Selective recognition of tetrahedral dianions by a hexaaza cryptand receptor

Mateus, Pedro; Delgado, Rita; Brandão, Paula; Carvalho, Sílvia; Félix, Vı́tor

doi:10.1039/b912940e

Cited by 66 publications

(67 citation statements)

References 35 publications

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“…[25] Equipment and working conditions: The equipment used was described before. [26] The ionic strength of the experimental solutions was kept at (0.10 AE 0.01) mol dm À3 with KNO 3 , the temperature was maintained at (298.2 AE 0.1) K. Atmospheric CO 2 was excluded from the titration cell during experiments by passing purified nitrogen across the top of the experimental solution. Values for E'8 8, Q, E j and K' w were determined by titration of a solution of known hydrogen-ion concentration at the same ionic strength and using the acid pH range of the titration.…”

Section: à3mentioning

confidence: 99%

Recognition of Oxalate by a Copper(II) Polyaza Macrobicyclic Complex

Mateus

Delgado

Brandão

et al. 2011

Chemistry A European J

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A new polyamine macrobicyclic compound was synthesised through a [1+1] "tripod-tripod coupling" strategy and using a Schiff base condensation reaction, followed by sodium borohydride reduction. The resulting compound is a heteroditopic cage (btpN(7)) in which one of the head units is appropriate for the coordination of copper(II), whereas the other head is available for additional hydrogen-bonding and electrostatic interactions with substrates. The acid-base behaviour of the new compound, the stability constants of its complex with the Cu(2+) ion and the association constants of the copper(II) cryptate with oxalate (oxa(2-)), malonate (mal(2-)), succinate (suc(2-)), maleate (male(2-)) and fumarate (fum(2-)) were determined by potentiometry at 298.2 K in aqueous solution and at an ionic strength of 0.10 mol dm(-3) in KNO(3). These studies revealed a clear preference of the receptor [CuH(h)btpN(7)H(2)O]((2+h)+) for oxa(2-) over the other dicarboxylate substrates. This arises from co-operativity between metal-anion coordination and electrostatic and hydrogen-bonding interactions, in accordance with the ideal size of this dicarboxylate, which allow it to take full advantage of the potential binding sites of the receptor. A qualitative indicator-displacement study, in agreement with the potentiometric studies, demonstrated that the copper cryptate receptor can be used as a selective visual sensor for oxalate.

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Section: à3mentioning

confidence: 99%

Recognition of Oxalate by a Copper(II) Polyaza Macrobicyclic Complex

Mateus

Delgado

Brandão

et al. 2011

Chemistry A European J

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“…The selectivity for different anions can be tuned by controlled protonation of the pyridylic and xylylic cage compounds. [39,40] The binding of the anions occurs predominately within the cavities of the cage compounds, which was proved in several cases by X-ray crystal structure analysis (see, for example, Figure 3).…”

Section: Cage Compounds Through Formation Of Imine Bondsmentioning

confidence: 92%

“…Reproduced from Ref. [40] with permission from the Royal Society of Chemistry. [46] functional polymers, [47] as well as discrete molecules, such as dendrimers.…”

Section: Cage Compounds Through Formation Of Boronic Estersmentioning

confidence: 99%

Shape‐Persistent Organic Cage Compounds by Dynamic Covalent Bond Formation

2010

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One area of supramolecular chemistry involves the synthesis of discrete three-dimensional molecules or supramolecular aggregates through the coordination of metals. This field also concerns the chemistry of supramolecular cage compounds constructed through the use of such coordination bonds. To date, there exists a broad variety of supramolecular cage compounds; however, analogous organic cage compounds formed with only covalent bonds are relatively rare. Recent progress in this field can be attributed to important advances, not least the application of dynamic covalent chemistry. This concept makes it possible to start from readily available precursors, and in general allows the synthesis of cage compounds in fewer steps and usually higher yields.

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“…[31] The ionic strength of the experimental solutions was kept at 0.10 Ϯ 0.01 mol dm -3 with NMe 4 NO 3 , and the temperature was maintained at 298.2 Ϯ 0.1 K. Atmospheric CO 2 was excluded from the titration cell during experiments by passing purified nitrogen across the top of the experimental solution.…”

Section: Equipment and Working Conditionsmentioning

confidence: 99%