0000000001299035
AUTHOR
S. Nummelin
Crystal structures of 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide and bis(2,2′-bipyridin-1-ium) 1,1,3,3-tetracyano-2-(dicyanomethylene)propane-1,3-diide
In each of the title compounds, the anion shows evidence of extensive electronic delocalization. A combination of N—H⋯N and X—H⋯N hydrogen bonds links the ions in (I) into a ribbon of alternating centrosymmetric (18) and (26) rings, and those in (II) into simple (7) chains of alternating cations and anion with further cations pendent from the chain.
Generic Method for Modular Surface Modification of Cellulosic Materials in Aqueous Medium by Sequential Click-Reaction and Adsorption
A generic approach for heterogeneous surface modification of cellulosic materials in aqueous medium, applicable for a wide range of functionalizations, is presented. In the first step, carboxymethyl cellulose (CMC) modified with azide or alkyne functionality, was adsorbed on a cellulosic substrate, thus, providing reactive sites for azide–alkyne cycloaddition click reactions. In the second step, functional units with complementary click units were reacted on the cellulose surface, coated by the click-modified CMC. Selected model functionalizations on diverse cellulosic substrates are shown to demonstrate the generality of the approach. The concept by sequentially combining the robust physic…
Thermal and X-ray powder diffraction studies of aliphatic polyester dendrimers
The syntheses and thermal and X-ray powder diffraction analyses of three sets of aliphatic polyester dendrimers based on 2,2-bis(hydroxymethyl)propionic acid as a repeating unit and 2,2-dimethyl-1,3-propanediol, 1,5-pentanediol, and 1,1,1-tris(hydroxymethyl)ethane as core molecules are reported. These dendritic polyesters were prepared in high yields with the divergent method. The thermal properties of these biodendrimers were evaluated with thermogravimetric analysis and differential scanning calorimetry. The thermal decomposition of the compounds occurred around 250 °C for the hydroxyl-ended dendrimers and around 150 °C for the acetonide-protected dendrimers. In addition, the crystallinit…
Bisfunctionalized Janus Molecules
[reaction: see text] Bisfunctionalized dendritic multiester molecules were synthesized by combined protection-deprotection and divergent-convergent-divergent sequences in high yields leading to dendritic molecules that combine two functionally different surfaces, polar aliphatic arborol and nonpolar gallate ether moieties, resulting in a two-faced Janus molecule.
3,4,5-Trimethoxy-4'-methylbiphenyl
In the title compound, C16H18O3, the dihedral angle between the benzene rings is 33.4 (2)°. In the crystal, molecules are packed in a zigzag arrangement along the b-axis and are interconnected via weak C—H⋯O hydrogen bonds, and C—H⋯π interactions involving the methoxy groups and the benzene rings of neighbouring molecules.
3,4-Dimethoxy-4'-methylbiphenyl
In the title compound, C15H16O2, the dihedral angle between the planes of the aromatic rings is 30.5 (2). In the crystal, molecules are linked via C—HO hydrogen bonds and C— H interactions, forming a two-dimensional network lying parallel to (100). peerReviewed
3,5-Dimethoxy-4'-methylbiphenyl
The title compound, C15H16O2, crystallizes with three independent molecules in the asymmetric unit. The intramolecular torsion angle between the aromatic rings of each molecule are −36.4 (3), 41.3 (3) and −37.8 (3)°. In the crystal, the complicated packing of the molecules forms wave-like layers along the b and c axes. The molecules are connected via extensive methoxy–phenyl C—H…π interactions. A weak C—H…O hydrogen-bonding network also exists between methoxy O atoms and aromatic or methoxy H atoms.
Methyl 3',5'-dimethoxybiphenyl-4-carboxylate
In the title compound, C16H16O4, the dihedral angle between the benzene rings is 28.9 (2)°. In the crystal, molecules are packed in layers parallel to the b axis in which they are connected via weak intermolecular C-H...O contacts. Face-to-face π-π interactions also exist between the benzene rings of adjacent molecules, with centroid-centroid and plane-to-plane shift distances of 3.8597 (14) and 1.843 (2) Å, respectively.
