Metallacrown complexes

Figure 2.43 Eiquid-crystalline copper(I) metallacrown complexes used for the preparation of phosphorescent paper (R = C H2 +i n — 12, 18)...

Lehaire, M.-L. Scopelliti, R. Piotrowski, H. Severin, K. Selective recognition of fluoride anion using a Li -metallacrown complex. Angew. Chem. Int. Ed. 2002, 41, 1419-1422. 

Severin and coworkers synthesized an organometallic metallacrown complex The receptor was found to... 

The metallacrown complex Eu(N03)2[15-MCcu(ii)N(pic)-15] N03 is synthesized by dissolving Cu(OAc)2 H2O (0.40 g, 2 mmol) in 50 mL of DMF in a 500 mL Erlenmeyer flask. To this solution is added H2picHA (0.28g, 2 mmol) dissolved in 50 mL of DMF. The solution is allowed to stir for one hour, at which point solid Eu(N03)3 6H2O (0.18 g, 0.4 mmol) is added, and the solution is stirred for several hours. Slow evaporation of the solvent results in a 79% yield of dark green, rhombic crystals. (The checkers found it necessary to reduce the volume of the solution to a third of the original volume before crystals formed.) These crystals, obtained in 71% yield, were washed with ether, were dried, and gave satisfactory elemental analysis. 

Tiivedi ER, Eliseeva SV, Jankolovits J, Olmstead MM, Petoud S, Pecoraro VL (2014) Highly emitting near-infrared lanthanide encapsulated sandwich metallacrown complexes with excitation shifted toward lower energy. J Am Chem Soc 136(4) 1526-1534... 

On the contrary, encapsulation of the larger K" " or NH4 ions should lead to the formation of metallacrown ether sandwich complexes (M+ MC= 1 2). Reaction of diethyl ketipinate H2L 13 with copper(ll) acetate in the presence of calcium nitrate affords green microcrystals 14 after crystallization from tetrahydro-furan/diethyl ether (Scheme 1). 

For the unequivocal characterization of the molecular structure of 19, an X-ray crystallographic structure analysis was carried out [46]. According to this analysis, 19 is present in the crystal as a cyclic iron(lll) complex with a [12]metallacrown-6... 

The tetranuclear copper(Il) complex 8 [38,40], prepared with /1-alanine-hydroxamic acid, displays an almost planar conformation of the macrocycle. Schematic diagrams of [9]crown-3 (9-C-3) 9 and [12]crown-4 (12-C-4) 10 are compared with the analogous cores of the metallacrovms [9]metallacrown-3 (9-MC-3) 7 and [12]metallacrown-4 (12-MC-4) 8. 

Crown ethers selectively complex alkaline ions [6,41], and the complexation of different sized cations leads to coronates [5,42] of various structures. The structural analogy between crown ethers and their topologically equivalent metallacrown ethers... 

Figure 11.27 (a) Structure of a [12]metallacrown-3 derivative and (b) X-ray molecular structure of an analogous hexanuclear complex based on ligands bridging two trimers. ... 

PPh2(CH2CH2O) CH2CH2PPh2) complexes have been prepared and the X-ray structure of the metallacrown ether for n = 3 has been reported.The new ligand... 

USE OF SALICYL- AND NAPHTHOYLHYDROXIMATE COMPLEXES IN PREPARATION OF MANGANESE AND COPPER 12-METALLACROWN-4 COMPLEXES Mn(II)(ACETATE)2[Mn(III)(SALICYLHYDROXIMATE)]4 AND (TETRAMETHYLAMMONIUM)2[Cu(n)5 (NAPHTH0YLHYDR0XIMATE)4]... 

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