22 research outputs found
Azobenzola kodola poliestera tipa dendrimēru diverģentā sintēze
Poliestera tipa dendrimēri sintezēti līdz trešajai ģenerācijai, par kodola molekulu izmantojot 4-N,N-bis(2-hidroksietil)amino-3-metoksi-4’-nitroazobenzolu un zarojumu veidojot no 3,5-bis(2-(tetrahidro-2H-piran-2-iloksi)etoksi)benzoskābes. Dendrimēra augšanas solis tika veikts ar dicikloheksilkarbodiimīdu absolūta CH2Cl2 šķīdumā, kā katalizatoru izmantojot 4-N,N-dimetilaminopiridīnu. Aizsarggrupu noņemšana veikta EtOH/CH2Cl2 šķīdumā ar HCl. Abi soļi dod labus iznākumus, kuri samazinās, pieaugot dendrimēra ģenerācijai, jo ir lielāka nepilnīgu reakciju iespējamība, palielinoties reaģētspējīgo grupu skaitam
Quantification of Push-Pull Character of Azo Dyes and a Basis for Their Evaluation as Potential Nonlinear Optical Materials
The push–pull character of a series of para-phenyl substituted isophorone chromophores has been quantified by the 13C chemical shift difference of the three conjugated partial Cdouble bond; length as m-dashC double bonds and the quotient of the occupations of both the bonding and anti-bonding orbitals of these Cdouble bond; length as m-dashC double bonds as well. The correlations of the two push–pull quantifying parameters, and to the corresponding bond lengths, strongly recommend View the MathML sourceπCC∗/πCdouble bond; length as m-dashC as the general parameter to estimate charge alternation and as a very useful indication of the molecular hyperpolarizabilities for NLO application of the compounds studied
Synthesis of Soluble Derivatives of Fullerene C60
Looking for the new approaches of increasing of reactivity and solubility (especially in polar solvents) of fullerene derivatives, the synthesis of bistriethylammonium salt of fullerene C60 biscarboxylic acid has performed
Synthesis of Pyridinium Betaine Azo Chromophores
New chromophores have been synthesized and investigated containing as acceptor a quaternized pyridine unit with mobile bromine in the structure conjugated with two donor units - the indan-1,3-dione anion and the dihydroxyethylamino group through a π-conjugated spacer
Novel Azobenzene Precursors for Electro Optical Active Polyuretanes: Synthesis, Quantum Chemical and NLO Characterization
Six new derivatives of 2-{(2-hydroxyethyl)-[4-(4-nitrophenylazo)phenyl]amino}ethanol and two – of 2-{(2-hydroxyethyl)-[4-(5-nitropiridin-2-ylazo)phenyl]amino}ethanol were synthesized by azocoupling reaction for future polyurethane obtaining. Hyperpolarizability βff and dipole moment μg were calculated using HyperChem software package. Second order non linear properties (NLO) of doped PMMA films azochromophores were characterized by d15, d31 and d33 coefficients that were obtained by SHG experiments for comparing NLO efficiency of chromophores.