We report that the polarity and dielectric constants of solvents used for grafting organosilanes on mesoporous materials strongly affect the concentration of grafted organic groups, the degree of their site-isolation, and the catalytic properties of the resulting materials. Polar and nonpolar organosilanes as well as polar-protic, dipolar-aprotic, and nonpolar solvents were investigated. Polar-protic solvents, which have high dielectric constants, resulted in smaller concentrations ( approximately 1-2 mmol/g) of polar organic groups such as 3-aminopropyl groups, higher surface area materials, site-isolated organic groups, and more efficient catalytic properties toward the Henry reaction of p-hydroxybenzaldehyde with nitromethane. On the other hand, dipolar-aprotic and nonpolar solvents resulted in larger concentrations ( approximately 2-3 mmol/g) of grafted polar functional groups, lower-to-higher surface area materials, more densely populated catalytic groups, and poor-to-efficient catalytic properties toward the Henry reaction. Both the polar-protic and dipolar-aprotic solvents resulted in significantly lower concentration of grafted groups for nonpolar organosilanes such as (3-mercaptopropyl)trimethoxysilane compared to corresponding grafting of the polar amino-organosilanes. The relationship between the solvent properties and the percentage and degree of site-isolation of the grafted functional groups was attributed to differences in solvation of the organosilanes and silanols in various solvents and possible hydrogen-bonding between the organsilanes and the solvents. The degree of site-isolation of the amine groups, which affect the material's catalytic properties, was elucidated by a new colorimetric method involving probing of the absorption maxima (lambdamax) on the d-d electronic spectrum of Cu2+ complexes with the amine-functionalized materials and the colors of the samples. The absorption lambdamax and the colors of the materials were found to be uniquely dependent on the type of solvents used for grafting the organoamines. For instance, the monoamine- and diamine-functionalized samples grafted in methanol resulted in pale blue and light purple colors with lambdamax at approximately 720 and 650 nm, respectively. These correspond to CuNO5 and CuN2O4 structures, respectively, which are indicative of the presence of site-isolated organoamines in samples grafted in methanol. The monoamine and diamine samples grafted in toluene resulted in purple and deep purple colors with lambdamax at approximately 590 and 630 nm, respectively. These correspond to CuN2O4 and CuN4O2, which are indicative of the presence of closely spaced organoamines in samples grafted in toluene. The samples grafted in isopropanol gave colors and lambdamax intermediate between those of samples grafted in toluene and methanol.

We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500 microg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM-41 had no noticeable effect on respiration rate. In cells depleted of metabolic fuels, 50 microg/mL SBA-15 delayed the onset of glucose-supported respiration by 12 min and 200 microg/mL SBA-15 by 34 min; MCM-41 also delayed the onset of glucose-supported respiration. Neither SBA-15 nor MCM-41 affected cellular glutathione. Both nanoparticles inhibited respiration of isolated mitochondria and submitochondrial particles.

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A synthetic method for controlling the Henry reaction products from nitrostyrene to nitroalcohol in heterogeneous catalysis by a simple change of the catalytic sites in organoamine-functionalized mesoporous catalysts is reported. The synthesis resulted in either b-nitrostyrene or b-nitroalcohol by simple change of the types of amine functional groups in the amine-functionalized mesoporous catalysts from primary amines into secondary or tertiary.

Recyclable and efficient heterogeneous catalysts have been prepared by embedding dirhodium(II,II) core carboxylate complexes into the amine‐functionalized nanosized channels of a mesoporous silica host, amine–SBA‐15. Two alternative synthetic procedures for the preparation of the catalysts have been developed and adapted for the immobilization of dirhodium complexes of variable Lewis acidity. The catalytic activity of the resulting solid materials has been evaluated in model cyclopropanation reactions of styrene at variable reaction conditions (reaction substrate, temperature, time, and solvent). Importantly, the designed catalysts, which can be readily recovered and reused, display the reactivity and selectivity profiles exceeding or comparable to their homogeneous dirhodium(II) counterparts.

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The sections in this article are Introduction: Core‐Shell Nanomaterials and Their Biological/Medical Applications Nonmagnetic Core‐Shell Nanomaterials Synthesis of Cores in Core‐Shell Nanostructures Metal Cores Metal Oxide Cores Polymeric Cores Semiconductor Cores Deposition of Shells over the Core Nanomaterials Types of Core‐Shell Nanomaterial Metal–Insulator Core‐Shell Nanomaterials Metal‐Dense Metal Oxide Core‐Shell Nanomaterials Metal‐Functionalized Metal Oxide Core‐Shell Nanoparticles Metal–Porous Metal Oxide Core‐Shell Metal–Polymer Core‐Shell Nanoparticles Hollow Metal–Metal Oxide Shells by Controlled Core‐Dissolution Metal Core–Dendrimer Core‐Shell Nanoparticles Metal Core–Semiconducting Metal Oxide Shell Nanoparticles Insulator–Metal Core‐Shell Nanomaterials Metal Oxide–Metal Core‐Shell Nanostructures Polymer–Metal Core‐Shell Nanostructures Insulator–Insulator Core‐Shell Nanoparticles Polymer–Metal Oxide Core‐Shell Nanomaterials Polymer–Polymer Core‐Shell Nanomaterials Biomolecule (Protein) Core–Polymer Shell Core‐Shell Nanoparticles Metal Oxide–Metal Oxide Core‐Shell Nanomaterials Metal Oxide–Dye‐Doped Silica and Dye‐Doped Silica–Metal Oxide Core‐Shell Nanostructures Metal Oxide–Polymer Core‐Shell Nanoparticles Other Inorganic Materials Cores: Metal Oxide Shells Semiconductor–Insulator Core‐Shell Nanomaterials Semiconductor–Semiconductor Core‐Shell Nanomaterials Semiconductor–Semiconductor–Dendrimer Core‐Shell‐Shell Nanoparticles Insulator–Semiconductor Core‐Shell Nanomaterials Metal–Metal Core‐Shell Insulator–Metal Core‐Shell Nanoparticles Carbon‐Containing Core‐Shell Nanomaterials Metal Oxide–Carbon Core‐Shell Nanoparticles Other Carbon‐Containing Core‐Shell Nanomaterials Synthetic Methods to Create Core‐Shell Nanomaterials, and their Characterizations Applications Applications in Biology and Medicine Bioimaging and Immunoassay Drug or Biomolecular Delivery Vehicles Core‐Shell Nanomaterials for Catalysis Conclusions and Future Prospects Acknowledgments

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