Polymorphism and crystal-crystal transformations of the highly optically nonlinear organic compound α-[(4′-methoxyphenyl)methylene]-4-nitro-benzeneacetonitrile

Oliver, S. N.; Pantelis, P.; Dunn, Peter L.

doi:10.1063/1.103288

Cited by 22 publications

(17 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly to many reported stilbene derivatives, 20,21,34,35 the 2chloro-3,4-dimethoxy-4 0 -nitrostilbene compound 1a shows polymorphism by crystallization in both centrosymmetric (P2 1 /c, 1aÁ centro) and non-centrosymmetric (P2 1 , 1aÁnon-centro) space groups (Fig. 1, cf.…”

Section: Single-crystal X-ray Structures Of Stilbene Derivativessupporting

confidence: 76%

Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives

et al. 2021

View full text Add to dashboard Cite

show abstract

Section: Single-crystal X-ray Structures Of Stilbene Derivativessupporting

confidence: 76%

Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The bulk crystalline phases of such crystals have three possible polymorphic forms, two being noncentrosymmetric with a very similar unit-cell crystal geometry (forms (a) and (b)) [10,11,12]. The preparation of the organic nanocrystals in sol-gel glasses relies on the control of the nucleation and growth kinetics of the dye confined in the pores of the gel [10].…”

mentioning

confidence: 99%

In SituDiagnostics of the Crystalline Nature of Single Organic Nanocrystals by Nonlinear Microscopy

Brasselet¹,

Floc’h²,

Treussart³

et al. 2004

Phys. Rev. Lett.

133

156

View full text Add to dashboard Cite

We elucidate the crystalline nature and the three-dimensional orientation of isolated organic nanocrystals embedded in a sol-gel matrix, using a polarized nonlinear microscopy technique that combines two-photon fluorescence and second harmonic generation. This technique allows the distinction between mono-crystalline structures and nano-scale poly-crystalline aggregates responsible for incoherent second harmonic signals.PACS numbers: 78.67. Bf, 61.82.Rx The optical properties of nanoparticles have recently attracted much attention. In addition to metallic and semiconductor nanoparticles which are now used as biomarkers and as the building blocks of nanostructured materials [1], their organic counterparts constitute an interesting alternative. Advances in molecular engineering have enabled the design of molecular structures of various resonances and symmetries with optimized one-and two-photon absorption cross sections [2], or combining different optical properties such as luminescence and second harmonic generation (SHG) [3]. In addition, macroscopic molecular arrangements have been optimized using the tensorial oriented gas model [4], which predicts that an enhancement of the SHG efficiency is expected from the non-centrosymmetric crystalline arrangement of efficient nonlinear molecules. Molecular nanocrystals can be therefore envisioned as a new class of multi-functional nano-scale materials. In the case of organic nanocrystals however, the traditional crystalline characterization techniques have raised many practical barriers due to their low concentration and fragility. Consequently, the elucidation of their crystalline nature has been so far indirect or averaged over a large number of nanocrystals [5].In this letter, we show that two-photon nonlinear microscopy permits in-situ characterization of isolated organic nanocrystals grown in an amorphous sol-gel matrix. The diagnostic is based on polarization resolved two-photon excited fluorescence (TPF) and SHG. TPF is an incoherent process allowed in centrosymmetric media, which exhibits a specific anisotropy depending on the medium symmetry. On the other hand, SHG is the signature of a crystalline non-centrosymmetric phase in the sample, with a sensitivity down to the nanometric scale [6,7]. We show that the polarization analysis of both TPF and SHG from nanocrystals allows the unambiguous discrimination between isolated mono-crystalline and poly-crystalline systems. Moreover, once a nanocrystal has been identified as mono-crystalline, a detailed model for both TPF and SHG polarization responses accounting for the unit-cell symmetry allows the determination of its three-dimensional orientation within the host matrix.The organic nanocrystals that we investigate are based upon the α-((4'-methoxyphenyl)methylene)-4-nitro-benzene-acetonitrile) molecule (CMONS), which exhibits efficient luminescence and quadratic nonlinearity under two-photon excitation [8,9,10]. The bulk crystalline phases of such crystals have three possible polymorphic forms, two being noncen...

show abstract

“…2) [4]. In this work, we have characterized organic aggregates of α-[(4 -methoxyphenyl) methylene]-4-nitro-benzene-acetonitrile (CMONS) [23] and stilbene 3 [24], which were selected for their luminescent and optical limiting properties, respectively. The concentration of the organic particles depends on their solu-bility and on the nature of the matrix.…”

Section: Organic Nanocrystals Grown In Bulk Gel-glassesmentioning

confidence: 99%

“…This molar ratio, directly related to the viscosity of the initial sol, is adjusted to achieve the good nanocrystallization conditions and the preparation of high quality coatings [5]. As for the preparation of bulk nanocomposite samples, in order to demonstrate the validity and the flexibility of this nanocrystallisation process, we have grown nanocrystals of several organic phases such as DEANST and CMONS, chosen for their luminescent and non-linear optical properties [20,23], NPP for its high quadratic NLO efficiency [25], and pyrido-spiropyran (PSP) for photochromism properties [26]. We have also grown other types of nanocrystals, such as naphthalene, to demonstrate the gain in stability of the organic phase through the nanocrystallisation process, as pure naphthalene crystals exhibit a high sublimation rate.…”

Section: Organic Nanocrystals Grown In Sol-gel Thin Filmsmentioning

confidence: 99%

Organic nanocrystals grown in sol-gel matrices: new hybrid organic-inorganic materials for optics

Monnier

Dubuisson

Sanz

et al. 2008

Res. Chem. Intermed.

View full text Add to dashboard Cite

We have developed a simple and generic preparation of stable organic nanocrystals grown in gel-glass matrices. The synthesis of these hybrid organic-inorganic materials is based on the confined nucleation and growth of organic phases in the pores of dense gels. For bulk nanocomposite samples, narrow size distributions of particles (10-20 nm in diameter) are obtained. We have extended this method to the preparation of organic nanocrystals embedded in sol-gel thin films prepared by spin-coating. For all these nanocomposite materials, we have significantly increased the dye stability and obtained promising optical properties: luminescence, non-linear optical properties or photochromism. Moreover, we have also demonstrated basic working principles of a new type of fluorescent nanosensor through the preparation of organic luminescent nanocrystals grown in silicate films.

show abstract

Polymorphism and crystal-crystal transformations of the highly optically nonlinear organic compound α-[(4′-methoxyphenyl)methylene]-4-nitro-benzeneacetonitrile

Cited by 22 publications

References 8 publications

Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives

Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives

In SituDiagnostics of the Crystalline Nature of Single Organic Nanocrystals by Nonlinear Microscopy

Organic nanocrystals grown in sol-gel matrices: new hybrid organic-inorganic materials for optics

Contact Info

Product

Resources

About