Phase transitions and unusual behavior of heat capacity in metal organic framework compound Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}·N{sub 2}(CH{sub 2}){sub 6}
- A.V. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Academician Lavrentiev Avenue, Novosibirsk 630090 (Russian Federation)
Thermodynamic properties of high-porous metal-organic framework (MOF) compound Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}·N{sub 2}(CH{sub 2}){sub 6} were studied in the temperature range 8.9–300 K using low-temperature adiabatic calorymetry and DSC methods. Phase transitions were observed at ∼15, ∼60, and ∼135 K. It is shown that specific heat of the compound obeys the classical Debye law C{sub p}∼T{sup 3} only below 15 K, whereas above 15 K it is proportional to the first degree of temperature, C{sub p}∼T, to indicate a strong anisotropy of crystal vibrations corresponding to 1D continuum. It is shown that the strong anisotropy can be related to coordination interaction of Zn{sup 2+} and N{sub 2}(CH{sub 2}){sub 6} ligands in the specific structure of compound Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}·N{sub 2}(CH{sub 2}){sub 6}. - Graphical abstract: Specific heat C{sub p} is proportional to the first degree of temperature showing a strong anisotropy of crystal vibrations corresponding to 1D continuum in Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}·N{sub 2}(CH{sub 2}){sub 6.} - Highlights: • Specific heat capacity of Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}·N{sub 2}(CH{sub 2}){sub 6} was first studied at 8.9–300 K. • Phase transitions were observed at ∼15, ∼60, and ∼135 K. • The heat capacity is proportional to the first degree of temperature above 15 K. • The discovered dependency corresponds to a one-dimensional vibration continuum.
- OSTI ID:
- 22451140
- Journal Information:
- Journal of Solid State Chemistry, Vol. 220; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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