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51.
Anthony F. Cannella Roshaan Surendhran Samantha N. MacMillan Rupal Gupta 《Journal of Coordination Chemistry》2019,72(8):1287-1297
AbstractThis report details the synthesis and characterization of six new Mn(II) complexes coordinated to systematically varied 2,2',2''-nitrilotris(N-arylacetamidate) ligands (LR; R?=?NO2, Cl, Br, H, Me, and OMe). The complexes are synthesized as the di-tetramethylammonium salts [Me4N]2[MnLR(OAc)]. The nitro variant MnNO2 afforded crystals suitable for X-ray diffraction and its molecular structure is reported. We previously reported the crystal structures of FeNO2 and ZnNO2 and additionally report herein the synthesis and characterization of CoNO2. Using these four molecules, we conduct a brief comparison of the bond metrics to demonstrate that the primary difference governing structural changes is likely due to ionic crystal radii changes rather than electronic properties. The electrochemical properties of the MnR complexes were additionally explored with cyclic voltammetry, which revealed that the series is modulated by the various electronic substituents on the aryl groups of the ligands. The electrochemical studies also revealed, consistent with our previous report, that the acetate ligand on the MnR complexes is labile. Finally, a Hammett plot was constructed using the potentials obtained from cyclic voltammetry, which is compared with a few other similar transition metal complexes. 相似文献
52.
Liping Zhu Samantha Powell Stephen G. Boyes 《Journal of polymer science. Part A, Polymer chemistry》2015,53(8):1010-1022
Well‐defined tertiary amine‐based pH‐responsive homopolymers and block copolymers were synthesized via reversible addition‐fragmentation chain transfer (RAFT) polymerization using 4‐cyanopentanoic acid dithiobenzoate (CPAD) as the RAFT agent for homopolymers and a poly(ethylene glycol) (PEG) macro‐RAFT agent for the block copolymers. 1H NMR and gel permeation chromatography results confirmed the successful synthesis of these homopolymers and block copolymers. Kinetics studies indicated that the formation of both the homopolymers and the block copolymers were well defined. The pKa titration experiments suggested that the homopolymers and the related block copolymers have a similar pKa. The dynamic light scattering investigation showed that all of the block copolymers underwent a sharp transition from unimers to micelles around their pKa and the hydrodynamic diameter (Dh) was not only dependent on the molecular weight but also on the composition of the block copolymers. The polymer solution of PEG‐b‐PPPDEMA formed the largest micelle compare to the PEG‐b‐PDPAEMA and PEG‐b‐PDBAEMA with a similar molecular weight. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1010–1022 相似文献
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54.
William B. Tucker Aaron M. McCoy Samantha M. Fix Melissa F. Stagg Matt M. Murphy Sandro Mecozzi 《Journal of polymer science. Part A, Polymer chemistry》2014,52(23):3324-3336
Linear, dibranched, and miktoarm amphiphiles containing both hydrophobic and fluorophilic moieties were synthesized and characterized in an attempt to elucidate the relationship between semifluorinated amphiphile structure and aggregate behavior in aqueous solution. For the linear and dibranched amphiphiles, there was an exponential decrease in critical aggregation concentration (CMC) and a logarithmic increase in core microviscosity with increasing length of the fluorocarbon segments; while the miktoarm architecture produced no notable trend in microviscosity or CMC. Furthermore, the linear and dibranched surfactants showed enhanced kinetic stability, dissociating more slowly in the presence of human serum than did either the dibranched or miktoarm amphiphiles. Finally, encapsulation studies with the hydrophobic drug paclitaxel (PTX) showed that the ability to solubilize and retain PTX increased with the presence and with the increasing size of the fluorocarbon moiety for both the linear and dibranched amphiphiles, while no such trend was observed for the miktoarm amphiphiles. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3324–3336 相似文献
55.
Ruthenium‐Containing Linear Helicates and Mesocates with Tuneable p53‐Selective Cytotoxicity in Colorectal Cancer Cells
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Dr. Simon J. Allison Dr. David Cooke Francesca S. Davidson Prof. Paul I. P. Elliott Dr. Robert A. Faulkner Hollie B. S. Griffiths Owen J. Harper Omar Hussain Prof. P. Jane Owen‐Lynch Prof. Roger M. Phillips Prof. Craig R. Rice Samantha L. Shepherd Dr. Richard T. Wheelhouse 《Angewandte Chemie (International ed. in English)》2018,57(31):9799-9804
The ligands L1 and L2 both form separable dinuclear double‐stranded helicate and mesocate complexes with RuII. In contrast to clinically approved platinates, the helicate isomer of [Ru2( L1 )2]4+ was preferentially cytotoxic to isogenic cells (HCT116 p53?/?), which lack the critical tumour suppressor gene. The mesocate isomer shows the reverse selectivity, with the achiral isomer being preferentially cytotoxic towards HCT116 p53+/+. Other structurally similar RuII‐containing dinuclear complexes showed very little cytotoxic activity. This study demonstrates that alterations in ligand or isomer can have profound effects on cytotoxicity towards cancer cells of different p53 status and suggests that selectivity can be “tuned” to either genotype. In the search for compounds that can target difficult‐to‐treat tumours that lack the p53 tumour suppressor gene, [Ru2( L1 )2]4+ is a promising compound for further development. 相似文献
56.
We describe a simple, rapid combined method for extracting the antimalarial compound artemisinin from the leaves of Artemisia annua L. cultivated for the first time in Burundi, and quantitating the active principle by high-performance liquid chromatography-electrospray mass spectrometry. 相似文献
57.
Gelmi ML Nava D Leone S Pellegrino S Baldelli E Zunino F Cappelletti G Cartelli D Fontana G 《The Journal of organic chemistry》2008,73(22):8893-8900
The synthesis of new D-seco-C-nor-taxane derivatives in which the D-ring has been deleted and the C-ring has been transformed into a new pentatomic ring, i.e., the polyfunctionalized tetrahydrofuranosyl and cyclopentenyl or cyclopentyl ring, was performed starting from baccatin III derivatives. The synthetic strategy adopted took advantage of the oxetane ring opening and disconnection of the C4-C5 bond, followed by an intramolecular condensation. The formation of furanosyl or cyclopentyl rings is strictly dependent on the presence of unprotected or protected oxygen at C-7 in the starting material. The reactions proceeded with good diastereoselectivity with control of the stereochemistry of one or two stereocenters. 相似文献
58.
59.
We test for the first time the performance of the reference interaction site model (RISM) to predict the liquid structure and solvation of room-temperature ionic liquids (RTILs) represented with different degrees of accuracy. The model gives satisfactory results, proposing itself as a possible method to explore and to describe at a chemically realistic level the solvation shell in ionic liquids, which is believed to play a fundamental role in the static electronic and vibrational properties of these systems. 相似文献
60.
Diethylzinc-mediated radical addition to CN bonds was investigated in the presence of phenylorganotellurium compounds as radical precursors. As group transfer agents, secondary alkyl phenyl tellurides were shown to be about twice as reactive as the corresponding alkyl iodides towards ethyl radical. Their use was proven to be advantageous regarding both chemoselectivity and yield. The replacement of diethylzinc by dimethylzinc, offers no advantage in these reactions. 相似文献