An all-in-one approach for synthesis and functionalization of nano colloidal gold with acetylacetone

Controllable synthesis, proper dispersion, and feasible functionalization are crucial requirements for the application of nanomaterials in many scenarios. Here, we report an all-in-one approach for the synthesis and functionalization of gold nanoparticles (AuNPs) with the simplest β-diketone, acetylacetone (AcAc). With this approach, the particle size of the resultant AuNPs was tunable by simply adjusting the light intensity or AcAc dosage. Moreover, owing to the capping role of AcAc, the resultant AuNPs could be stably dispersed in water for a year without obvious change in morphology and photochemical property. Formation of ligand to metal charge transfer complexes was found to play an important role in the redox conversion of Au with AcAc. Meanwhile, the moderate complexation ability enables the surface AcAc on the AuNPs to undergo ligand exchange reactions. With the aid of Ag+, the AuNPs underwent ligand exchange reaction with glutathione and exhibited enhanced photoluminescence (PL) with a maximum of 22-fold increase in PL intensity. The PL response was linear to the concentration of glutathione in the range of 0~500 μM. Such a ligand exchange reaction makes the obtained AuNPs being good imaging probes. To the best of our knowledge, this is the first work on illustrating the roles of AcAc as a multifunctional ligand in fabrication of NPs, which sheds new light on the surface modulation in synthesis of nanomaterials.

DMSA-coated cubic iron oxide nanoparticles as potential therapeutic agents

Aim: Superparamagnetic cubic iron oxide nanoparticles (IONPs) were synthesized and functionalized with meso-2,3-dimercaptosuccinic acid (DMSA) as a potential agent for cancer treatment. Methods: Monodisperse cubic IONPs with a high value of saturation magnetization were synthesized by thermal decomposition method and functionalized with DMSA via ligand exchange reaction, and their cytotoxic effects on HeLa cells were investigated. Results: DMSA functionalized cubic IONPs with an edge length of 24.5 ± 1.9 nm had a specific absorption rate value of 197.4 W/gFe (15.95 kA/m and 488 kHz) and showed slight cytotoxicity on HeLa cells when incubated with 3.3 × 1010, 6.6 × 1010 and 9.9 × 1010 NP/mL for 24, 48 and 72 h. Conclusion: To the best of our knowledge, this is the first study to investigate both the cytotoxic effects of DMSA-coated cubic IONPs on HeLa cells and hyperthermia performance of these nanoparticles.

Short X···N Halogen Bonds With Hexamethylenetetraamine as the Acceptor

Hexamethylenetetramine (HMTA) and N-haloimides form two types of short (imide)X···N and X–X···N (X = Br, I) halogen bonds. Nucleophilic substitution or ligand-exchange reaction on the peripheral X of X–X···N with the chloride of N-chlorosuccinimide lead to Cl–X···N halogen-bonded complexes. The 1:1 complexation of HMTA and ICl manifests the shortest I···N halogen bond [2.272(5) Å] yet reported for an HMTA acceptor. Two halogen-bonded organic frameworks are prepared using 1:4 molar ratio of HMTA and N-bromosuccinimide, each with a distinct channel shape, one possessing oval and the other square grid. The variations in channel shapes are due to tridentate and tetradentate (imide)Br···N coordination modes of HMTA. Density Functional Theory (DFT) studies are performed to gain insights into (imide)X···N interaction strengths (ΔEint). The calculated ΔEint values for (imide)Br···N (−11.2 to −12.5 kcal/mol) are smaller than the values for (imide)I···N (−8.4 to −29.0 kcal/mol). The DFT additivity analysis of (imide)Br···N motifs demonstrates Br···N interaction strength gradually decreasing from 1:1 to 1:3 HMTA:N-bromosuccinimide complexes. Exceptionally similar charge density values ρ(r) for N–I covalent bond and I···N non-covalent bond of a (saccharin)N–I···N motif signify the covalent character for I···N halogen bonding.

Ligand exchange reactions on thiolate-protected gold nanoclusters

As a versatile post-synthesis modification method, ligand exchange reaction exhibits great potential to extend the space of accessible nanoclusters. In this review, we sumarized this process for thiolate-protected gold nanoclusters....

Macrocyclic Complexes Based on [N···I···N]+ Halogen Bond

New 1 – 2 nm macrocyclic iodine(I) complexes prepared via a simple ligand exchange reaction, manifest rigid 0.5 – 1 nm cavities that bind hexafluorophosphate anion in the gas phase....

Synthesis and reactivity of the uranium phosphinidene metallocene [5-1,3-(Me3Si)2C5H3]2U(=P-2,4,6-iPr3C6H2)(OPMe3): Influence of the coordinated Lewis base

This paper describes the synthesis and reactivity of [5-1,3-(Me3Si)2C5H3]2U(=P-2,4,6-iPr3C6H2)(OPMe3) (6) which is accessible from a ligand exchange reaction between [5-1,3-(Me3Si)2C5H3]2U(=P-2,4,6-iPr3C6H2)(OPPh3) (2) and Me3PO at ambient temperature. Phosphinidene 6 exhibits no...

Diaryliodonium Salts: Structures and Synthesis

Due to similar reactivity in comparison with aromatic organometallic reagents, diaryliodonium salts are currently in broad usage as less toxic, highly efficient, stable and mild electrophilic reagents in organic synthesis. The hypervalent iodine center of diaryliodonium salts can lead to unique reactivity, which thus is frequently presented in metal-free arylations or metal-involved elementary reactions such as oxidative addition, reduction elimination, ligand coupling and ligand exchange reaction. As such, diaryliodonium salts have experienced explosive growth by transferring aromatics to the target molecules. In contrast to the reviews on the synthetic utility or aryl transformations by using diaryliodonium salts, this review provides a summary of their structures and the synthetic strategies towards them during recent decades.