-Heterocyclic Carbene-Stabilized Atomically Precise Metal Nanoclusters.

This perspective highlights advances in the preparation and understanding of metal nanoclusters stabilized by organic ligands with a focus on -heterocyclic carbenes (NHCs). We demonstrate the need for a clear understanding of the relationship between NHC properties and their resulting metal nanocluster structure and properties. We emphasize the importance of balancing nanocluster stability with the introduction of reactive sites for catalytic applications and the importance of a better understanding of how these clusters interact with their environments for effective use in biological applications.

Combined thermal ablation and liposomal granulocyte-macrophage colony stimulation factor increases immune cell trafficking in a small animal tumor model.

Purpose: To characterize intratumoral immune cell trafficking in ablated and synchronous tumors following combined radiofrequency ablation (RFA) and systemic liposomal granulocyte-macrophage colony stimulation factor (lip-GM-CSF).

Methods: Phase I, 72 rats with single subcutaneous R3230 adenocarcinoma were randomized to 6 groups: a) sham; b&c) free or liposomal GM-CSF alone; d) RFA alone; or e&f) combined with blank liposomes or lip-GM-CSF. Animals were sacrificed 3 and 7 days post-RFA.

NHC-Stabilized Au Nanoclusters and Their Conversion to Au Nanoclusters.

Herein, we describe the synthesis of a toroidal Au cluster stabilized by -heterocyclic carbene and halide ligands reduction of the corresponding NHC-Au-X complexes (X = Cl, Br, I). The significant effect of the halide ligands on the formation, stability, and further conversions of these clusters is presented. While solutions of the chloride derivatives of Au show no change even upon heating, the bromide derivative readily undergoes conversion to form a biicosahedral Au cluster at room temperature.

N-Heterocyclic Carbene-Stabilized Hydrido Au Nanoclusters: Synthesis, Structure, and Electrocatalytic Reduction of CO.

Atomically precise hydrido gold nanoclusters are extremely rare but interesting due to their potential applications in catalysis. By optimization of molecular precursors, we have prepared an unprecedented N-heterocyclic carbene-stabilized hydrido gold nanocluster, [Au(NHC)ClH]. This cluster comprises a dimer of two Au kernels, each adopting an icosahedral shape with one missing vertex.

Synthesis and enantioseparation of chiral Au nanoclusters protected by bis--heterocyclic carbene ligands.

A series of chiral Au nanoclusters were synthesized the direct reduction of achiral dinuclear Au(i) halide complexes ligated by -xylyl-linked bis--heterocyclic carbene (NHC) ligands. A broad range of functional groups are tolerated as wingtip substituents, allowing for the synthesis of a variety of functionalized chiral Au nanoclusters. Single crystal X-ray crystallography confirmed the molecular formula to be [Au(bisNHC)Cl]Cl, with a chiral helical arrangement of the five bidentate NHC ligands around the icosahedral Au core.