Dynamic DNA Origami Devices: from Strand-Displacement Reactions to External-Stimuli Responsive Systems
DNA nanotechnology provides an excellent foundation for diverse nanoscale structures that can be used in various bioapplications and materials research. Among all existing DNA assembly techniques, DNA origami proves to be the most robust one for creating custom nanoshapes. Since its invention in 2006, building from the bottom up using DNA advanced drastically, and therefore, more and more complex DNA-based systems became accessible. So far, the vast majority of the demonstrated DNA origami frameworks are static by nature; however, there also exist dynamic DNA origami devices that are increasingly coming into view. In this review, we discuss DNA origami nanostructures that exhibit controlled…
Self-assembly of janus dendrimers into uniform dendrimersomes and other complex architectures
Janus Drug Delivery Vehicle Efficient drug delivery vehicles need to be produced in a limited size range and with uniform size distribution. The self-assembly of traditional small-molecule and polymeric amphiphiles has led to the production of micelles, liposomes, polymeric micelles, and polymersomes for use in drug delivery applications. Now, Percec et al. (p. 1009 ) describe the self-assembly of Janus-type (i.e., two-headed) dendrimers to produce monodisperse supramolecular constructs, termed “dendrimersomes,” and other complex architectures. The structures, which showed long-term stability as well as very narrow size distributions, were easily produced by the injection of an ethanolic so…
Polyester and Ester Functionalized Dendrimers
Demand for smart and functional materials has raised the importance of the research of dendritic (Greek = tree-like) molecules in organic and polymer chemistry due to their novel physical and mechanical properties. The properties of linear polymers as well as small discrete molecules are combined in this new architectural class of macromolecules, that can be divided into two families: dendrimers and hyperbranched macromolecules, that differ in their branching sequences. Dendrimers contain symmetrically arranged branches emanating from a core molecule together with a well-defined number of end groups corresponding to each generation. This results in an almost monodisperse three-dimensional g…
DNA-Based Enzyme Reactors and Systems
During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme) cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular…
High-Generation Amphiphilic Janus-Dendrimers as Stabilizing Agents for Drug Suspensions
Pharmaceutical nanosuspensions are formed when drug crystals are suspended in aqueous media in the presence of stabilizers. This technology offers a convenient way to enhance the dissolution of poorly water-soluble drug compounds. The stabilizers exert their action through electrostatic or steric interactions, however, the molecular requirements of stabilizing agents have not been studied extensively. Here, four structurally related amphiphilic Janus-dendrimers were synthesized and screened to determine the roles of different macromolecular domains on the stabilization of drug crystals. Physical interaction and nanomilling experiments have substantiated that Janus-dendrimers with fourth gen…
Methyl 3',4',5'-trimethoxybiphenyl-4-carboxylate
In the title compound, C17H18O5, the dihedral angle between the benzene rings is 31.23 (16)°. In the crystal, the molecules are packed in an antiparallel fashion in layers along the a axis. In each layer, very weak C-H...O hydrogen bonds occur between the methoxy and methyl ester groups. Weak C-H...[pi] interactions between the 4'- and 5'-methoxy groups and neighbouring benzene rings [methoxy-C-ring centroid distances = 4.075 and 3.486 Å, respectively] connect the layers.
CCDC 1496221: Experimental Crystal Structure Determination
Related Article: F. Setifi, A. Valkonen, Z. Setifi, S. Nummelin, R. Touzani, C. Glidewell|2016|Acta Crystallogr.,Sect.E:Cryst.Commun.|72|1246|doi:10.1107/S2056989016012160
CCDC 954260: Experimental Crystal Structure Determination
Related Article: M. Lahtinen and S. Nummelin|2013|Acta Crystallogr.,Sect.E:Struct.Rep.Online|69|o681|doi:10.1107/S1600536813008957
CCDC 250577: Experimental Crystal Structure Determination
Related Article: S.Nummelin, D.Falabu, A.Shivanyuk, K.Rissanen|2004|Org.Lett.|6|2869|doi:10.1021/ol049179z
CCDC 250578: Experimental Crystal Structure Determination
Related Article: S.Nummelin, D.Falabu, A.Shivanyuk, K.Rissanen|2004|Org.Lett.|6|2869|doi:10.1021/ol049179z
CCDC 1059033: Experimental Crystal Structure Determination
Related Article: Z. Setifi, A. Valkonen, M.A. Fernandes, S. Nummelin, H. Boughzala, F. Setifi, C. Glidewell|2015|Acta Crystallogr.,Sect.E:Cryst.Commun.|71|509|doi:10.1107/S2056989015007306
CCDC 956780: Experimental Crystal Structure Determination
Related Article: M. Lahtinen, K. Nättinen and S. Nummelin|2013|Acta Crystallogr.,Sect.E:Struct.Rep.Online|69|o810|doi:10.1107/S1600536813010969
CCDC 935635: Experimental Crystal Structure Determination
Related Article: M.Lahtinen,K.Nattinen,S.Nummelin|2013|Acta Crystallogr.,Sect.E:Struct.Rep.Online|69|o510|doi:10.1107/S1600536813006053
CCDC 250576: Experimental Crystal Structure Determination
Related Article: S.Nummelin, D.Falabu, A.Shivanyuk, K.Rissanen|2004|Org.Lett.|6|2869|doi:10.1021/ol049179z
CCDC 935539: Experimental Crystal Structure Determination
Related Article: M.Lahtinen,K.Nattinen,S.Nummelin|2013|Acta Crystallogr.,Sect.E:Struct.Rep.Online|69|o460|doi:10.1107/S1600536813005333
CCDC 250579: Experimental Crystal Structure Determination
Related Article: S.Nummelin, D.Falabu, A.Shivanyuk, K.Rissanen|2004|Org.Lett.|6|2869|doi:10.1021/ol049179z
CCDC 1059034: Experimental Crystal Structure Determination
Related Article: Z. Setifi, A. Valkonen, M.A. Fernandes, S. Nummelin, H. Boughzala, F. Setifi, C. Glidewell|2015|Acta Crystallogr.,Sect.E:Cryst.Commun.|71|509|doi:10.1107/S2056989015007306
CCDC 935488: Experimental Crystal Structure Determination
Related Article: M.Lahtinen,K.Nattinen,S.Nummelin|2013|Acta Crystallogr.,Sect.E:Struct.Rep.Online|69|o383|doi:10.1107/S1600536813004133