The controlling synthesis of novel nanoclusters of noble metals (Au, Ag) and the determination of their atomically precise structures provide opportunities for investigating their specific properties and applications. Here we report a novel silver nanocluster [Ag307Cl62(SPh t Bu)110] (Ag307) whose structure is determined by X-ray single crystal diffraction. The structure analysis shows that nanocluster Ag307 contains a Ag167 core, a surface shell of [Ag140Cl2S110], and a Cl60 intermediate layer located between Ag167 and [Ag140Cl2S110]. It is a first example that such many chlorides are intercalated into a Ag nanocluster. Chlorides are released in situ from solvent CHCl3. Nanocluster Ag307 exhibits superstability. Differential pulse voltammetry experiment reveals that Ag307 has continuous charging/discharging behavior with a capacitance value of 1.39 aF, while the Ag307 has a surface plasmonic feature. These characteristics show that Ag307 is of metallic behavior. However, its electron paramagnetic resonance (EPR) spectra display a spin magnetic behavior which could be originated from the unpassivated dangling bonds of surface atoms. The direct capture of EPR signals can be attributed to the Cl– intercalating layer which partly suppresses the electronic interactions between core and surface atoms, resulting in the relatively independent electronic states for core and surface atoms.

A first and stable Ag-P superatom nanocluster [Ag(N-triphos)(Cl)](NO) (1) has been successfully synthesized and characterized. X-ray analysis shows that this Ag cluster has a hexacapped body-centered cubic (bcc) framework which is consolidated by four tripodal N-triphos ligands. The identity of 1 is confirmed by high resolution ESI-MS. Cluster 1 has an electronic and geometric shell closure structure with 8 free electrons, matching the stability idea of superatom theory for a nanocluster. DFT calculation of this Ag cluster reveals the superatom feature with a 1S1P configuration. The chelation of multidentate phosphines enhances the stability of this Ag cluster. The AgAg distances between the centered and the vertical Ag atoms of this bcc (Ag@Ag) are in the range of 2.57-2.71 Å, and the distances between the face-capped and the vertical silver atoms are in the range of 2.84-2.92 Å, showing strong AgAg interactions within this cluster core. This superatom complex exhibits a relatively high thermal and photolytic stability.

Eight novel coordination polymers were prepared b y a t r i p o d a l e t h e r -l i n k e d t r i c a r b o x y l i c a c i d : [Mn 3 (TCMB) ,5-tris(carboxymethoxy)benzene, 4-abpt = 4amino-3,5-bis(4-pyridyl)-1,2,4-triazole, Hpdta = 4-(1H-tetrazol-5yl)pyridine, and bpee = 1,2-bis(4-pyridyl)ethene). These complexes were characterized by EA, IR, TGA, PXRD, and single crystal XRD. H 3 TCMB is fully deprotonated, and flexible TCMB 3− ligand exhibits nine coordination modes and various conformations. Complex 1 is a 2D coordination polymer constructed from a [Mn(μ 2 -COO) 2 ] n linear chain and [Mn 2 (μ 2 -COO) 2 (μ 3 -COO) 2 ] n double chain combined by hexadentate TCMB 3− spacer. Complex 2 is a beautiful 2D sandwich-like network assembled by layered [Cu 3 (μ 3 -OH) 3 ] n network and typical tripodal hexadentate TCMB 3− ligand. Complex 3 is a 3D coordination polymer constructed from two distinct heptadentate TCMB 3− ligands, in which the ether oxygen atoms take part in coordination. Complex 4 exhibits a 2D double-layered network built by tetranuclear zinc cluster [Zn 4 (μ 2 -COO) 4 (μ 3 -OH) 2 ] pillared by pentadentate TCMB 3− spacer and 4-abpt linker. Complex 5 displays a 3D architecture assembled by tridentate pdta − and heptadentate TCMB 3− ligand with ether−oxygen coordination. Cobalt complexes 6−8 were prepared by similar reactions at slightly different temperatures (85, 100, and 120 °C). Complex 6 is a 3D coordination polymer assembled by tridentate TCMB 3− ligand. Complex 7 is a 3D porous MOF possessing tetranuclear cobalt cluster [Co 4 (μ 2 -COO) 3 (μ 3 -COO) 2 (μ 3 -OH) 2 ] combined by hexadentate and tetradentate TCMB 3− ligands. Complex 8 is a cluster-based 3D porous MOF, which is an isomer of 7 and contains a different tetranuclear cluster [Co 4 (μ 2 -COO) 6 (μ 3 -OH) 2 ] and pentadentate TCMB 3− ligand. PXRD study reveals the hydrolysis reaction mechanism. A hydrolysis controlled synthesis strategy is suggested based on K sp values of metal hydroxides. Their thermal stabilities were investigated. Complexes 1, 2, 7 and 8 present antiferromagnetic and/or ferromagnetic interactions. Their magnetostructural correlations are studied.

No abstract

No abstract