Crystal structure, magnetic and heat capacity properties of a new chiral mononuclear iron(II) compound

Abstract

A new chiral mononuclear iron(II) compound, formulated as {[Fe(ACBP)3]·(ClO4)} (1, ACBP = (S,S)-3,3′-(1,2-dimethylpropanedioxy)-2,2′-bipyridine), has been synthesized and structurally characterized. The magnetic study revealed that compound 1 possesses antiferromagnetic exchange interactions between Fe(II) ions through the hydrogen bonds. The low-temperature heat capacity of compound 1 was measured in the temperature range from 1.9 to 300 K using the heat capacity option of a Quantum Design Physical Property Measurement System (PPMS). Additionally, the thermodynamic functions in the experimental temperature range have been derived by fitting the heat capacity data to a series of theoretical and empirical models. The standard molar heat capacity, entropy and enthalpy of compound 1 at 298.15 K and 0.1 MPa have been determined to be $$C_{\text{p,m}}^{\text{o}}$$ = (1036.9 ± 10.4) J mol−1 K−1, $$S_{\text{m}}^{\text{o}}$$ = (1059.6 ± 10.6) J mol−1 K−1 and $$H_{\text{m}}^{\text{o}}$$ = (160.29 ± 1.60) kJ mol−1, respectively.