Search results for "assembly"
showing 10 items of 768 documents
Controlled orientation and alignment in films of halloysite nanotubes by liquid-crystalline processing
2014
Design and construction of halogen-bonded capsules and cages
2017
This thesis describes the design, synthesis and characterization of supramolecular halogen-bonded capsules and cages from multivalent ligands. In the first part of the thesis, an overview to halogen bonding is provided. After discussing the general features of the halogen bonding, the most frequently used halogen bond donors are introduced and examples of their utilization in halogen-bonded systems are discussed. The chapter also presents recent advances made in the field of halogen-bonded supramolecular capsules. The first part of the thesis also includes a review of halogen-bonded complexes involving halonium ions, and a brief introduction to [N···X+···N] halogen bonds is provided along w…
Expansion and Compression of a Helicate with Central Diol-Units as Stereocontrolling Moieties
2022
The dicatechol ester ligand 2-H4 forms the compressed helicate Li4[(2)3Ti2] which upon removal of the internally bound lithium cations expands. In the compressed form, the chiral diol units control the stereochemistry of the complex which is lost upon expansion of the system. peerReviewed
One‐pot synthesis of [2+2]‐helicate‐like macrocycle and 2+4‐μ4‐oxo tetranuclear open frame complexes : Chiroptical properties and asymmetric oxidativ…
2020
Synthesis of binuclear Cu(II) terminally closed [2+2]‐ double‐stranded helicate‐like macrocycles 1, 1′,1″, 2, 2′, 2″ and 2+4‐μ4‐oxo tetranuclear open frame complexes 3, 3′, 3″, 4, 4′, 4″ are established. Adapting one‐pot self‐assembly technique from simple three components systems: 1,1′‐binaphthyl‐2,2′‐diamine, 4‐methyl‐2,6‐diformyl phenol and cupric salts, the helicate‐like [2+2]‐ macrocyclic complexes 1–1″, 2–2″ and 2+4‐μ4‐oxo tetranuclear complexes 3–3″, 4–4″ were obtained by appropriately altering the reaction condition such as temperature and subcomponent ratio. Density Functional Theory (DFT) calculations were carried out for understanding the structural geometries, intermediates invo…
Self-assembly of 2,8,14,20-tetraisobutyl-5,11,17,23-tetrahydroxyresorc[4]arene
1999
We report herein the observation of a hexameric structure of a hydroxyresorc[4]arene in the solid state, enclosing a large interior space. This artificial molecular container is stabilized only by hydrogen bonds. The tendency to form aggregates in solution is demonstrated mainly by means of ESI-MS methods.
Genetics of familial hypobetalipoproteinemia
2007
Primary hypobetalipoproteinemias include three monogenic disorders: the relatively frequent codominant familial hypobetalipoproteinemia (FHBL), the rare recessive conditions abetalipoproteinemia (ABL) and chylomicron retention disease (CMRD). Approximately 50% of FHBL patients are carriers of mutations in the APOB gene, mostly causing the formation of truncated forms of ApoB. In some kindred, FHBL is linked to a locus on chromosome 3 (3p21), but the candidate gene is still unknown. Recently, a FHBL-like phenotype was observed in carriers of mutations of the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene causing loss-of-function of the encoded protein, a proprotein convertase tha…
Metal ions modulate thermal aggregation of betalactoglobulin: a join chemical and physical characterization
2014
Abstract Molecular basis of the role played by Cu 2 + and Zn 2 + ions during the thermal aggregation processes of beta-lactoglobulin (BLG) was studied by using a joint application of different techniques. In particular, Raman spectroscopy was very useful in identifying the different effects caused by the two metals at molecular level (i.e. changes in His protonation state, disulfides bridge conformation, and micro-environment of aromatic residues), evidencing the primary importance of the protein charge distribution during the aggregation process. Both metal ions are able to act on this factor and favor the protein aggregation, but Zn 2 + is able to alter the natural conformational state of…
Nano-sized I12L6 Molecular Capsules Based on the [N⋅⋅⋅I+⋅⋅⋅N] Halogen Bond
2017
Summary Self-assembly of pre-organized subunits with a concave overall shape is an effective strategy for the synthesis of supramolecular capsules. We report the synthesis of a cavitand-based hexameric capsule held together solely by 12 robust [N⋅⋅⋅I + ⋅⋅⋅N] halogen bonds and its characterization in solution and in the gas phase via 1 H NMR spectroscopy, diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY), and electrospray ionization mass spectrometry. The [N⋅⋅⋅I + ⋅⋅⋅N] halogen-bonded hexameric capsule was efficiently synthesized from the isolobal metallosupramolecular Ag + capsule by application of the [N⋅⋅⋅Ag + ⋅⋅⋅N] → [N⋅⋅⋅I + ⋅⋅⋅N] cation-exchange reaction.
Self-assembly mechanism based on charge density topological interaction energies
2017
The packing interactions have been evaluated in the context of the self-assembly mechanism of crystal growth and also for its impacts on the aromaticity of the trimesate anion. The structure of ethylammonium trimesate hydrate (1) measured at 100 K and a charge density model, derived in part from theoretical structures, is reported. Theoretical structure factors were obtained from the geometry-optimized periodic wave function. The trimesic acid portion of 1 is fully deprotonated and participates in a variety hydrogen bonding motifs. Topological analysis of the charge density model reveals the most significant packing interactions and is then compared to a complementary analysis performed by …