A5016265534- Supramolecular Self-Assembly in Materials
- Electron Spin Resonance Studies
- Crystallography and molecular interactions
- Crystallization and Solubility Studies
- Solid-state spectroscopy and crystallography
- X-ray Diffraction in Crystallography
- Lipid Membrane Structure and Behavior
- Crystal structures of chemical compounds
- Fluorine in Organic Chemistry
- Photochemistry and Electron Transfer Studies
- Synthesis and Reactions of Organic Compounds
- Chemical Synthesis and Analysis
- Biochemical and Molecular Research
- Molecular spectroscopy and chirality
- Synthesis and Characterization of Heterocyclic Compounds
- Photopolymerization techniques and applications
- HIV/AIDS drug development and treatment
- Glycosylation and Glycoproteins Research
- Advanced NMR Techniques and Applications
- Glass properties and applications
- Liquid Crystal Research Advancements
- Carbohydrate Chemistry and Synthesis
- Magnetic and Electromagnetic Effects
- Microbial Inactivation Methods
- Radiation Effects and Dosimetry
University of Zagreb
2017-2018
Polytechnic Pula
2018
Rudjer Boskovic Institute
2006-2017
Stable gels can be obtained from water and organic solvents with bis(amino acid) oxalyl amides. In aqueous systems lipophilic interactions lateral hydrogen bonding dominate their self-organisation into gel fibres as depicted here. organic-solvent intermolecular governs the self-organisation. Gels were studied by 1H NMR, FTIR, TEM, SEM single crystal X-ray analysis. Bis(LeuOH) (1 a), bis(ValOH) (2 a) bis(PhgOH) (5 (Phg denotes (R)-phenylglycine) amides are efficient low molecular weight...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTBis(PheOH) Maleic Acid Amide−Fumaric Amide Photoizomerization Induces Microsphere-to-Gel Fiber Morphological Transition: The Photoinduced Gelation SystemLeo Frkanec, Milan Jokić, Janja Makarević, Kristina Wolsperger, and Mladen ŽinićView Author Information Laboratory of Supramolecular Nucleoside Chemistry NMR Center, Department Biochemistry, Rudjer Bošković Institute, 10000 Zagreb, Bijenićka 54, Croatia Cite this: J. Am. Chem. Soc. 2002, 124,...
Abstract Four new chiral bis(amino alcohol)oxalamides ( 1 – 4 : amino alcohol=leucinol, valinol, phenylglycinol, and phenylalaninol, respectively) have been prepared as low‐molecular‐weight organic gelators. Their gelation properties towards various solvents mixtures were determined these then compared to related acid) oxalamide Spectroscopic (FTIR, H NMR) X‐ray diffraction studies revealed that the primary organization motif of S , )‐ racemate rac ‐ ) in lipophilic involved formation...
Bis(S)-leucine (1) and bis-(R)-α-phenylglycine (2) oxalyl amides are discovered to be efficient small organic gelling agents capable of gelating water while their stereoisomers meso-1 meso-2 as well racemates found non-gelling poorly gelling, respectively; IR, fluorescence emission spectroscopy TEM used study assemblies (S,S)-1 (R,R)-2 in gels.
Some bis (amino acid) oxalamide gelators form common thermo-reversible gels with various organic solvents but also of exceptional thermal stability some medium and low polarity; the latter can be heated up to 50 degrees C higher temperatures than bp solvent without apparent gel-to-sol transition.
The electron spin-lattice relaxation of 2,2,6,6-tetramethyl-1-piperidine-1-oxyl and 4-oxo-2,2,6,6-tetramethyl-1-piperidine-1-oxyl was measured at temperatures between 5 80 K in crystalline glassy ethanol using $X$-band paramagnetic resonance spectroscopy. experimental data the lowest studied were explained terms electron-nuclear dipolar interaction center localized excitations, whereas higher low-frequency vibrational modes from host matrix Raman processes should be considered. strong impact...
In this work we report on gelation properties, self-assembly motifs, chirality effects and morphological characteristics of gels formed by chiral retro-dipeptidic gelators in the form terminal diacids (1a-5a) their dimethyl ester (1b-5b) dicarboxamide (1c-5c) derivatives. Terminal free acid retro-dipeptides (S,S)-bis(LeuLeu) 1a, (S,S)-bis(PhgPhg) 3a (S,S)-bis(PhePhe) 5a showed moderate to excellent highly polar water/DMSO water/DMF solvent mixtures. Retro-peptides incorporating different...
$X$-band electron paramagnetic resonance spectroscopy was used to study the spectral properties of a nitroxide spin probe in ethanol glass and crystalline ethanol, at $5--11.5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The different anisotropy molecular packing two host matrices evidenced by rigid limit values for maximal hyperfine splitting signal probe. significantly shorter phase memory time ${T}_{m}$ dissolved as compared glass, discussed terms contribution from diffusion. effect...
Abstract The purpose of this research is to upgrade the mathematical modeling and computer simulation steel quenching. Based on theoretical analyses physical processes that exist in quenching systems, model for established software developed. focused phenomena, such as heat transfer, phase transformations, mechanical properties, generation stresses distortions. numerical procedure divided into three parts: calculation transient temperature field, change, behaviors during based finite volume...
We have investigated the electron phase-memory relaxation time of nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl at temperatures between 5 and 80 K in crystalline glassy states ethanol using pulsed X-band paramagnetic resonance spectroscopy. The results indicate that transition from slow to fast motion regimes center occurs upon further cooling sample below ∼20 K. provide experimental evidence this phenomenon cannot be ascribed impact hyperfine interactions with methyl protons system,...
A novel series of C-11-functionalized 3,9-propano-8-aza-9H-xanthine and related compounds have been synthesized. With 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 11-methylsulphonyloxy-3,9-propano-8-aza-9H-xanthine (11) underwent a regiospecific elimination to give 9,3-propeno-8-aza-9H-xanthine (19). An equally interesting result was obtained from (19) on osmium tetraoxide oxidation, when 10,11-dihydroxy-3,9-propano-8-aza-9H-xanthine (20) formed then transformed into...
Abstract Novel pyrimido[1,2-a]pyrimidinones 14, 15 and 16 imidazo[1,2-a] pyrimidinones 19 20, designed as conformationally constrained analogues of 1-(3-amino-2-hydroxypropyl)thymine 1-(2-amino-3-hydroxypropyl)thymine, respectively, were synthesized by the ring-opening/ ring-closure rearrangement corresponding byciclic oxygen-containing amino compounds 12 17.