Laser Induced Crystallization

Fischer, Andrew T.; Pagni, Richard M.; Compton, R. N.; Kondepudi, Dilip K.

doi:10.1016/b978-0-444-53440-8.00008-2

Cited by 13 publications

(15 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the ground-state geometry of the dianion is different from that of the monoanion, an accompanying energy barrier may make the observation of metastable TiAu 12 2– possible. We note that C 60 2– , although higher in energy than C 60 – , was observed due to the repulsive coulomb barrier. , To facilitate comparison with future experiments, we show the IR and Raman spectra in the Figure S2, Supporting Information.…”

Section: Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Rational Design of Stable Dianions and the Concept of Super-Chalcogens

2019

View full text Add to dashboard Cite

Super-atoms are homo/heteroatomic clusters that mimic the chemistry of atoms in the periodic table. While a considerable amount of research over the past three decades has revealed many super-atoms that mimic group I (alkali metals) and group 17 (halogens) elements, little effort has been made to identify super-atoms that mimic the chemistry of chalcogens, i.e., those belonging to group 16 elements. This is particularly important as super-chalcogens can form the building blocks of new materials, just as super-alkalis and super-halogens form a variety of super-salts with unique properties. Using first-principles calculations and various electron counting rules, some of which have been prevalent in chemistry for a century, we provide a route to the rational design of dianions that are stable in the gas phase. And unlike the group 16 atoms, these super-chalcogens can retain the second electron without spontaneous electron emission or fragmentation. A new class of super-chalcogenides with unique properties could be formed with these super-chalcogens as building blocks.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

“…We note that C 60 2− , although higher in energy than C 60 − , was observed due to the repulsive coulomb barrier. 57,58 To facilitate comparison with future experiments, we show the IR and Raman spectra in the Figure S2, Supporting Information.…”

Section: Resultsmentioning

confidence: 99%

Rational Design of Stable Dianions and the Concept of Super-Chalcogens

2019

View full text Add to dashboard Cite

show abstract

“…32 Compton and co-workers described shock-wave crystallization using nanosecond laser pulses (~20 kJ cm -2 ) focused either directly into solution, or onto a thin steel plate floating on top of a solution. [11][12]18 Numerous small crystals were observed throughout the solution, or raining down from the plate, respectively. They saw many more crystals than in the present work, and we attribute this to the use of multiple laser pulses.…”

Section: Discussionmentioning

confidence: 99%

“…[9][10] Nucleation by cavitation or pressure waves can also be caused by nanosecond laser pulses with high energy densities, as studied by Soare et al and Compton and co-workers. [11][12][13] For all methods of LIN, the mechanisms for nucleation are not fully understood, but it is likely that the different methods share common features. 4 Sodium chlorate (NaClO 3 ) is an exemplary enantiomorphic material.…”

Section: Introductionmentioning

confidence: 99%

“…14,17 Mirsaleh-Kohan et al have used focused nanosecond laser pulses to nucleate aqueous supersaturated solutions of simple salts, such as sodium bromate, which is isomorphous with sodium chlorate. [11][12]18 In their experiments, a sequence of nanosecond laser pulses were focused into the solution or onto the surface of a metallic foil in contact with the solution. Numerous small crystals were formed throughout the solution.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pulsed Laser-Induced Nucleation of Sodium Chlorate at High Energy Densities

Barber¹,

Kinney

Alexander³

2019

Crystal Growth & Design

View full text Add to dashboard Cite

We report on a study of laser-induced nucleation (LIN) of sodium chlorate in supersaturated aqueous solutions using focused nanosecond laser pulses at high energy densities (420 kJ cm -2 ). On irradiation with a single laser pulse, optical breakdown was observed in the form of a luminous plasma, and numerous microbubbles were produced. Based on the observations, we estimate the energy threshold for optical breakdown in the solutions to be 70 J cm -2 . Remarkably, even at high energy densities, single laser pulses produced on average only one or two crystals. The mean number of crystals obtained was 1.5 (532 nm) and 1.8 (1064 nm) per sample (3 cm 3 ). The effect of left circularly polarized (LCP) and right circularly polarized (RCP) light on the nucleation of dextrorotatory (d) versus levorotatory (l) enantiomorphs of cubic (phase I) sodium chlorate crystals was investigated. No significant correlation between the helicity of circular polarization and the chirality of enantiomorph was observed. The results are consistent with a mechanism involving nucleation of the achiral monoclinic phase III followed by solid-solid transformation to the chiral cubic phase I of sodium chlorate, although this transformation was not observed directly. The use of single-pulse LIN at high pulse energy densities may be useful in exploration of polymorphs, or in production of single crystals for analysis.

show abstract

Non‐stochastic behavior in sodium chlorate crystallization

et al. 2019

View full text Add to dashboard Cite

NaClO3 is achiral in solution. If crystallization is performed under a static set‐up, it is recognized that the stochastic nucleation probability results in a racemic mixture of the conglomerate. In this paper, we report a reexamination of the crystallization of NaClO3 from static solution in petri dishes that was conducted over a number of years and is based on the count and analysis of several thousand d‐ vs. l‐NaClO3 crystals. Remarkably, instead of an expected nearly 50/50 coin‐tossing situation for the d/l crystal frequency, in most of our experiments a statistically significant bias in favor of d‐ over l‐NaClO3 crystals was found. The experiments also showed that the NaClO3 system was relatively insensitive regarding the intentional addition of a variety of optically active agents. Only in some cases, the persisting d‐bias observed in the unseeded experiments slightly increased upon the presence of such additives. Nevertheless, experiments in plastic petri dishes or in presence of fungal spores were able to reverse this bias. A literature survey shows that mainly d‐directed non‐stochastic behavior in the NaClO3 system has been previously observed in other laboratory settings and by the application of different crystallization techniques. So far, the kind of chiral influence that could be at the origin of the observed bias remains unknown. After the examination of several possible chiral influences of physical, chemical and biological origin, we carefully consider the presence of bio‐contaminants as most likely for the cause of this effect.

show abstract

Laser Induced Crystallization

Cited by 13 publications

References 40 publications

Rational Design of Stable Dianions and the Concept of Super-Chalcogens

Rational Design of Stable Dianions and the Concept of Super-Chalcogens

Pulsed Laser-Induced Nucleation of Sodium Chlorate at High Energy Densities

Non‐stochastic behavior in sodium chlorate crystallization

Contact Info

Product

Resources

About