Adventures in molecular recognition. The ins and outs of templating

Sanders, Jeremy K. M.

doi:10.1351/pac200072122265

Cited by 91 publications

(47 citation statements)

References 23 publications

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“…nostic 1 H NMR resonances for the cyclic oligomers 27 ± 36 are shown in Tables 1 ± 4 (500 MHz, CDCl 3 , 298 K). …”

Section: Cyclic Sn Porphyrin Oligomersmentioning

confidence: 99%

“…[12] A solution of SnCl 2 porphyrin was stirred with alumina and subsequently filtered or passed through a short column of alumina. In the presence of alumina, ethanol and Sn(OH) 2 , porphyrins form SnCl 2 porphyrin ethoxide complexes; highfield 1 H NMR resonances with characteristic ethyl multiplets in addition to meso-and b-pyrrole signals indicate tin-bound ethoxide. To prevent contamination by alcohols, which tend to coordinate to the Sn site, all chloroform was filtered through basic alumina (activity V) prior to use.…”

Section: Introductionmentioning

confidence: 99%

“…To monitor the hydrolysis of SnCl 2 porphyrins, an aliquot of the reaction mixture was removed and analysed by 1 H NMR spectroscopy; small shifts in the resonances of the propionate and pyrrole methyl protons of 6, and an upfield displacement of the meso resonance (or b-pyrrole resonance of TPP) were indicative of hydrolysis. In mixtures of SnCl 2 , SnCl(OH) and Sn(OH) 2 porphyrins, the meso (or b-pyrrole) resonances attributable to the three porphyrin species were resolved in a very confined region of the spectrum ($ 9.2 ppm for the bpyrrole or $ 10.1 ppm for the meso protons), while the SnÀOH resonance of Sn(OH) 2 porphyrins in [D]chloroform were broad and not diagnostic of the progress of the reaction.…”

Section: Introductionmentioning

confidence: 99%

“…The large carboxylateresonance shift that occurs when carboxylate groups bind to Sn porphyrins, and the fact that the resulting complexes are in slow exchange, render Sn porphyrin carboxylate complexes suitable for a computational analysis that calculates the shift (Dd) of ligand 1 H NMR resonances on binding to porphyrins. [16] In the model we applied, the porphyrin ring current was parameterised for a particular class of metalloporphyrin, and all the atoms of the complex were defined in three-dimensional space.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers

Hawley

Bampos

Sanders

2003

Chemistry A European J

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Most of the porphyrin-recognition chemistry we have investigated previously has centred on kinetically labile metal-ligand interactions, such as Z-N and Ru-N. Our interest in the broader scope of molecular recognition required a metal with the ability to specifically recognise non-nitrogen-based ligands, with a significantly different binding interaction to distinguish it from nitrogen-based analogues. In this report we describe interactions of Sn(IV) porphyrins that bind oxygen-based ligands and for which the Sn(IV)bond;O bond is in slow exchange on the NMR timescale. A series of carboxylate complexes is employed to highlight the structural/geometric features of porphyrin monomers and cyclic oligomers. Where more than one porphyrin unit is present in a molecular scaffold, we report the effect of carboxylate binding on the complex when the two porphyrins contain different metals (typically Sn(IV) and Zn(II)). The unexpected spectroscopic and structural properties of the Sn(2)(9-anthroic acid)porphyrin dimer are also reported.

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“…nostic 1 H NMR resonances for the cyclic oligomers 27 ± 36 are shown in Tables 1 ± 4 (500 MHz, CDCl 3 , 298 K). …”

Section: Cyclic Sn Porphyrin Oligomersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers

Hawley

Bampos

Sanders

2003

Chemistry A European J

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“…Sanders e colaboradores [68][69][70][71][72][73] prepararam supermoléculas cíclicas ligando 5,15-fenilporfirinas por meio de pontes Pt acetileno, butadiinos ou cadeias superiores. Numa série de trabalhos, os autores utilizaram 4,4´-bipiridina, tris-4-piridiltriazina e meso-tetra(4-piridil)porfirina como moldes ("templates") ( Fig.1.4.2).…”

