Synthesis and heterodimetallic complexes of lateral macrobicyclic cryptands

Carroy, A.; Lehn, Jean-Maríe

doi:10.1039/c39860001232

Cited by 43 publications

(29 citation statements)

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“…Protonation of these nitrogen atoms has been observed in the solid-state structure of (H 2 L 5 )(ClO 4 ) 2 . [40] The protonation constants determined for L 2 and L 8 are lower than those reported for the parent crown ether 4,13-diaza- [18]crown-6 (log K 1 = 9.40 and log K 2 = 7.47 in 95 % methanol, I = 0.1  Et 4 NClO 4 , 25°C). [41] This is in accordance with previous observations in which a diminution of the amine basicity has been observed upon N-alkylation of oxa-aza crown ligands.…”

Section: Thecontrasting

confidence: 50%

“…Moreover, they contain convergent binding groups that can be especially designed to match the functionality of the guest molecule. It has been shown that lateral macrobicycles behave as very versatile receptors that can be used as platforms to obtain mono- [13][14][15][16] and bimetallic [17] complexes with many different aims (i.e., to induce processes of "push-pull" dimetallic substrate activation) [18] and as receptors for organic molecules, [19] anions, [20] or contact-ion pairs. [21,22] We are interested in the relation between structure and stability of lead(II) complexes with macrocyclic ligands derived from crown ether platforms, as well as in the role of the lone-pair activity of Pb II in these kind of compounds.…”

Section: Introductionmentioning

confidence: 99%

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Lead(II) Complexes of Lateral Macrobicyclic Receptors That Incorporate a Crown Moiety and a Pyridine Head Unit

et al. 2010

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The coordinative properties towards lead(II) of two lateral macrobicyclic receptors that incorporate either a 1,10-diaza-crown-6 (L 8 ) fragment are reported. Spectrophotometric titrations performed in acetonitrile solution indicate only the formation of mononuclear complexes in solution. The X-ray crystal structures of the two receptors show that the conformation adopted by the ligand is imposed by the presence of intramolecular hydrogenbonding interactions that involve the secondary amine groups and the pivotal nitrogen atoms. The solid-state structure of [Pb(L 7 )(NCS)](SCN)·0.5H 2 O shows that the metal ion is asymmetrically coordinated inside the macrobicyclic cavity. The Pb II ion is coordinated to the nitrogen atom of the pyridine unit, the two secondary amine atoms, two oxygen

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Section: Thecontrasting

confidence: 50%

Section: Introductionmentioning

confidence: 99%

Lead(II) Complexes of Lateral Macrobicyclic Receptors That Incorporate a Crown Moiety and a Pyridine Head Unit

et al. 2010

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“…Moreover, they offer the advantage of being preorganised and therefore capable of profiting from the thermodynamic macrobicyclic effect. It has been shown that lateral macrobicycles behave as very versatile receptors that can be used as platforms to obtain homo-and heterometallic dinuclear complexes with many different aims, that is, to induce processes of "push-pull" dimetallic substrate activation [22] and as receptors for organic molecules [23] or contact ion pairs. [24,25] However, to date the recognition of anions by this type of receptor has remained much less explored than cation recognition.…”

Section: Introductionmentioning

confidence: 99%

Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition

Esteban‐Gómez

Platas‐Iglesias

Blas

et al. 2008

Chemistry A European J

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In this paper, we report two macrobicyclic receptors containing pyridine head units derived from 1,10-diaza-15-crown[5] (L1) or 4,13-diaza-18-crown[6] (L2) that can be protonated in MeCN and used for anion recognition. The interaction of these protonated lateral macrobicycles with different anions has been investigated by means of spectrophotometric titrations in MeCN. The association constants for the complexes of halide anions with the protonated macrobicycles follow the sequences Cl(-)>Br(-)>I(-)>F(-) (L1) and Cl(-)>F(-)>I(-)>Br(-) (L2), whereby an increase of more than two logarithmic units is observed from F(-) to Cl(-) for the binding constants of the receptor derived from L1. The association constants also indicate an important degree of selectivity of these macrobicyclic receptors for Cl(-) over Br(-) or I(-). The X-ray crystal structure analyses of the chloride and bromide complexes confirms the formation of the envisaged supramolecular complexes. Moreover, the binding constants indicate that these receptors present a high sulfate-to-nitrate binding selectivity. The stability trend observed for the recognition of halide anions by the macrobicycles presented herein as well as the sulfate-to-nitrate binding selectivity have been rationalised by means of DFT calculations at the B3LYP/LanL2DZ level. These studies indicate that the especially high binding selectivity for Cl(-) is the result of the optimum fit between the protonated macrobicyclic cavity and the size of the anion, whereas the sulfate-to-nitrate selectivity results from shape complementarity between the hydrogen-binding acceptor sites on sulfate and the hydrogen-bond donors of the macrobicycle.

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“…The electrophilic character of the uranyl system has been well documented, especially its ability to coordinate organic carbonyl groups, such as that of urea, in its planar fifth coordination site,19 or to act as an electrophilic catalyst for Michael additions13a and acyl‐transfer reactions 20. Detection of an intramolecular interaction of the (NS 2 )Rh–CO group with crown‐ether‐complexed alkaline metal ions has been attempted 15b…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of a Novel Heteroditopic Macrocyclic System – Monometallic Nickel(II) and Uranyl Complexes and Their Corresponding Heterobimetallic Carbonylrhodium(I) Complexes

et al. 2006

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A novel heteroditopic macrocyclic ligand system for selective coordination of two different transition metal ions has been obtained in the form of monometallic salen complexes of Ni II (LNi, 1) and uranyl (LUO 2 , 2). The system is characterized by the presence of a dianionic, tetradentate salen donor system (N 2 O 2 ) derived from cis-1,2-diaminocyclohexane and of a neutral, tridentate 2,6-bis(alkylthiomethyl)pyridine group (NS 2 ). The two binding sites are connected by two oxyethyl chains. The synthetic procedure involves the coupling of the disodium salt of 2,6-bis(mercaptomethyl)pyridine with two equivalents of 3-(2-bromoethoxy)-2-(2-propenyloxy)benzaldehyde. Removal of the protecting allyl groups from the reaction product (I) by palladium catalysis yields the ligand synthon 2,6-bis[2-(3-formyl-2-hydroxyphenyl)oxyethyl]thiomethylpyridine (II). The monometallic macrocyclic complexes 1 and 2, obtained by metal-templated synthesis from cis-1,2-diaminocyclohexane, ligson II, and the corresponding Ni II or

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Synthesis and heterodimetallic complexes of lateral macrobicyclic cryptands

Abstract: The macrobicyclic molecules (la-c) have been synthesized; they are heteroditopic ligands combining a 'soft' and a 'hard' binding subunit, which form lateral dinuclear cryptates such as [Rh+-CO, Mn+ C (la-c)] by selective complexation to a given site.

Cited by 43 publications

References 0 publications

Lead(II) Complexes of Lateral Macrobicyclic Receptors That Incorporate a Crown Moiety and a Pyridine Head Unit

Lead(II) Complexes of Lateral Macrobicyclic Receptors That Incorporate a Crown Moiety and a Pyridine Head Unit

Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition

Synthesis and Characterization of a Novel Heteroditopic Macrocyclic System – Monometallic Nickel(II) and Uranyl Complexes and Their Corresponding Heterobimetallic Carbonylrhodium(I) Complexes

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