Synthesis and spectroscopy of new iron(II) complexes of 4,7-bis(aza-crown ether)-phenanthrolines with unusual complexation properties

Abstract

Footnotest Satisfactory C, H, N analyses were obtained for all iron(1r) complexes.8 The charge to radius values for K+ and Ba2+ are 0.72 X 10-2 and 1.48 x 10-2 A s pm-1, respectively. AE, separation of anodic and cathodic peak potential.

Synthesis of Macropolycycles Comprising Diazacrown and Adamantane Moieties via Pd -Catalyzed Amination Reaction

“…These compounds were formed primarily with para-bromobenzyl derivatives 5 and 6 and their yields were comparable with those of macrobicycles (entries 5,7,8). This fact can be also explained by the higher sterical demands of bis(4-bromobenzyl) substituted diazacrown ethers which hindered the intramolecular di-amination and decreased the yields of macrobicycles 11, 14 simultaneously boosting the formation of cyclic oligomers.…”

“…Also the diamine 7a is more rigid compared to the diamine 7b, thus the geometric demands for a successful cyclization with this diamine are stricter. Derivatives of the 3-bromobenzyl substituted diazacrown ethers 3 and 4 provided higher yields of the macrobicycles 8 and 10 (entries 1-4) if compared with 4-bromobenzyl substituted diazacrowns 5 and 6 (entries [5][6][7][8]. This fact might be also explained by a better adjustment of two bromine atoms to the nitrogen atoms of diamines in the diazacrown ethers with meta-bromobenzyl substituents.…”

“…In particular, bis(azacrown) ethers with isolated macrocycles linked via aliphatic bridges were described, [1] as well as the molecules with spiro-conjugated macrocycles, [2] and with condensed macro rings possessing saturated and unsaturated cyclic spacers. [3] The majority of known bis(azacrown) ethers possess two macrocyclic units which are symmetrically arranged around the aromatic, [4,5] matallocene, [6] porphyrin, [7] or calixarene [8] spacer. A special attention has been paid to the macrobicycles of the cryptand type derived from azacrown ethers: known are di-and triazapolyoxacryptands, [9,10] benzocryptands containing fragments of 1,2-, 1,3-, and 1,4-disubstituted benzene, [11,12] 2,6-disubstituted pyridine, [13] described are the compounds in which two diazacrown ethers are combined in macrotricyclic systems via aliphatic [14] or benzyl [15] linkers.…”

Ditopic Macrocyclic Receptors with a 4,7‐Diamino‐1,10‐phenanthroline Fragment for Multimodal Detection of Toxic Metal Ions

“…Mixed‐donor macrocycles (Scheme ) are the most widely used receptors because they are more or less preorganized for metal ion binding. To prepare these receptors, nucleophilic substitution reactions (S N Ar) are usually employed; these proceed under harsh reaction conditions or microwave heating and often an excess of nucleophile is needed. This methodology is difficult to adopt for the synthesis of ditopic receptors with fused receptor sites (Scheme , series B ) and these molecules are still scarcely studied.…”

The Photochemistry of a bis‐Crown Ether Based on Benzobis(thiazole) and Its Alkaline Earth Metal Cation Complexes

“…Ligands possessing two‐crown ether moieties are known to have a greater effect on increasing the binding ability of cations, compared with the corresponding parent mono‐crown ethers, particularly favoring large cations and acting through ditopic sandwich complexation (5–8). Fluoroionophores based on phenanthroline or squaraine central units bearing two‐crown ether moieties have been reported (9–11) but their photophysical properties have not been extensively studied. Photoregulation of the relative position of the two‐crown ether moieties has been sought by incorporating them on a photochromic core (12–16).…”