• Das, Soma
• Ahmadi, Majid
• Ishikawa, Yasuyuki
• Chakraborty, Indranil
• Skachkov, Dmitry
• Baran, Peter
• Raptis, Raphael G.

Abstract

<p>Two water-soluble iron-pyrazolato complexes (compounds 3 and 4), [Fe ₈], have been prepared by introducing twelve hydroxyalkyl groups to the periphery of the approximately spherical octanuclear molecule. They are contrasted with their two organosoluble chloroalkyl analogues (compounds 1 and 2). All four complexes were characterized in solution by ¹H NMR and electrospray ionization mass spectrometry. The one-electron-reduction product of water-soluble 3, [Fe ₈] ^-, was structurally characterized by single-crystal X-ray diffraction analysis. In aqueous media, the four terminal Fe-Cl bonds of [Fe ₈] are partially hydrolyzed, and the resulting chlorido-aqua-hydroxido species form supramolecular nanoscale aggregates, as determined by dynamic light scattering and electron microscopy. Preliminary computational studies with DFT methods were employed to model the H-bonding interactions controlling the competing solvation and aggregation processes. Twelve hydroxyalkyl pendant groups render an octanuclear iron-oxido-pyrazolato complex soluble in water, where partial hydrolysis and extended intermolecular H-bonding interactions result in supramolecular assemblies.</p>

Topics

• compound
• x-ray diffraction
• mass spectrometry
• density functional theory
• electron microscopy
• iron
• Nuclear Magnetic Resonance spectroscopy
• spectrometry
• dynamic light scattering