RESUMO
Paper reports the measured optical absorption and fluorescence spectra of 4-(2-chlorophenyl)-7-methyl-1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline (MCPDPPQ), as well as 6-methyl-1,3-diphenyl-3H-indeno[1,2,3-de]pyrazolo[3,4-b]quinoline (MDPIPQ) and 9-methyl-6-phenyl-6H-5,6,7-triazadibenzo[f,h]naphtho[3,2,1-cd]azulene (MPTNA) representing cyclized five- or seven-membered regioisomeric products of MCPDPPQ, respectively. The spectra has been recorded in solvents of different polarity and compared with the results of quantum chemical calculations performed by means of the semiempirical method PM3 in combination with molecular dynamics (MD) simulations. Cyclization of MCPDPPQ into MDPIPQ or MPTNA is accompanied by a significant red shift of the first optical absorption and fluorescence bands. While the solvent polarity rises all the dyes exhibit the blue shift of the first absorption band and the red shift of the fluorescence band. These trends have been reproduced within the semiempirical calculations in combination with the Lippert-Mataga dielectric polarization model and explained by specific orientations of the dipole moments in the ground and excited states. All dyes may be considered as candidates for the luminescent or electroluminescent applications. Depending on solvent polarity they emit light in the green-yellow range of the visible spectra.
Assuntos
Compostos Aza/química , Azulenos/química , Corantes/química , Fluorenos/química , Teoria Quântica , Compostos Aza/síntese química , Azulenos/síntese química , Fluorenos/síntese química , Cinética , Conformação Molecular , Fenômenos Ópticos , Quinolinas/síntese química , Quinolinas/química , Soluções , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , TermodinâmicaRESUMO
A series of methoxy (MO) and carboethoxy (CE) derivatives of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline ([DPPQ]) are characterized by spectroscopic methods. All dyes show the photoluminescent spectra which are highly solvatochromic. In the case of 6MO[DPPQ] and 6CE[DPPQ] the emission bands are broad and shifted to the red with increasing of solvent polarity whereas the dyes 6MO1pMO[DPPQ] and 6MO13pMO[DPPQ] exhibit a reverse solvatochromism. The large difference between the excited- and state-dipole moments indicates a strong electron transfer effects in all dyes. The EL spectra are obtained for the fabricated OLEDs with a general structure of EL device ITO/PVK:6X[DPPQ]/Ca/Al. The blue emission originating from PVK host matrix appears to be quenched in EL spectra of doped PVK matrix giving rise to emission in blue, blue-green or green spectral regions. The obtained results demonstrate that a series of newly synthesized methoxy and carboethoxy [DPPQ]-derivatives may be considered as promising materials for electroluminescent applications.
Assuntos
Eletricidade , Luminescência , Pirazóis/química , Quinolinas/química , Conformação Molecular , Solventes , Análise EspectralRESUMO
Paper deals with experimental investigations and quantum chemical calculations of the optical absorption spectra of methoxy and carboethoxy 1,3-diphenyl derivatives of the pyrazoloquinoline ([PQ]): 6-methoxy-1,3-dyphenil-[PQ], 6-methoxy-1,3-(p-methoxyphenyl)-[PQ], 6-methoxy-1-(p-methoxyphenyl)-[PQ] and 6-carboethoxy-1,3-diphenyl-[PQ]. The quantum chemical calculations are performed by means of the semiempirical quantum chemical methods (AM1 or PM3) applied to: (a) the equilibrium molecular conformation in vacuo (T=0 K); (b) the molecular dynamic (MD) trajectory (T=300 K) which includes the dynamics of a certain molecular fragment (moiety) only (fragmental MD simulations); or (c) the MD trajectory obtained for most general case within the total MD simulations at T=300 K. The results of these calculations are compared with the measured spectra of the optical absorption. The quantum chemical simulations show that the dynamics of the methoxy or carboethoxy groups practically does not influence the absorption spectrum whereas the strongest its modification (300Assuntos
Compostos de Bifenilo/química
, Pirazóis/química
, Quinolinas/química
, Absorção
, Simulação por Computador
, Modelos Químicos
, Modelos Moleculares
, Conformação Molecular
, Estrutura Molecular
, Teoria Quântica
, Espectrofotometria
RESUMO
STUDY DESIGN: A masked, single-factor, posttest-only control group design. OBJECTIVE: To explore the relationship between reported oral contraceptive use and peripheral joint laxity. BACKGROUND: Studies have found an association between increased ligamentous laxity and changes in serum levels of hormones such as estrogen, progesterone, and relaxin. Two of these hormones, estrogen and progesterone, are present in most oral contraceptives. Oral contraceptive users, therefore, provide a population for studying the effects of these hormones on the degree of ligamentous laxity. METHODS AND MEASURES: Fifty-five women between the ages of 20 and 25 years participated in this study. Thirty users of oral contraceptives were a test group and 25 nonusers of oral contraceptives were controls. The KT-1000 Arthrometer was used to measure passive anterior translation of the tibia in relation to the femur in both knees. Passive abduction and adduction of the proximal interphalangeal (PIP) joint of the second digit of the nondominant hand and distal interphalangeal (DIP) joint hyperextension of the fifth digit of the nondominant hand were measured using a goniometer. A subjective measurement of passive second PIP joint motion was also assessed and a value of minimum, moderate, or maximum laxity was assigned. Independent sample t tests were performed to compare the measurements of the oral contraceptive user and nonuser groups for each joint. A chi-square test compared the subjective PIP joint data between the 2 groups. RESULTS: No significant differences in laxity measurements at the knee or hand were found between the 2 groups. Average knee laxity varied between 5.7-7.9 mm of anterior displacement for both groups. Average PIP abduction and adduction varied between 6.5-6.7 degrees for both groups and DIP hyperextension was 28.6-29.9 degrees. CONCLUSIONS: Results of this study indicate that self-reported oral contraceptive use was not associated with peripheral joint laxity.