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Journal articles
New compounds with bridging dicyanamide and bis-chelating 2,2′-bipyrimidine ligands: Syntheses, structural characterisation and magnetic properties of the two-dimensional materials [Fe2(dca)4(bpym)]·H2O and [Fe2(dca)4(bpym)(H2O)2]
Abstract : The new polymeric, two-dimensional compounds [Fe2(dca)4(bpym)]·H2O (1) and [Fe2(dca)4(bpym)(H2O)2] (2) (dca- = dicyanamide anion and bpym = 2,2′-bipyrimidine) have been synthesised and characterised by infrared spectroscopy and X-ray crystallography. Both compounds consist of two-dimensional networks of octahedrally co-ordinated iron(II) cations, bridged by bis-bidentate 2,2′-bipyrimidine and bridging dicyanamide anions. The metals are in a distorted octahedral environment due to the small bite angle of the bpym ligands [75.3(1)° in 1 and 73.7(1)° in 2]. The main difference between the two structures is the co-ordination mode of the dca ligands. In compound 1, the iron(II) cation is linked by four dca bridging ligands and by one bis-chelating bpym. In compound 2, each iron cation is linked by two trans-bridging dicyanamide ligands, one bis-chelating bpym and two unidentate ligands in a cis arrangement (one terminal dicyanamide and one water molecule). The main consequence of the different dca co-ordination modes is that each metal cation is connected to four neighbouring metals in 1 but to only three in 2. Magnetic measurements reveal a broad maximum in the χm vs. T plots at ca. 11 K for both compounds, which is characteristic of antiferromagnetic exchange interactions between the high-spin iron(II) centres (J = -1.6 cm-1, g = 2.20 for 1 and J = -1.8 cm-1, g = 2.15 for 2).
Keywords :
2
2' bipyrimidine
bridged compound
cyanamide
dicyanamide
iron complex
metal complex
pyrimidine derivative
unclassified drug
water
analytic method
article
chemical binding
comparative study
crystal structure
environment
iron chelation
magnetism
measurement
priority journal
structure analysis
synthesis
https://hal.univ-brest.fr/hal-01770133
Contributor : Nicolas Renard <>
Submitted on : Wednesday, April 18, 2018 - 4:15:47 PM
Last modification on : Thursday, February 7, 2019 - 11:10:05 AM
Contributor : Nicolas Renard <>
Submitted on : Wednesday, April 18, 2018 - 4:15:47 PM
Last modification on : Thursday, February 7, 2019 - 11:10:05 AM
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