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.
PROCESS FOR PREPARING CYCLIC ALKYLENE UREAS
-
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.
PROCESS FOR CONVERTING CYCLIC ALKYLENEUREAS INTO THEIR CORRESPONDING ALKYLENEAMINES
-
Page/Page column 13; 14; 15; 16, (2019/02/25)
The present invention is directed to a process for converting cyclic alkyleneureas into their corresponding alkyleneamines wherein a feedstock comprising cyclic alkyleneureas is reacted in the liquid phase with water in an amount of 0. -20 mole water per mole urea moiety, at a temperature of at least 230°C, with removal of CO2. It has been found that the process according to the invention allows the efficient conversion of alkyleneureas into the corresponding alkyleneamines. The process has a high yield and low side product production. It is preferred for the cyclic alkyleneurea to comprises one or more of EU (ethyleneurea, the urea derivative of ethylenediamine (EDA)), UDETA (the urea derivative of diethylenetriamine (DETA)), UTETA (the group of urea derivatives of triethylenetetraamine (TETA), DUTETA (the diurea derivative of triethylenetetramine), UTEPAs (the urea derivatives of tetraethylenpentamine (TEPA)), DUTEPAs (the diurea derivatives of TEPA), or urea derivatives of pentaethylenehexamine (PEHA) and higher analogues, UAEEA (the urea derivative of aminoethylethanolannine), HE-UDETA (the urea derivative of hydroxyethyl diethylenetriamine), HE-UTETA (the urea derivative of hydroxyethyl triethylenetetraamine, HE-DUTETA (the diurea derivative of hydroxyethyl triethylenetetraamine), or any mixture of these.