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Structural Phase Transition without Accompanied Spin Transition of Complex t ‐{Fe(abpt) 2 [N(CN) 2 ] 2 }
Author(s) -
Sheu ChouFu,
Chuang YuChun,
Liu YiHung,
Sheu HwoShuenn,
Wang Yu
Publication year - 2010
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201000108
Subject(s) - triclinic crystal system , chemistry , crystallography , phase transition , octahedron , crystal structure , diffraction , bond length , crystal (programming language) , x ray crystallography , powder diffraction , phase (matter) , condensed matter physics , physics , programming language , organic chemistry , computer science , optics
Abstract A reversible crystal‐to‐crystal structural phase transition is found in one of the polymorphs ( A ) of complex t ‐{Fe(abpt) 2 [N(CN) 2 ] 2 } (abpt = 4 ‐Amino‐3,5‐bis (pyridin‐2‐yl)‐1,2,4‐triazole). The crystal at 25 K remains unchanged as triclinic space group P − 1 from that of the ambient temperature, but with different cell parameters: a = 8.7960(6), b = 8.8110(9), c = 10.1020(7) Å, α = 94.146(8)°, β = 93.296(6)°, γ = 114.460(7)°, V = 707.48(10) Å 3 . Thermal‐dependent powder X ‐ray diffraction reveals a first order phase transition with transition temperature, T 1/2 , at 270 K, which coincides with the change in cell parameters monitored by single crystal diffraction experiment. The molecular structure does vary on the orientation of the axial ligand, N(CN) 2 , during the phase transition, however the Fe‐N bond distance and the octahedron distortion parameters around Fe indicate that Fe remains at high spin state even after the phase transition which is in accord with the observed thermal‐dependent magnetic measurement.