Solution crystal growth of urea and derivatives for nonlinear optical applications

Zeng, L.; Zha, M.; Ardoino, M.; Franzosi, P.; Zanotti, L.; Zuccalli, G.; Paorici, C.

doi:10.1016/0022-0248(96)00145-5

Cited by 20 publications

(11 citation statements)

References 8 publications

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“…We want to explain the influence of solvent polarity (activity) on the character of aggregation. We started with a study of the symmetric N,N′-dimethyl-(1) and diethylurea (2) discussed by Jadżyn et al 9,10 but also symmetric N,N′-dipropylurea (3) and N,N′-dibutylurea (4) as well as asymmetric N,N-diethylurea (5). We aim to explain the influence of symmetry on aggregation as well as the effects of the length of chains.…”

Section: Introductionmentioning

confidence: 99%

“…2 Crystals of the alkyl derivatives of urea are promising materials for nonlinear optics. 3 More recent studies have described the highly viscoelastic properties of bis-urea moieties in toluene solutions, resulting from the formation of cylindrical wires due to aggregation by hydrogen bonding. 4 Alkyl derivatives of urea have found widespread applications in the pharmaceutical industry because they influence many biological functions in organisms, including antitumor activity.…”

Section: Introductionmentioning

confidence: 99%

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Structure of Aggregates of Dialkyl Urea Derivatives in Solutions

2010

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Combined IR spectroscopy, dipole moment, and average molecular weight measurements and DFT calculations on the self-aggregation of N,N'- and N,N-dialkylureas in solvents of different polarities were performed. It was found that, to acquire a better understanding of the mechanisms of associations, the simultaneous use of all of these methods is required. It was found that symmetric dialkyl derivatives of urea associate much more strongly, giving in CCl(4) even a 12-fold mass of monomers, in contrast to asymmetric ones, where the average molecular weight reaches only a 2-fold mass of monomers. The very strong influence of solvents was discovered. The aggregation is much weaker in more polar chloroform and 1,2-dichloroethane leading to only a 2-fold increase in the average molecular weight. A strong influence of the symmetry of dialkylurea molecules was also found. Dipole moments of symmetric N,N'-dialkylurea increase with concentration, suggesting a rather linear arrangement of vectors in an aggregate. For asymmetric N,N-derivatives dipole moments decrease with concentration. DFT calculations were used to predict the form of aggregation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structure of Aggregates of Dialkyl Urea Derivatives in Solutions

2010

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“…Such attempts involve the doping of other organic and inorganic NLO materials with urea. Many such efforts have become successful [12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 98%

Crystal growth and characterization of a new NLO crystal: Urea 2-furoic acid

Jagadeesh

Kumar

Kumari

2015

Optik

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“…The powder second harmonic generation (SHG) of urea is 2.5 times that of potassium dihydrogen phosphate (KDP) crystal powder and the laser damage threshold is 3×10 9 Wcm -2 at 532 nm for 10 ns pulse. It is reported in literature that urea doped organic derivatives can yield improved NLO properties 8 . Due to the this, urea was used as a dopant in L-cysteine hydrochloride monohydrate.…”

Section: Introductionmentioning

confidence: 99%