Self-organized porphyrin arrays on surfaces: the case of hydrophilic side chains and polar surfaces

Rauch, V.; Conradt, Jonas; Takahashi, Mayuko; Kanesato, Masatoshi; Wytko, Jennifer A.; Kikkawa, Yoshihiro; Kalt, H.; Weiss, Jean

doi:10.1142/s108842461350106x

Cited by 7 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To confirm this behavior and to investigate the formation of porphyrin wires on a polar surface, porphyrin 3 28 (Figure 1), with polyethylene glycol (PEG) side chains, was studied. This derivative provides an opportunity to tune the affinity of the building block to the surface and to alter the solvent dependence for higher hierarchical degrees of assembly.…”

Section: Resultsmentioning

confidence: 95%

“…To confirm this behavior and to investigate the formation of porphyrin wires on ap olar surface, porphyrin 3 [28] (Figure 1), with polyethylene glycol (PEG) side chains, was studied. This derivativep rovides an opportunity to tune the affinity of the buildingb lock to the surface and to alter the solventd ependence for higherh ierarchical degrees of assembly.T he most interesting features were observed when drop casting was performed in as olvent, such as THF,t hat had as ignificant affinity for the PEG side chains.…”

Section: Assembly On Hopg or Micamentioning

confidence: 94%

See 1 more Smart Citation

Trapping Nanostructures on Surfaces through Weak Interactions

Rauch

Kikkawa

Koepf

et al. 2015

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

The assembly of imidazole-functionalized phenanthroline-strapped zinc porphyrins (ZnPorphen) with alkyl or polyethylene glycol (PEG) side chains was studied in solution and by AFM after casting on highly oriented pyrolytic graphite (HOPG) or mica. The nature of the solvent and its evaporation time influenced the morphology of the objects observed. On HOPG, short rods of about 100 nm were observed after fast evaporation of solutions of the alkyl derivatives in CHCl3 , THF, or pyridine, whereas islands of aligned rows of longer wires were obtained from methylcyclohexane (MCH). Slow evaporation of MCH led to a three-dimensional assembly. The PEG porphyrin assembled into short wires on HOPG or fibers on mica after slow evaporation of solutions in THF. This study shows the role of surface-molecule interactions in the interfacial assembly of ZnPorphen derivatives and contributes to understanding the parameters that control their noncovalent assembly into molecular wires on a surface.

show abstract

Section: Resultsmentioning

confidence: 95%

Section: Assembly On Hopg or Micamentioning

confidence: 94%

Trapping Nanostructures on Surfaces through Weak Interactions

Rauch

Kikkawa

Koepf

et al. 2015

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…The porphyrinates are capable of forming complexes of various stability with different substrates, such as cations, anions, oxygen, nitric oxide, nitrogen and sulfur-containing organic bases, etc. [ 6 , 7 , 8 , 9 , 10 ], depending on the nature of the central metal cation. The most metalloporphyrin receptors described in the literature are hydrophobic Zn(II)-porphyrins [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ], which form supramolecular complexes with substrates in the organic media (dichloromethane, chloroform, benzene, or toluene).…”

Section: Introductionmentioning

confidence: 99%

Molecular Recognition of Imidazole Derivatives by Co(III)-Porphyrins in Phosphate Buffer (pH = 7.4) and Cetylpyridinium Chloride Containing Solutions

et al. 2021

View full text Add to dashboard Cite

Bymeans of spectrophotometric titration and NMR spectroscopy, the selective binding ability ofthe Co(III)-5,15-bis-(3-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Со(III)Р1) andCo(III)-5,15-bis-(2-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Со(III)Р2) towards imidazole derivatives of various nature (imidazole (L1), metronidazole (L2), and histamine (L3)) in phosphate buffer (pH 7.4) has been studied. It was found that in the case of L2, L3 the binding of the “first” ligand molecule by porphyrinatesCo(III)P1 and Co(III)P2 occurs with the formation of complexes with two binding sites (donor–acceptor bond at the center and hydrogen bond at the periphery of the macrocycle), while the “second” ligand molecule is added to the metalloporphyrin only due to the formation of the donor–acceptor bond at the macrocycle coordination center. The formation of stable complexes with two binding sites has been confirmed by density functional theory method (DFT) quantum chemical calculations and two-dimensional NMR experiments. It was shown that among the studied porphyrinates, Co(III)P2 is more selective towards to L1-L3 ligands, and localization of cobalt porphyrinates in cetylpyridinium chloride (CPC) micelles does not prevent the studied imidazole derivatives reversible binding. The obtained materials can be used to develop effective receptors for recognition, delivery, and prolonged release of drug compounds to the sites of their functioning. Considering that cetylpyridinium chloride is a widely used cationic biocide as a disinfectant, the designed materials may also prove to be effective antimicrobial agents.

