Tunable solid state fluorescence behavior of a methoxy substituted oligo(phenyleneethynylene): influence of cooling rate and surface crystallization

Gupta, Ritu; Thomas, Reji

doi:10.1039/c2jm31903a

Cited by 7 publications

(6 citation statements)

References 40 publications

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“…Such polymorphic behavior has been previously reported for a number of donor−acceptor substituted π-conjugated systems. 1c, 17 The inset in Figure 2a shows the difference spectrum obtained by subtracting normalized absorption spectra of MPT1 from that of MPT2. Significant enhancement in the relative intensity of absorption in the long wavelength region, namely 375 nm for MPT2, is suggestive of higher content of the J-aggregates compared to that for MPT1.…”

Section: Resultsmentioning

confidence: 99%

Optical Investigation of Self-Aggregation of a Tetrazole-Substituted Diphenylacetylene Derivative: Steady and Excited State Dynamics in Solid and Solution State

2013

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Slow crystallization and fast precipitation of a tetrazole-substituted diphenylacetylene derivative (MPT) led to formation of solids with significantly different photoluminescence efficiencies of 0.06 and 0.33, respectively. A detailed study of the photophysical properties of solutions of MPT as a function of concentration and temperature indicated that the extent of formation of J-and H-aggregates played a significant role in determining the luminescence properties of these materials. Timeresolved emission spectroscopy showed that the lifetime of emission arising from the aggregated species was significantly higher than that of the monomer species. The long-lived emission might be due to the formation of excimer arising from the excitation of ground state J-and H-aggregates. The higher quantum yield of fluorescence in the solids obtained by fast precipitation could be attributed to the presence of increased amounts of J-aggregates similar to that observed in highly concentrated solutions (≥ 4.2 × 10 −4 M). The photophysical studies of MPT in various concentrations indicate that J-aggregates are significantly more fluorescent than the H-aggregates. Transient absorption spectra measured by nanosecond laser flash photolysis indicated the formation of a triplet excited state with an absorption maximum of ∼490 nm and a quantum yield of 0.61.

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Section: Resultsmentioning

confidence: 99%

Optical Investigation of Self-Aggregation of a Tetrazole-Substituted Diphenylacetylene Derivative: Steady and Excited State Dynamics in Solid and Solution State

2013

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“…Kulkarni and co-workers crystallized a series of OPEs using the slow evaporation method whereby saturated OPE solutions in toluene were evaporated at room temperature to obtain single crystals for X-ray diffraction. 57,58 OPE-1 and OPE-2 were crystallized by the solvent evaporation method. 12 OPE-3–5 were crystallized by diffusion of poor solvent/precipitant (acetone) into a THF solution of OPE.…”

Section: Crystallization Procedures For Ope Based Supramolecular Asse...mentioning

confidence: 99%

“…Surprisingly, reports of crystal structures of OPEs are still few. [53][54][55][56][57][58][59] A particular reason cannot be inferred that has led to this lacuna. One reason might be that growing single crystals of these oligomers is not easy and it involves a careful examination of their solubility in different solvents.…”

Section: Ope Derived Supramolecular Networkmentioning

confidence: 99%

“…Kulkarni and co-workers also synthesized OPEs with side chains varying from methyl to hexyl and studied the effect of packing on emission properties. 57,58 Interestingly, they found that all the OPEs exhibited similar fluorescence maxima in solution; however, their solid state spectral pattern varied. There was no direct correlation between the increase in alkyl chain length and the shift in fluorescence maxima.…”

Section: Crystallization Procedures For Ope Based Supramolecular Asse...mentioning

confidence: 99%

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Self-assembled organic and hybrid materials derived from oligo-(p-phenyleneethynylenes)

Roy

Maji

2022

Chem. Commun.

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“…In spite of the vast potential of OPEs, only a tiny progress has been made in the structural understanding behind the occurrence of such properties. − Recently, Sharber et. al.…”

Section: Introductionmentioning

confidence: 99%

Tunable Physical States and Optical Properties of Bola-Amphiphilic Oligo-(p-phenyleneethynylene)-Based Supramolecular Networks Assisted by Functional Group Modulation

et al. 2018

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Structural understanding and correlation of physical properties of supramolecular networks can lead to improved design strategies for advanced optoelectronic materials. Herein, we demonstrate via single-crystal X-ray diffraction (SCXRD) analysis how end groups (ester and acid) of bola-amphiphilic oligo-(pphenyleneethynylenes) (OPEs) lead to different supramolecular network formations and also generate selective polymorphism and mechanochromic luminescence in OPE-C gly -A and OPE-C gly -E, respectively. OPE-C gly -E and OPE-C gly -A have the same π-conjugated backbones with bistriethyleneglycol side chains, only differing in possessing end-capped ester and acid groups, respectively. OPE-C gly -E has a less densely packed structure than OPE-C gly -A. This leads to exclusive mechanochromic behavior in OPE-C gly -E, whereas OPE-C gly -A generates reversible polymorphic structures which are not present in OPE-C gly -E. Density functional theoretical calculations reveal that breakage of weak supramolecular interactions in OPE-C gly -E leads to the hypsochromic mechanochromic luminescence. Interestingly, both OPE-C gly -E and OPE-C gly -A crystals reversibly melt into an isotropic phase at 90 and 180 °C, respectively, and recrystallize upon cooling. This difference in melting temperature is due to the variance in molecular packing in both compounds. Thus, this work gives a structural perspective toward the control of physical states and optical properties of OPEs for a better design of bola-amphiphilic supramolecular networks for advanced opto-electronics.

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Tunable solid state fluorescence behavior of a methoxy substituted oligo(phenyleneethynylene): influence of cooling rate and surface crystallization

Cited by 7 publications

References 40 publications

Optical Investigation of Self-Aggregation of a Tetrazole-Substituted Diphenylacetylene Derivative: Steady and Excited State Dynamics in Solid and Solution State

Optical Investigation of Self-Aggregation of a Tetrazole-Substituted Diphenylacetylene Derivative: Steady and Excited State Dynamics in Solid and Solution State

Self-assembled organic and hybrid materials derived from oligo-(p-phenyleneethynylenes)

Tunable Physical States and Optical Properties of Bola-Amphiphilic Oligo-(p-phenyleneethynylene)-Based Supramolecular Networks Assisted by Functional Group Modulation

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