Section: Fig141unclassified

Interfaces e dispositivos baseados em porfirinas supramoleculares

Winnischofer¹

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A Ring-in-Ring Complex

et al. 2002

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Over the past two decades a vast array of interlocked and intertwined molecular compounds-specifically, catenanes, rotaxanes, and knots [1] -have been assembled using supramolecular assistance (templation [2] ) as the key element in their synthesis [3] under either kinetic [4] or thermodynamic [5] control. Although these synthetic protocols have been implemented more recently for the construction of more intricate variants, such as oligocatenanes, [6] molecular necklaces, [7] and cyclic daisy chains [8] to name but a few, the topological challenge of the de novo synthesis of Borromean ring compounds [9] still presents a considerable hurdle to be overcome. Our way of addressing this challenge is to employ recognition motifs to create initially stable ring-in-ring superstructures [10] which could serve as templates for subsequent catenation. Here, we report 1) the design and noncovalent synthesis of a prototype, mutually orthogonal, partially preorganized, ring-in-ring complex, together with 2) the solid-state characterization of the 1:1 complex in the context of the X-ray crystal structures of its two separate ring components, and 3) the solution-state behavior of the 1:1 complex.Previously, we have shown [11] that bisparaphenylene[34]crown-10 (BPP34C10) can encircle two dibenzylammonium (DBA ) ions simultaneously by locating the two NH 2 centers 6.9 ä apart in the polyether loops of BPP34C10 and relying upon N ÀH ¥¥¥ O hydrogen bonds to form a stable 1:2 (DBA & BPP34C10 ' DBA ) complex. Thus, it seemed not unreasonable to us that BPP34C10 might also be able to complex (Figure 1) with a suitably proportioned dicationic Figure 1. Employing precedent in the design and synthesis of a proposed 1:1 complex formed between BPP34C10 and 1-2 H 2 , together with an overlaid set of 70 co-conformations of BPP34C10 ¥ 1-2 H 2 sampled from the last 70 ps of a 100-ps MD experiment. macrocycle containing two NH 2 centers. After inspection of the solid-state superstructure [11] of the 1:2 complex formed between BPP34C10 and DBA , and construction of CPK space-filling molecular models, we concluded that the macrocycle 1-2 H 2 was a suitable candidate for further investigation. Our intuition was given a considerable boost by the results of the molecular dynamics (MD) calculations. [12] They predicted the existence of a stable co-conformation [13] in which the BPP34C10 ring encircles the dicationic macrocycle, such that the polyether loops surround the NH 2 centers, namely, the 1:1 (BPP34C10 ' 1-2 H 2 ) complex (illustrated in Figure 1) might constitute a discrete supermolecule.The synthesis (Scheme 1) of the dicationic macrocycle 1-2 H ¥ 2 PF 6 was achieved by employing a bis-Wittig reaction in the key cyclization step. The bisphosphonium salt [14] 2-H ¥ 3 PF 6 was protected (Boc 2 O/Et 3 N/MeOH) to give 3 ¥ 2 PF 6[15] M.Abstracts of Papers, Part 1, 222nd National Meeting of the American Chemical Society (Chicago, IL) 2001, MEDI 307.[16] Female Rhesus monkeys (body weight 4.0 ± 7.0 kg) were sedated with 10 mg kg À1 of ketamine ...

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Adventures in molecular recognition. The ins and outs of templating

Cited by 91 publications

References 23 publications

Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers

Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers

Interfaces e dispositivos baseados em porfirinas supramoleculares

A Ring-in-Ring Complex

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Adventures in molecular recognition. The ins and outs of templating

Cited by 91 publications

References 23 publications

Synthesis and Characterization of Carboxylate Complexes of SnIV Porphyrin Monomers and Oligomers

Synthesis and Characterization of Carboxylate Complexes of SnIV Porphyrin Monomers and Oligomers

Interfaces e dispositivos baseados em porfirinas supramoleculares

A Ring-in-Ring Complex

Contact Info

Product

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Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers

Synthesis and Characterization of Carboxylate Complexes of Sn^IV Porphyrin Monomers and Oligomers