Abstract
The self-assembly reaction between NiI2, benzoic acid (PhCO2H) and the Schiff base chelate, N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in the presence of the organic base triethylamine (NEt3), has resulted in the isolation and the structural, spectroscopic, and physicochemical characterization of the dodecanuclear [Ni12I2(OH)6(O2CPh)5(nacb)5(H2O)4(MeCN)4]I (1) cluster compound in ~30% yield. Complex 1 has a cage-like conformation, comprising twelve distorted, octahedral NiII ions that are bridged by five μ3-OH−, one μ-OH−, an I− in 55% occupancy, five PhCO2− groups (under the η1:η1:μ, η1:η2:μ3 and η2:η2:μ4 modes), and the naphthoxido and carboxylato O-atoms of five doubly deprotonated nacb2− groups. The overall {Ni12} cluster exhibits a nanosized structure with a diameter of ~2.5 nm and its metallic core can be conveniently described as a series of nine edge- or vertex-sharing {Ni3} triangular subunits. Complex 1 is the highest nuclearity coordination compound bearing the nacbH2 chelate, and a rare example of polynuclear NiII complex containing coordinating I− ions. Direct current (DC) magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions between the NiII ions, while photophysical studies of 1 in the solid-state showed a cyan-to-green centered emission at 520 nm, upon maximum excitation at 380 nm. The reported results demonstrate the rich coordination chemistry of the deprotonated nacb2− chelate in the presence of NiII metal ions, and the ability of this ligand to adopt a variety of different bridging modes, thus fostering the formation of high-nuclearity molecules with rare, nanosized dimensions and interesting physical (i.e., magnetic and optical) properties.
Highlights
Polynuclear 3d-metal complexes remain one of the most attractive research fields in the cross-disciplinary areas of chemistry, physics, and materials science [1]
{Ni6 }) were isolated and structurally characterized [14]. These results have demonstrated the unpredictability of the nacbH2 chelate toward the coordination with 3d-metal ions in solution and subsequently the stabilization of different cluster compounds in the solid-state
We have decided to introduce to the NiII /nacbH2 system anions with very limited coordinating capacity, such as iodides (I− ), in conjunction with organic anionic groups with a superior bridging ability, such as benzoates (PhCO2 − ), in an attempt to harness a flexible ”synthetic blend” which would potentially lead to high-nuclearity NiII clusters
Summary
Polynuclear 3d-metal complexes (or 3d-metal clusters) remain one of the most attractive research fields in the cross-disciplinary areas of chemistry, physics, and materials science [1]. This is mainly due to the ability of these nanosized molecular species to exhibit very interesting magnetic, optical, biological, and catalytic properties, to name just a few [2]. SMMs exhibit slow magnetization relaxation over and/or through an anisotropy barrier and they biological, and catalytic properties, approach to name just few [2]. Theapplications motifs represent a molecular or “bottom-up”
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
