OPEN Repository
Welcome to OPEN - the Repository of Open Scientific Publications, run by the Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw, previously operating as the CeON Repository. The Repository enables Polish researchers from all fields to openly share their articles, books, conference materials, reports, doctoral theses, and other scientific texts.
Publications in the Repository are indexed by the most important search engines and aggregators and downloaded by users worldwide. We invite you to create an account, deposit your publications, and use the resources of the Repository.
23068 archived items
Institutional Communities
- Loading...Police Academy in Szczytno [75]
- Loading...Centrum Badań Molekularnych i Makromolekularnych PAN [1]
- Loading...ICM UW [100]
- Loading...Instytut Badań Literackich PAN [186]
- Loading...Instytut Chemii Fizycznej PAN [182]
- Loading...Instytut Chemii Organicznej PAN [143]
- Loading...Jerzy Haber Institute of Catalysis and Surface Chemistry PAS [21]
- Loading...Instytut Paleobiologii PAN [3]
- Loading...Katedra Arabistyki i Islamistyki WO UW [131]
- Loading...Katedra Języków i Kultur Afryki WO UW [21]
- Loading...OBM UW [131]
- Loading...Uczelnia Łazarskiego [127]
- Loading...Uniwersytet Przyrodniczy w Poznaniu [92]
- Loading...Wydawnictwo Naukowe PTG [302]
- Loading...Wydział Lingwistyki Stosowanej UW [48]
- Loading...Wydział Polonistyki UW [339]
Recent Submissions
Item
Stimuli-Responsive Langmuir Films Composed of Nanoparticles Decorated with Poly(N-isopropyl acrylamide) (PNIPAM) at the Air/Water Interface
(American Chemical Society, 2023-05-31) Zbonikowski, Rafał; Iwan, Michalina; Paczesny, Jan; Instytut Chemii Fizycznej Polskiej Akademii Nauk
The nanotechnology shift from static toward stimuli-responsive systems is gaining momentum. We study adaptive and responsive Langmuir films at the air/water interface to facilitate the creation of two-dimensional (2D) complex systems. We verify the possibility of controlling the assembly of relatively large entities, i.e., nanoparticles with diameter around 90 nm, by inducing conformational changes within an about 5 nm poly(N-isopropylacrylamide)(PNIPAM) capping layer. The system performs reversible switching between uniform and nonuniform states. The densely packed and uniform state is observed at a higher temperature, i.e., opposite to most phase transitions, where more ordered phases appear at lower temperatures. The induced nanoparticles’ conformational changes result in different properties of the interfacial monolayer, including various types of aggregation. The analysis of surface pressure at different temperatures and upon temperature changes, surface potential measurements, surface rheology experiments, Brewster angle microscopy (BAM), and scanning electron microscopy (SEM) observations are accompanied by calculations to discuss the principles of the nanoparticles’ self-assembly. Those findings provide guidelines for designing other adaptive 2D systems, such as programable membranes or optical interfacial devices.
Item
Carboxylated Pillar[6]arene Emulates Pillar[5]arene in the Host–Guest Crystal Complexes and Shows Conformational Flexibility in the Solution/Gas Phase
(American Chemical Society, 2022-12-08) Butkiewicz, Helena; Kosiorek, Sandra; Sashuk, Volodymyr; Zimnicka, Magdalena; Danylyuk, Oksana; Instytut Chemii Fizycznej Polskiej Akademii Nauk; Instytut Chemii Organicznej Polskiej Akademii Nauk
Despite the thriving interest in the aqueous complexation properties of carboxylated pillar[6]arene, its solid state supramolecular chemistry has remained a mystery. Here, overcoming challenging crystallogenesis, we report the first crystallographic authentication of carboxylated pillar[6]arene in the form of two host−guest inclusion complexes with methyl viologen and pentamidine. The key to the successful crystallization of carboxylated pillar[6]arene is the mixed ionization state of its 12 carboxylic substituents. The deprotonation of several but not all substituents enables intermolecular hydrogen bonding and, as a result, “gluing” and crystallization of pillar[6]arene complexes with the aid of carboxylic-carboxylate, carboxylic-carboxylic, and amidinium-carboxylate supramolecular synthons. Single crystal X-ray diffraction analysis revealed that upon guest inclusion pillar[6]arene adopts a quasi-pentagonal shape rather than the expected hexagonal shape. The squeezed quasi-pentagonal conformation of the six-membered macrocycle is stabilized by two intramolecular hydrogen bonds between pillar[6]arene substituents. Moreover, the distinctive deviation of the macrocycle from hexagonal shape stays operative in the solution/gas phase as concluded from ion mobility mass spectrometry (IM-MS) studies and theoretical calculations. These results provide the first insight into how to gain control over the conformation of flexible pillar[6]arene with a view of solid state design of more advanced supramolecular host−guest structures.
Browse by
Selected filters: