111-41-1Relevant articles and documents
Multifunctional compact zwitterionic ligands for preparing robust biocompatible semiconductor quantum dots and gold nanoparticles
Susumu, Kimihiro,Oh, Eunkeu,Delehanty, James B.,Blanco-Canosa, Juan B.,Johnson, Brandy J.,Jain, Vaibhav,Hervey, William Judson,Algar, W. Russ,Boeneman, Kelly,Dawson, Philip E.,Medintz, Igor L.
, p. 9480 - 9496 (2011)
We describe the synthesis of a series of four different ligands which are used to prepare hydrophilic, biocompatible luminescent quantum dots (QDs) and gold nanoparticles (AuNPs). Overall, the ligands are designed to be compact while still imparting a zwitterionic character to the NPs. Ligands are synthesized appended to a bidentate dihydrolipoic acid- (DHLA) anchor group, allowing for high-affinity NP attachment, and simultaneously incorporate tertiary amines along with carboxyl and/or hydroxyl groups. These are placed in close proximity within the ligand structure and their capacity for joint ionization imparts the requisite zwitterionic nature to the nanocrystal. QDs functionalized with the four different compact ligands were subjected to extensive physical characterization including surface charge, wettability, hydrodynamic size, and tolerance to a wide pH range or high salt concentration over time. The utility of the compact ligand coated QDs was further examined by testing of direct conjugation to polyhistidine-appended protein and peptides, aqueous covalent-coupling chemistry, and the ability to engage in Foerster resonance energy transfer (FRET). Conjugating cell penetrating peptides to the compact ligand coated QD series facilitated their rapid and efficient cellular uptake, while subsequent cytotoxicity tests showed no apparent decreases in cell viability. In vivo biocompatibility was also demonstrated by microinjecting the compact ligand coated QDs into cells and monitoring their stability over time. Inherent benefits of the ligand design could be extended beyond QDs as AuNPs functionalized with the same compact ligand series showed similar colloidal properties. The strong potential of these ligands to expand NP capabilities in many biological applications is highlighted.
Effects of Ni particle size on amination of monoethanolamine over Ni-Re/SiO2 catalysts
Ma, Lei,Yan, Li,Lu, An-Hui,Ding, Yunjie
, p. 567 - 579 (2019/04/03)
Ni-Re/SiO2 catalysts with controllable Ni particle sizes (4.5–18.0 nm) were synthesized to investigate the effects of the particle size on the amination of monoethanolamine (MEA). The catalysts were characterized by various techniques and evaluated for the amination reaction in a trickle bed reactor at 170°C, 8.0 MPa, and 0.5 h?1 liquid hourly space velocity of MEA (LHSVMEA) in NH3/H2 atmosphere. The Ni-Re/SiO2 catalyst with the lowest Ni particle size (4.5 nm) exhibited the highest yield (66.4%) of the desired amines (ethylenediamine (EDA) and piperazine (PIP)). The results of the analysis show that the turnover frequency of MEA increased slightly (from 193 to 253 h?1) as the Ni particle sizes of the Ni-Re/SiO2 catalysts increased from 4.5 to 18.0 nm. Moreover, the product distribution could be adjusted by varying the Ni particle size. The ratio of primary to secondary amines increased from 1.0 to 2.0 upon increasing the Ni particle size from 4.5 to 18.0 nm. Further analyses reveal that the Ni particle size influenced the electronic properties of surface Ni, which in turn affected the adsorption of MEA and the reaction pathway of MEA amination. Compared to those of small Ni particles, large particles possessed a higher proportion of high-coordinated terrace Ni sites and a higher surface electron density, which favored the amination of MEA and NH3 to form EDA.
PROCESS FOR PREPARING CYCLIC ALKYLENE UREAS
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Page/Page column 17-19, (2019/02/25)
A process for producing a cyclic alkylene urea product of Formula I: in which a compound of Formula II and/or Formula III is contacted in a reaction zone with a compound of Formula IV and/or Formula V and in the presence of one or more carbonyl delivering compounds; in which; R1 is –[A?X?]qR3; R2 is on each occurrence independently selected from H and C1 to C6 alkyl groups which are optionally substituted by one or two groups selected from ?OH and ?NH2; R3 is on each occurrence independently selected from H and C1 to C6 alkyl groups which are optionally substituted by one or two groups selected from ?OH and ?NH2; A is on each occurrence independently selected from C1 to C3 alkylene units, optionally substituted by one or more C1 to C3 alkyl groups; X is on each occurrence independently selected from ?O?, ?NR2?, groups of Formula VI, and groups of Formula VII and p and q are each independently selected from a whole number in the range of from 0 to 8; wherein the compound of Formula II and/or the compound of Formula III are added to a reaction zone comprising compound of Formula IV and/or compound of Formula (V) continuously or semi-continuously over a period of time, or in two or more batches.