show abstract

“…The hierarchical self-assembly in solution was investigated by circular dichroism (CD) measurements, well adapted for chiral porphyrins, 56 while the morphology of the aggregates was investigated by atomic force microscopy (AFM) after casting dilute solutions onto surfaces. 47 For this purpose, different solvents were used to investigate the influence of the polarity of the solvent on the supramolecular organization of the C 3 molecules, as well as the influence of the nature of the surface in the organization over it. In addition, to estimate the role of the central platform on the self-assembly process C 2 symmetric derivative 10 was investigated.…”

Section: Introductionmentioning

confidence: 99%

Large Synthetic Molecule that either Folds or Aggregates through Weak Supramolecular Interactions Determined by Solvent

Oliveras-González

Linares²,

Amabilino

et al. 2019

ACS Omega

View full text Add to dashboard Cite

Weak noncovalent interactions between large disclike molecules in poorly solvating media generally lead to the formation of fibers where the molecules stack atop one another. Here, we show that a particular chiral spacing group between large aromatic moieties, which usually lead to columnar stacks, in this case gives rise to an intramolecularly folded structure in relatively polar solvents, but in very apolar solvents forms finite aggregates. The molecule that displays this behavior has a C 3 symmetric benzene-1,3,5-tris(3,3′-diamido-2,2′-bipyridine) (BTAB) core with three metalloporphyrin units appended to it through short chiral spacers. Quite well-defined chromophore arrangements are evident by circular dichroism (CD) spectroscopy of this compound in solution, where clear exciton coupled bands of porphyrins are observed. In more polar solvents where the molecules are dispersed, a relatively weak CD signal is observed as a result of intramolecular folding, a feature confirmed by molecular modeling. The intramolecular folding was confirmed by measuring the CD of a C 2 symmetric analogue. The C 3 symmetric BTAB cores that would normally be expected to stack in a chiral arrangement in apolar solvents show no indication of CD, suggesting that there is no transfer of chirality through it (although the expected planar conformation of the 2,2′-bipyridine unit is confirmed by NMR spectroscopy). The incorporation of the porphyrins on the 3,3′-diamino-2,2′-bipyridine moiety spaced by a chiral unit leaves the latter incapable of assembling through supramolecular π–π stacking. Rather, modeling indicates that the three metalloporphyrin units interact, thanks to van der Waals interactions, favoring their close interactions over that of the BTAB units. Atomic force microscopy shows that, in contrast to other examples of molecules with the same core, disclike aggregates (rather than fibrillar one dimensional aggregates) are favored by the C 3 symmetric molecule. The closed structures are formed through nondirectional interlocking of porphyrin rings. The chiral spacer between the rigid core and the porphyrin moieties is undoubtedly important in determining the outcome in polar or less polar solvents, as modeling shows that this joint in the molecule has two favored conformations that render the molecule relatively flat or convex.

show abstract

Self-organized porphyrin arrays on surfaces: the case of hydrophilic side chains and polar surfaces

Cited by 7 publications

References 10 publications

Trapping Nanostructures on Surfaces through Weak Interactions

Trapping Nanostructures on Surfaces through Weak Interactions

Molecular Recognition of Imidazole Derivatives by Co(III)-Porphyrins in Phosphate Buffer (pH = 7.4) and Cetylpyridinium Chloride Containing Solutions

Large Synthetic Molecule that either Folds or Aggregates through Weak Supramolecular Interactions Determined by Solvent

Contact Info

Product

Resources

About