280 research outputs found
Modular Synthesis of Linear Bis- and Tris-monodentate Fused [6]Polynorbornane-Based Ligands and their Assembly into Coordination Cages
No full textA modular approach has been developed for the synthesis of rigid linear di- and tritopic ligands based on a fused [6]polynorbornane scaffold. The design provides up to three sites for installing functionality, including both "ends" and a "central" position with the advantage that each region can be independently addressed during synthesis. To illustrate the utility of the approach, both pyridyl and picolyl units were incorporated to provide six new ligands, with centers and ends either matched or mismatched. Indeed, both [M2L4] cages with endohedral functionality and [M3L4] complexes were cleanly produced from these ligands with assembled structures confirmed by using H-1 NMR spectroscopy, HRMS, and molecular modelling
Rapid Solvent-Free Synthesis of Pyridyl-Functionalised [5]Polynorbornane-Based Ligands for Metal-Organic Rings and Cages
No full textA solvent-free multicomponent protocol for the rapid (<30 min) synthesis of pyridyl-functionalised [5]polynorbornane ligands is described in which both 1,3-dipolar cycloaddition and imide formation occur. The ligands produced by this approach have been incorporated into new Pd and Pt M1L2 chelate complexes as well as an M2L4 cage as elucidated from NMR spectroscopy, ESI-MS and computational data
A fluorescent and solvatochromic 1,8-naphthalimide probe for detection of lipid droplet trafficking and biogenesis
No full textData source: Supplementary data, https://doi.org/10.1016/j.dyepig.2023.111382We present a highly fluorescent, solvatochromic, 1,8-naphthalimide for simultaneous imaging of lipid droplets and endoplasmic reticulum, with distinguishable emission maxima. By delineating organelles based on their emission profiles, lipid droplet biogenesis and intercellular trafficking events are visualised. The probe also stains myelin lipids in ex vivo brain tissue, indicating histochemical applications.Shane M. Hickey, Ian R.D. Johnson, Elena Dallerba, Mark J. Hackett, Massimiliano Massi, Joanna Lazniewska, Lauren A. Thurgood, Frederick M. Pfeffer, Douglas A. Brooks, Trent D. Ashto
Desymmetrization of an octahedral coordination complex inside a self-assembled exoskeleton.
No full textThe synthesis of a centrally functionalized, ribbon-shaped [6]polynorbornane ligand L that self-assembles with Pd(II) cations into a {Pd2 L4 } coordination cage is reported. The shape-persistent {Pd2 L4 } cage contains two axial cationic centers and an array of four equatorial H-bond donors pointing directly towards the center of the cavity. This precisely defined supramolecular environment is complementary to the geometry of classic octahedral complexes [M(XY)6 ] with six diatomic ligands. Very strong binding of [Pt(CN)6 ](2-) to the cage was observed, with the structure of the host-guest complex {[Pt(CN)6 ]@Pd2 L4 } supported by NMR spectroscopy, MS, and X-ray data. The self-assembled shell imprints its geometry on the encapsulated guest, and desymmetrization of the octahedral platinum species by the influence of the D4h -symmetric second coordination sphere was evidenced by IR spectroscopy. [Fe(CN)6 ](3-) and square-planar [Pt(CN)4 ](2-) were strongly bound. Smaller octahedral anions such as [SiF6 ](2-) , neutral carbonyl complexes ([M(CO)6 ]; M=Cr, Mo, W) and the linear [Ag(CN)2 ](-) anion were only weakly bound, showing that both size and charge match are key factors for high-affinity binding
Pfeing, Frederick (Birth, 1895-11-06)
No full textAddress: 30 Clifton Avenue6291/Pg 150/1895/M W/Ger./Ger./Katherine Pfeffer, Mid.Original record filed in drawer labeled 'PETRI-PFLUNG'
Torque vectoring control for different powertrain layouts of hybrid and electric vehicles
No full textIn recent years the need in energy saving in transportation raised the attention on alternative powertrain. The main competitor of ICE become electric motors. With this type of powertrain it is possible to drastically change the power train layout of a vehicle. It is in fact possible to equip the vehicle with more than one single motor. In this paper the author analyses the effectiveness of a control strategy for lateral dynamics applied on different powertrain layouts comparing the performance of each layout with respect to others and with respect to the passive equivalent vehicle
Pfeffer, Frederick J. (Birth, 1907-08-23)
No full textAddress: 62 Neff Avenue7/Pg. 145/1907/M W/Cinti, Ohio/Ger./Emily Hochstrasser, Mid.Original record filed in drawer labeled 'PETRI-PFLUNG'
A 3,4-dimethoxy-1,8-naphthalimide for lipid droplet imaging in live and fixed cells
No full textData source: Supplementary data, https://doi.org/10.1016/j.snb.2022.131921Lipid droplets (LDs) are found in most eukaryotic cells and in addition to serving as lipid reservoirs, these highly dynamic organelles play fundamental roles in cell metabolism and growth. The study of LDs and their in- teractions with other cellular compartments provides new insights into normal cell biology and disease processes such as virus packaging, metabolic disorders, and cancer progression. Here we report the synthesis and comprehensive evaluation of two readily prepared, low molecular weight 3,4-dimethoxy-1,8-naphthalimides, as selective LD stains. The newly synthesised 1,8-naphthalimide derivative (DMN-LD), demonstrated impressive versatility compared to currently available options, by staining LDs in both live and fixed cells, as well as a three- dimensional spheroid, using both single and two-photon excitation. This new imaging agent has the potential to further unravel the complex biology of LDs, which are essential to cell survival, and when altered, underpin many disease states.Ian R.D. Johnson, Elley E. Rudebeck, Martin J. Sweetman, Alexandra Sorvina, Trent D. Ashton, Frederick M. Pfeffer, Douglas A. Brooks, Shane M. Hicke
Molecular recognition of DNA by rigid [n]-polynorbornane-derived bifunctional intercalators: Synthesis and evaluation of their binding properties
No full textCopyright © 2007 American Chemical SocietyWe have exploited the concept of multivalency in the context of DNA recognition, using novel chemistry to synthesize a new type of bis-intercalator with unusual sequence-selectivity. Bis-intercalation has been observed previously, but design principles for de novo construction of such molecules are not known. Our compounds feature two aromatic moieties projecting from a rigid, polynorbornane-based scaffold. The length and character of the backbone as well as the identity of the intercalators were varied, resulting in mono- or divalent recognition of the double helix with varying affinity. Our lead compound proved to be a moderately sequence-selective bis-intercalator with an unwinding angle of 27 degrees and a binding constant of about 8 microM. 9-aminoacridine rings were preferred over acridine carboxamides or naphthalimides, and a rigid [3]-polynorbornane scaffold was superior to a [5]-polynorbornane. The flexibility of the linker connecting the rings to the scaffold, although less influential, could affect the strength and character of the DNA binding.Liisa D. Van Vliet, Tom Ellis, Patrick J. Foley, Ligong Liu, Frederick M. Pfeffer, Richard A. Russell, Ronald N. Warrener, Florian Hollfelder, and Michael J. Warin
ChemInform Abstract: Synthesis of Norbornane Bisether Antibiotics via Silver‐Mediated Alkylation.
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