Four nickel clusters, cyclo-[{Ni(μ-S(i)Pr)(μ-SMe)}(6)] (1), cyclo-[{Ni(μ-StBu)(μ-SMe)}(6)] (2), cyclo-[{Ni(μ-S(i)Pr)(μ-SEt)}(6)] (3) and cyclo-[{Ni(μ-StBu)(μ-SEt)}(10)] (4), based on thiolate ligands have been successfully synthesized and characterized by elemental analysis, FT-IR spectra, UV-vis-NIR spectra, powder X-ray diffraction and single-crystal X-ray diffraction. Intriguingly, the SMe and SEt ligands are generated from solvothermal in situ ligand synthesis through the cleavage of the S-S bond respectively. The four nickel thiolate clusters exhibit tiara-like frameworks consisting of two different types of thiolate ligands.

A surface-engineered heterogeneous catalyst with a controllable catalytic interface is the most straightforward approach for boosting catalytic activity.

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Six nickel tiara-like clusters, cyclo-ijNiIJμ-EDT)] 5 (1), cyclo-{[NiIJμ-SiPe) 2 ] 6 } (2), cyclo-ijNi 6 IJμ-StBu) 4 IJμ-EDT) 4 ](3), cyclo-ijNi 6 IJμ-StBu) 4 IJμ-PDT) 4 ] (4), cyclo-ijNi 6 IJμ-SPh) 4 IJμ-EDT) 4 ] (5) and cyclo-ijNi 6 IJμ-SPh) 4 IJμ-PDT) 4 ] (6) (StBu = 2-methyl-2-propanethiol, EDT = 1,2-ethanedithiol, PDT = 1,3-propanedithiol, SiPe = isopentylthiol, SPh = thiophenol have been successfully synthesized and characterized. All the clusters were derived from a designed preparation by a direct synthetic route involving reactions of NiIJClO 4 ) 2 with mixed thiolate or disulfide ligands which have discrepancy in their coordination ability. Intriguingly, cluster 1 is an infrequent pentanuclear tiara. Clusters 3 and 4 are hexanuclear tiaras with two different types of mono and bidentate aliphatic thiolates. Clusters 5 and 6 exhibit similar structures with monoaromatic thiolate and bidentate aliphatic thiolate ligands. The -SPh ligands were generated from an in situ reaction of the disulfide precursor through cleavage of the S-S bond. These heretofore unknown additions to the cyclo-ijNiIJμ-SR) 2 ] n tiara family are of particular interest, which are often constructed by just one kind of thiolate ligand. CrystEngCommThis journal is

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Three complexes of gadolinium-based on dentritic molecules are reported as magnetic resonance imaging (MRI) contrast agents. Their ligands feature four carboxylate groups, which contribute to good water solubility and a strong combination with metal ions. As a new attempt, coupling polymerization is carried out to make a combination of conjugated polyelectrolytes and dendrimers for MRI contrast agents. For comparison, mononuclear and binuclear complexes are also reported. The investigation suggests that the contrast agent with the newly designed macromolecular skeleton provides higher longitudinal relaxivity value (36.2 mm s ) and more visible enhancement in in vivo and in vitro MR images than the small molecular ones. In addition, extremely low cytotoxicity and main clearance via hepatobiliary are confirmed, which reduces the deterioration of chronic kidney disease. All the results indicate that these three complexes are generally applicable as promising clinical contrast agents.