28139-76-6Relevant academic research and scientific papers
A Track-Based Molecular Synthesizer that Builds a Single-Sequence Oligomer through Iterative Carbon-Carbon Bond Formation
McTernan, Charlie T.,De Bo, Guillaume,Leigh, David A.
supporting information, p. 2964 - 2973 (2020/11/02)
We report an artificial molecular machine that moves along a track, iteratively joining building blocks to form an oligomer of single sequence with a continuous backbone of carbon-carbon bonds. The rotaxane features a macrocycle bearing an aldehyde-terminated chain and an axle containing different phosphonium ylides separated by rigid spacers. Each ylide is large enough to block the passage of the macrocycle, trapping the ring between the stopper at the terminus of original threading and the next ylide along the track. Once a building block is reachable, it is removed from the track through a Wittig reaction that adds it to the terminus of the growing chain. Operation on a four-barrier tetra(phosphonium salt) track produces a tetra(diphenylpropane) of single sequence linked through alkene bonds. The prototype extends the principle for molecular machines that build polymers by moving along tracks to the synthesis of sequence-encoded chains with continuous carbon backbones. Sequence is crucial in the molecular world. Proteins are built from a common set of 20 amino acids, but different sequences afford materials as diverse as snake venom, muscle, and spider silk. However, the synthesis of artificial sequence polymers remains challenging. Biology uses molecular machines (e.g., ribosomes) for such tasks, inspiring the invention of artificial systems that move along tracks, picking off and joining building blocks in sequence. To date, such small-molecule machines have used amide formation to join building blocks, the same bonds the ribosome uses to make peptides. Here, we report on the design, synthesis, and operation of a track-based molecular machine that assembles a single-sequence oligomer with a continuous backbone of carbon-carbon bonds. This new class of de novo molecular synthesizer utilizes chemistry and reactivity patterns unavailable to biological machines. The long-term goal is for such molecular assemblers to ultimately be able to play significant roles in molecular construction. Molecular machines, such as ribosomes, are ubiquitous in biology. These natural systems are inspiring artificial systems that move along tracks, picking off and joining building blocks in sequence. To date, such small-molecule machines have used amide formation to connect building blocks, much like the ribosome. Here, the design, synthesis, and operation of a track-based molecular machine that iteratively forms a continuous backbone of carbon-carbon bonds is described. This new class of de novo molecular synthesizer utilizes chemistry and reactivity patterns unavailable to biological machines.
Double-anthracene D-delta-A type dark blue organic fluorescent material, and preparation method and application thereof
-
Paragraph 0088; 0090, (2020/07/15)
The invention relates to a double-anthracene D-delta-A type dark blue organic fluorescent material, and a preparation method and an application thereof. The structural formula of the material is shownin the specification; and in the formula, R1 is an elec
CARBORHODAMINE COMPOUNDS AND METHODS OF PREPARATION THEREOF
-
, (2019/12/24)
The carborhodamine dyes disclosed herein are novel reagents suitable for automated incorporation of carborhodamine dyes into oligonucleotides that can be used in detection methods for nucleic acid targets. This disclosure provides an efficient and simple
Organic blue fluorescent material and preparation method and application thereof
-
Paragraph 0074; 0076, (2019/02/10)
The invention relates to an organic blue fluorescent material and a preparation method and application thereof. The material adopts a delta bond as a bridge chain to connect two anthracene molecule luminescence units and regulate the conjugation state of organic molecules; meanwhile, a steric hindrance group is introduced onto the delta bond to inhibit a pi-pi accumulation effect among the organicmolecules, and correspondingly the organic blue fluorescent material is prepared and has high thermal stability and high luminous quantum efficiency. The specific preparation method and application mainly include the steps of adopting 9-benzanthracene-10 borate and 4,4'-dibromo diphenyl bis-substituted methane for conducting a Suzuki coupling reaction to prepare the organic blue fluorescent material. The material is adopted as a luminous layer and achieves a non-doped deep blue OLED device with high performance.
Comparison between SiMe2 and CMe2 spacers as σ-bridges for photoinduced charge transfer
Van Walree, Cornelis A.,Roest, Martin R.,Schuddeboom, Wouter,Jenneskens, Leonardus W.,Verhoeven, Jan W.,Warman, John M.,Kooijman, Huub,Spek, Anthony L.
, p. 8395 - 8407 (2007/10/03)
The potential of dimethylsilylene and isopropylidene σ-spacers as bridges for photoinduced charge transfer (CT) in 4-cyano-4'-(dimethylamino)- and 4-cyano-4'-methoxy-substituted diphenyldimethylsilanes and 2,2-diphenylpropanes was studied. Fluorescence solvatochromism and time-resolved microwave conductivity measurements show that upon photoexcitation a charge separated state (D.+σA.-)* is populated in all compounds. Excited state dipole moments for a given donor-acceptor combination are, irrespective of the bridge, equal. The CT states of the silanes are however lying at lower energies, implying that the presence of silicon thermodynamically facilitates the CT process. Cyclic voltammetry data of model compounds show that this is a consequence of the lowering of the acceptor reduction potential by the silicon bridge. It was however inferred from radiative decay rates that the electronic coupling between the CT and locally excited states as well as the coupling between the ground and CT state is larger for the carbon-bridged compounds. As shown by both solution and solid state electronic spectra and radiative decay rates, the photophysics of the DσA compounds are dominated by intensity borrowing of the CT transitions from transitions localized in the Dσ and σA chromophores.
