188011-20-3Relevant articles and documents
Giant meso-meso-linked porphyrin arrays of micrometer molecular length and their fabrication
Aratani, Naoki,Takagi, Akihiko,Yanagawa, Yoshiki,Matsumoto, Takuya,Kawai, Tomoji,Yoon, Zin Seok,Kim, Dongho,Osuka, Atsuhiro
, p. 3389 - 3404 (2005)
On the basis of the AgI-promoted coupling reaction of zinc(II)-5,15-bis(3,5-dioctyloxyphenyl)porphyrin Z1, chain elongation has been attempted by using a stepwise doubling approach, which provides Z2, Z4, Z8, Z16, Z32, Z64, Z128, Z256, Z384, and Z512. The porphyrin arrays up to Z128 are sufficiently soluble in CHCl3 and THF despite their very long molecular lengths and rodlike structures, while the arrays over Z128 show a significant drop in solubility and stability. The discrete porphyrin arrays thus isolated were characterized by means of 1H NMR spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, UV/Vis spectroscopy, gel-permeation chromatography (GPC), cyclic voltammetry (CV), single-crystal X-ray crystallography, scanning tunneling microscopy (STM), and atomic force microscopy (AFM). Contrary to expected linear conformations of the arrays Z n (where n is the number of porphyrins), the single molecular images of Z128, Z256, and Z512 revealed largely bent structures; this finding indicates the substantial conformational flexibility of Zn. We also exploited an effective synthetic route by means of which Zn can be fabricated with a thiol-protected aryl group to provide ZnS2 through ZnBr2, by bromination with N-bromosuccinimide and subsequent Pd-catalyzed Suzuki-Miyaura arylation. Finally, the reaction of Z256 provided Z512, Z768, and Z1024. Collectively, this work provides an important milestone in the preparation of sub-microscale discrete organic molecules and the fabrication of molecular-based materials, hence significantly contributing to device applications.
One-Component Multifunctional Sequence-Defined Ionizable Amphiphilic Janus Dendrimer Delivery Systems for mRNA
Atochina-Vasserman, Elena N.,Billingsley, Margaret M.,Huang, Ning,Kim, Kyunghee,Liu, Matthew,Maurya, Devendra S.,Mitchell, Michael J.,Ni, Houping,Ona, Nathan,Percec, Virgil,Pochan, Darrin J.,Shahnawaz, Hamna,Weissman, Drew,Xiao, Qi,Zhang, Dapeng
, p. 12315 - 12327 (2021/08/20)
Efficient viral or nonviral delivery of nucleic acids is the key step of genetic nanomedicine. Both viral and synthetic vectors have been successfully employed for genetic delivery with recent examples being DNA, adenoviral, and mRNA-based Covid-19 vaccines. Viral vectors can be target specific and very efficient but can also mediate severe immune response, cell toxicity, and mutations. Four-component lipid nanoparticles (LNPs) containing ionizable lipids, phospholipids, cholesterol for mechanical properties, and PEG-conjugated lipid for stability represent the current leading nonviral vectors for mRNA. However, the segregation of the neutral ionizable lipid as droplets in the core of the LNP, the "PEG dilemma", and the stability at only very low temperatures limit their efficiency. Here, we report the development of a one-component multifunctional ionizable amphiphilic Janus dendrimer (IAJD) delivery system for mRNA that exhibits high activity at a low concentration of ionizable amines organized in a sequence-defined arrangement. Six libraries containing 54 sequence-defined IAJDs were synthesized by an accelerated modular-orthogonal methodology and coassembled with mRNA into dendrimersome nanoparticles (DNPs) by a simple injection method rather than by the complex microfluidic technology often used for LNPs. Forty four (81%) showed activity in vitro and 31 (57%) in vivo. Some, exhibiting organ specificity, are stable at 5 °C and demonstrated higher transfection efficiency than positive control experiments in vitro and in vivo. Aside from practical applications, this proof of concept will help elucidate the mechanisms of packaging and release of mRNA from DNPs as a function of ionizable amine concentration, their sequence, and constitutional isomerism of IAJDs.
Synthesis, characterization and aggregation induced emission properties of anthracene based conjugated molecules
Balasaravanan, Rajendiran,Siva, Ayyanar
, p. 5099 - 5106 (2016/07/06)
Aggregation induced emission-active branched and linear 9,10-distyrylanthracene derivatives with different length alkoxy chains have been designed, synthesized and the effect of chain length on the solid-state fluorescence properties systematically investigated. All the three anthracene derivatives possess typical aggregation induced emission (AIE) properties, i.e., they exhibit faint emission in their solutions, but intense emission in their aggregate states, as a result of the dominant nonradiative decay of free intramolecular torsion in the solution and also the restricted torsional motion from supramolecular interaction in the solid states. The results show that these materials exhibit not only AIE properties, but also observed were position and chain length dependent fluorescence properties. The shorter alkoxy chains were more red shifted than the longer ones and also different aggregation behaviours for branched and linear molecules were observed. This work demonstrates once again the accessibility of tuning the solid-state optical properties of organic fluorophores by combining the simple alternation of molecular chemical structures and the physical change of aggregate morphology under external stimuli.
