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Molecular templates can be used in many different ways to control the outcome of chemical reactions. Here we present a new type of template-directed synthesis. We show that templates can be used as shadow masks: the shape of the template becomes imprinted on the product because reaction only occurs at sites not masked by the template. We demonstrate this effect by using oligopyridine templates to dictate the sites of demetallation when a magnesium porphyrin nanoring is treated with acid. Magnesium centers that are coordinated to the template are protected whereas uncoordinated magnesium centers are removed. After site-selective demetallation, the template can be removed and other cations, such as zinc(II) and copper(II), can be inserted into the free-base porphyrin centers. This strategy provides a simple route to a wide range of heterometallated porphyrin arrays.
This article was published in the following journal.
Name: Angewandte Chemie (International ed. in English)
This Account is about templates as construction tools: molecules for making molecules. A template organizes the reactants and provides information to promote formation of a specific product, but it is...
MFM-300(Al) shows reversible uptake of NH3 (15.7 mmol g-1 at 273 K and 1.0 bar) over 50 cycles with an exceptional packing density of 0.62 g cm-3 at 293 K. In situ neutron powder diffraction and synch...
Heterogeneous copper sulfide-based nanostructures have attracted intense attention based on their potential to combine the plasmonic properties of copper-deficient copper sulfides with properties of o...
Magnesium(I) halides (Mg(I)X; X = Cl, Br, I) as high temperature molecules are trapped and finally stored at -80 °C in toluene/donor solutions. These solutions provide insights into the fundamental m...
Six new 2-fold interpenetrated uranyl coordination polymers with two distinct types of (6,3)-net layers, (HO)[(UO)(L)]·HO (1), (Hbipy)[(UO)(L)]·HO (2), (Hbib)[(UO)(L)]·HO (3), (Hdib)[(UO)(L)]·HO (...
The primary objective of this clinical trial is to demonstrate the superiority of Natural Calm magnesium powder with respect to absorption when compared to three marketed forms of magnesiu...
In this randomized cross over study the investigators will evaluate the effects on gas exchange and patients' tolerance of a new CO2 non rebreathing devices incorporated in the mask vs the...
The purpose of the Optimize RV Follow-Up study is to determine the long-term effect of selective site pacing. Selective site pacing refers to which area of the right ventricle the lead is ...
This four-arm randomized controlled trial was designed to study the effects of magnesium supplements (total daily dose: 450 mg elemental magnesium) on vascular stiffness in healthy overwei...
This study aims to determine how a 6-week magnesium supplementation with 400 mg magnesium from magnesium citrate/magnesium oxide affects stress parameters in students in exam preparation.
A nutritional condition produced by a deficiency of magnesium in the diet, characterized by anorexia, nausea, vomiting, lethargy, and weakness. Symptoms are paresthesias, muscle cramps, irritability, decreased attention span, and mental confusion, possibly requiring months to appear. Deficiency of body magnesium can exist even when serum values are normal. In addition, magnesium deficiency may be organ-selective, since certain tissues become deficient before others. (Harrison's Principles of Internal Medicine, 12th ed, p1936)
Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)
Magnesium chloride. An inorganic compound consisting of one magnesium and two chloride ions. The compound is used in medicine as a source of magnesium ions, which are essential for many cellular activities. It has also been used as a cathartic and in alloys.
An intra-extracellular electrolyte exchange agent with a variety of effects.
The technique of spraying a tissue specimen with a thin coat of a heavy metal such as platinum. The specimen is sprayed from an oblique angle, which results in the uneven deposition of the coating. The varying thicknesses create a shadow effect and give a three-dimensional appearance to the specimen.