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Azido-Cyanide Mixed-Bridged Fe III -Ni II Complexes.

Authors :: Yang J
Zhao XH
Deng YF
Zhang XY
Chang XY
Zheng Z
Zhang YZ
Source :: Inorganic chemistry [Inorg Chem] 2020 Nov 16; Vol. 59 (22), pp. 16215-16224. Date of Electronic Publication: 2020 Oct 26.
Publication Year :: 2020
Abstract: The successful introduction of azide ions as secondary bridges into the Fe <superscript>III</superscript> -Ni <superscript>II</superscript> cyanide system afforded two clusters and one unique 4(3),2-ribbon chain: [(bpzpy) <subscript>2</subscript> Ni <subscript>2</subscript> (μ <subscript>2</subscript> -1,1-N <subscript>3</subscript> ) <subscript>2</subscript> {(pzTp)Fe(CN) <subscript>3</subscript> } <subscript>2</subscript> ]·3H <subscript>2</subscript> O [ 1 ; bpzpy = 2,6-bis(pyrazol-1-yl)pyridine, and pzTp = tetrakis(pyrazolyl)borate], [(L1) <subscript>2</subscript> Ni <subscript>4</subscript> (μ <subscript>3</subscript> -1,1,1-OCH <subscript>3</subscript> ) <subscript>2</subscript> (μ <subscript>2</subscript> -1,1-N <subscript>3</subscript> ) <subscript>2</subscript> (H <subscript>2</subscript> O) <subscript>2</subscript> {(Tp)Fe(CN) <subscript>3</subscript> } <subscript>2</subscript> ]·2CH <subscript>3</subscript> OH·H <subscript>2</subscript> O [ 2 ; Tp = hydrotris(pyrazolyl)borate, and HL1 = 2,6-bis{(2-hydroxypropylimino)methyl}-4-methylphenol], and [(L2) <subscript>2</subscript> Ni <subscript>3</subscript> (μ <subscript>2</subscript> -1,1-N <subscript>3</subscript> ) <subscript>4</subscript> {(pzTp)Fe(CN) <subscript>3</subscript> } <subscript>2</subscript> ] <subscript>n</subscript> ( 3 ; L2 = 2-{[phenyl(pyridin-2-yl)methylene]amino}ethan-1-amine). Both 1 and 2 feature the centrosymmetric {Fe <superscript>III</superscript> -Ni <superscript>II</superscript> <subscript>2</subscript> -Fe <superscript>III</superscript> } and {Fe <superscript>III</superscript> -Ni <superscript>II</superscript> <subscript>4</subscript> -Fe <superscript>III</superscript> } rodlike structures in which the two peripheral [(Tp <superscript>R</superscript> )Fe(CN) <subscript>3</subscript> ] <superscript>-</superscript> anions act as monodentate ligands via one cyanide group to link the central azide-bridged [Ni <subscript>2</subscript> ] and [Ni <subscript>4</subscript> ] subunit, respectively, while 3 displays an extended structure of the double-zigzag (4,2-ribbon) chain in which the double end-on azide-bridged trinuclear [Ni <subscript>3</subscript> ] subunits serve as the 4-connected nodes. Magnetic study revealed that intramolecular ferromagnetic coupling is dominated by the azide or cyanide bridges in all of the complexes. Remarkably, complex 1 behaves as a single-molecule magnet with an effective energy barrier of 16.5 cm <superscript>-1</superscript> at zero dc field, while complex 3 exhibits metamagnetism with a hidden spin canting property below 12 K.