Carboxyl and amino-functionalized polystyrene latex particles were synthesized by the miniemulsion copolymerization of styrene and acrylic acid or 2-aminoethyl methacrylate hydrochloride (AEMH). The reaction was started by using an oil-soluble initiator, such as 2,2'-azobis(2-methylbutyronitrile) (V-59). The effect of the functional monomer content and type of surfactant (non-ionic versus ionic) on the particle size and particle size distribution was investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). A bimodal particle size distribution was observed for functionalized latex particles prepared in the presence of the non-ionic surfactant (i.e., Lutensol AT-50) when 1 wt % of acrylic acid or 3 wt % of AEMH as a comonomer was employed. The copolymer particle nucleation was studied by using a highly hydrophobic fluorescent dye. From the obtained results, the formation of bimodal particle size distribution may be attributed to a budding-like effect, which takes place during the earlier stage of polymerization and is caused by the additional stabilizing energy originated from the ionic groups of a functional polymer. The reaction mechanism of particle formation in the presence of non-ionic and ionic surfactants has been proposed. The amount of the surface functional groups was determined from polyelectrolyte titration data.

Chemical functionalization of molecular 2D materials toward the assembly of hierarchical functional nanostructures is of great importance for nanotechnology including areas like artificial photocatalytic systems, nanobiosensors, or ultrafiltration. To achieve the desired functionality of 2D materials, these need to be characterized down to the nanoscale. However, obtaining the respective chemical information is challenging and generally requires the application of complementary experimental techniques. Here, the synthesis and chemical characterization of hierarchically assembled molecular nanosheets based on ≈1 nm thin, molecular carbon nanomembrane (CNM) and covalently grafted, single‐molecule layer cobalt(III) catalysts for the light‐driven hydrogen evolution reaction (HER) is demonstrated. X‐ray photoelectron spectroscopy (XPS) and tip‐enhanced Raman spectroscopy (TERS) to access both the transversal and longitudinal chemical information of the synthesized nanosheets with nanometer resolution are employed. TERS and XPS data provide detailed information on the average and local surface distribution of the catalyst as well as mechanistic details of the grafting reaction. The proposed approach represents a general route toward a nanoscale structural analysis for a variety of molecular 2D materials—a rapidly growing materials class with broad prospects for fundamental science and applications.

Chemical functionalization of molecular two-dimensional (2D) materials towards the assembly of hierarchical functional nanostructures is of great importance for nanotechnology including areas like artificial photocatalytic systems, nanobiosensors or ultrafiltration. To achieve the desired functionality of 2D materials, these need to be characterized down to the nanoscale. However, obtaining the respective chemical information is challenging and generally requires the application of complementary experimental techniques. Here, we demonstrate the synthesis and chemical characterization of hierarchically assembled molecular nanosheets based on about 1 nm thin, molecular carbon nanomembrane (CNM) and covalently grafted, single-molecule layer cobalt(III) catalysts for the light-driven hydrogen evolution reaction (HER). We employ X-ray photoelectron spectroscopy (XPS) and tip-enhanced Raman spectroscopy (TERS) to access both the transversal and lateral chemical information of the synthesized nanosheets with nanometer resolution. TERS and XPS data provide detailed information on the average and local surface distribution of the catalyst as well as mechanistic details of the grafting reaction. The proposed approach represents a general route towards a nanoscale structural analysis for a variety of molecular 2D materials - a rapidly growing materials class with broad prospects for fundamental science and applications.

Propyne iminium triflates 1–6 react as dipolarophiles in thermal [3 + 2]-cycloadditions with sufficiently electron rich organoazides to form 1,4,5-trisubstituted 1,2,3-triazoles with iminium functionalization. The reactions require rather strong thermal activation, but can be accelerated by microwave irradiation. The regioselectivity of the cycloaddition at the internal acetylenic bond of 3-cyclopropylpropyne and 3-arylpropyne iminium ions (1–3 and 4, respectively) is very high, but is lowered in the presence of sterically demanding substituents at the opposite end of the iminium-substituted C,C triple bond. The iminium-functionalized triazoles can easily be transformed into neutral compounds; herein reported is the formation of triazolyl ketones 10 by hydrolysis and of tertiary triazolyldimethyl amines 12 by LiAlH4 reduction. When the reduction is performed with sodium boranate or sodium cyanoboranate, amine–borane complexes 15 and 16 are obtained.