·14H2O (3), although as a part of more complicated pentanuclear motives. The compound [Na2Zn(tdc)2(DMF)2] (4), quantitatively isolated by the addition of NaOH to the mixture of Zn(NO3)2 and H2tdc, is based on 1D chain motives, interconnected by tdc2– linkers into a three-dimensional framework. The compounds [Zn3(tdc)3(DMF)2]·0.8DMF·1.1H2O (5) and [Zn3(tdc)3(DMF)3]·0.8DMF·1.3H2O (6) were prepared in very similar reaction conditions, but with different times of heating, indirectly indicating higher thermodynamic stability of the three-dimensional metal-organic framework 6, compared to the two-dimensional metal-organic framework 5. The crystal structures of both 5 and 6 are based on the same trinuclear linear units as in 2. Luminescence properties of the compounds 4–6 were studied and compared with those for Na2tdc salt. In particular, the luminescence spectra of 4 practically coincide with those for the reference Na2tdc, while 5 and 6 exhibit coherent shifts of peaks to higher energies. Such hypsochromic shifts are likely associated with a different effective charge on the tdc2– anions in Na2tdc and sodium-containing 4, compared to zinc-based 5 and 6.

KW - 2,5-thiophendicarboxylic acid

KW - Luminescence

KW - Metal-organic frameworks

KW - X-ray diffraction analysis

KW - Zinc(II) complexes

KW - luminescence

KW - zinc(II) complexes

KW - metal-organic frameworks

UR - http://www.scopus.com/inward/record.url?scp=85040531574&partnerID=8YFLogxK

U2 - 10.3390/cryst8010007

DO - 10.3390/cryst8010007

M3 - Article

AN - SCOPUS:85040531574

VL - 8

JO - Crystals

JF - Crystals

SN - 2073-4352

IS - 1

M1 - 7

ER -