Molecular multifunctionality preservation upon surface deposition for a chiral single-molecule magnet

The synthesis and characterization of a chiral, enneanuclear Mn(III)-based, Single-Molecule Magnet, [Mn9O4(Me-sao)(6)(L)(3)(MeO)(3)(MeOH)(3)]Cl (1; Me-saoH(2) = methylsalicylaldoxime, HL = lipoic acid) is reported. Compound 1 crystallizes in the orthorhombic P2(1)2(1)2(1) space group and consists of a metallic skeleton describing a defect super-tetrahedron missing one vertex. The chirality of the [Mn-9(III)] core originates from the directional bridging of the Me-sao(2-) ligands via the -N-O- oximate moieties, which define a clockwise (1 Delta Delta) or counter-clockwise (1 Lambda Lambda) rotation in both the upper [Mn-3(III)] and lower [Mn-6(III)] subunits. Structural integrity and retention of chirality upon dissolution and upon deposition on (a) gold nanoparticles, 1@AuNPs, (b) transparent Au(111) surfaces, 1 Lambda Lambda@t-Au(111); 1 Delta Delta@ t-Au(111), and (c) epitaxial Au(111) on mica surfaces, 1@e-Au(111), was confirmed by CD and IR spectroscopies, mass spectrometry, TEM, XPS, XAS, and AFM. Magnetic susceptibility and magnetization measurements demonstrate the simultaneous retention of SMM behaviour and optical activity, from the solid state, via dissolution, to the surface deposited species.