A Polyhedral Host Constructed Using a Linear Template

Abstract

A linear template is used to direct the synthesis of a "head-to-head" tetrapyridine in the solid state, which, in a second step, assembles with a transition-metal-ion to form a polyhedral metal-organic host with a structure that conforms to a trigonal antiprism. The application of the linear template is reminiscent of the synthetic strategy of nature.

Styryl dyes. Synthesis and study of the solid-state [2+2] autophotocycloaddition by NMR spectroscopy and X-ray diffraction

“…The chemical shifts and spin spin coupling con stants were measured with an accuracy of 0.01 ppm and 0.1 Hz, respectively. The assignment of the signals for the protons was made based on two dimensional homonuclear 1 (2,3,5,6,8,9,11,12,14 Synthesis of styryl dyes 1b-d and 2a,b (general procedure). A solution of 4 styrylpyridine 6a or 7a,b (0.5 mmol) and iodoethane, 1 iodobutane, or 2 iodopropane (3.0 mmol) in dichloromethane (5-10 mL) was kept in the dark at ~20 °C for 2-4 weeks.…”

“…[3][4][5][6][7][8][9][10][11] The advantages of this method for the car bon-carbon bond formation are the relative simplicity of the synthesis (irradiation of samples with light of a speci fied wavelength), the reversibility of the reaction, which allows the regeneration of the starting compounds by changing the wavelength, and, in some cases, high stereoselectivity of PCA reactions resulting from the preorganization of pairs of the starting structural units. It should also be noted that the preparation of many PCA reaction products with the use of other synthetic ap proaches presents difficulties.…”

“…In the present study, we performed the 1 H NMR spec troscopic investigation of the ability of styryl dyes of the pyridine (1-4) and benzothiazole (5) series to be in volved in the [2+2] autophotocycloaddition reaction in thin polycrystalline films depending on the structure of the dye and determined the compositions and three di mensional structures of the final products (cyclobutane derivatives). Most of the dyes were characterized by X ray diffraction, and the packing modes formed by the dyes were analyzed in terms of the preorganization of the dye molecules for the solid state photochemical cycload dition.…”

Metallo-supramolecular capsules

“…Somewhat related to the research mentioned above, recent work by MacGillivray and co-workers have used crystal engineering to controllably assemble materials that can undergo [2 + 2] photodimerisation [37]. By doing so, the authors have prepared an otherwise unobtainable cyclobutane functionalised with two 2-pyridyl and two 4-pyridyl groups.…”

“…The trigonal antiprsimatic structure formed by combination of novel cyclobutane tetra-pyridyl ligands with copper centres. The resulting void in the framework is filled with two perchlorate anions [37]. X-ray diffraction (an example of which is shown in Fig.…”