Reduction of Mn₁₉ Coordination Clusters on a Gold Surface

Abstract

and Mn III ions in the powder sample. Brillouin function fits to the field-dependent magnetization suggest that the total spin ground state in the submonolayer is much lower than S TOT = 83/2 of the pristine molecules. These findings suggest that significant changes of the electronic structure, molecular geometry, and intramolecular exchange coupling take place upon surface deposition. A sample with coverage of 2−3 monolayers shows the presence of Mn III , suggesting that a decoupling layer could stabilize the Mn 19 core on a metallic surface.

{CoII/III5} horseshoe and {NiII4} lacunary cubane coordination clusters: the isobutyrate/N-butyldiethanolamine reaction system

“…12 The facile reactions of the thus-obtained M(ib) 2 powders with H 2 bda in a 1 : 1 ratio in MeCN under reux conditions (Scheme 1) in the presence of air oxygen afforded the dark-green pentanuclear mixed-valent {Co II 3 Co III 2 } complex (1) and the light-green homovalent tetranuclear {Ni II 4 } complex (2), which were isolated in yields of 49% and 22%, respectively. TGA of compound 1 conrms that the solvent-free [Co II 3 Co III 2 (Hbda) 2 (bda) 2 (ib) 6 ] complex retains its integrity up to 140 C against degradation under a nitrogen atmosphere or air ( Fig. S8 and S9 †).…”

“…X-ray magnetic circular dichroism) or scanning probe microscopy experiments, 5 important molecular characteristics for their deposition on a substrate are: low-nuclearity, charge neutrality, moderate solubility and structural stability in organic solvents, thermal stability and sublimability. Furthermore, even paramagnetic coordination clusters with no magnetic anisotropy-induced slow magnetization relaxation or hysteresis (as opposed to SMMs) generate considerable interest if they can be deposited as intact, single molecules, as they can undergo substantial changes in their molecular magnetic anisotropy upon redox processes (see, e.g., reduction of Mn III to Mn II in the mixed-valent {Mn III 12 Mn II 7 } coordination cluster on Au(111) 6 ) at the molecule-surface interface or by external electromagnetic elds.…”

“…We here report a simple reaction system that results in thermally stable, low-nuclearity, charge-neutral coordination clusters [Co II 3 Co III 2 (Hbda) 2 (bda) 2 (ib) 6 ]$2MeCN (1) or [Ni II 4 (Hbda) 3 (ib) 5 (MeCN)] (2) which fall into the archetypal horseshoe-7 and cubane 8 -type structure families, from which numerous chemically 9 and magnetically functionalized derivatives can then be generated. 1 and 2 were obtained under aerobic conditions in the reactions of M(ib) 2 (M ¼ Co and Ni) and N-butyldiethanolamine in acetonitrile (MeCN) and were characterized by elemental analysis, IR spectroscopy, electrospray ionization mass spectrometry (ESI-MS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and single-crystal X-ray diffraction, and by ac and dc susceptibility measurements that were reproduced using CONDON 2.0.…”

Adsorption phenomena of cubane-type tetranuclear Ni(II) complexes with neutral, thioether-functionalized ligands on Au(111)

“…While thiols (-SH) [8], methyl sulfides (-SMe) [9], and 1,2-dithiolanes (-S-S-) [10] have proven to be effective anchoring groups to gold electrodes in the chemistry and physics of magnetic coordination complexes [11], other thioether-like groups such as cyclic thioethers are still unexplored. The systematic investigation of the adsorption phenomena of metal-organic molecules on various metallic surfaces and thus of the generated molecule-substrate hybrids is appealing and worthwhile because it should allow to derive necessary guidelines for the fine-tuning of the critical metal-ligand coordination bonds and the structure and composition of the molecular material.…”

The disclosure of mesoscale behaviour of a 3d-SMM monolayer on Au(111) through a multilevel approach

“…11 However, the conservation or the enhancement at the surface of the properties observed for the non-adsorbed SMM system is still an open issue. Indeed, the SMM-surface interaction can easily lead to the suppression of the target properties if wet approaches are used 12,13 or even to the SMM fragmentation in the case of deposition occurring through sublimation. [14][15][16] Such issues can be very relevant for the kind of SMM of interest in this work ( polynuclear complexes).…”