Search results for "Chloroform"
showing 10 items of 414 documents
Synthesis of Novel Folic Acid-Functionalized Biocompatible Block Copolymers by Atom Transfer Radical Polymerization for Gene Delivery and Encapsulati…
2005
Two synthetic routes to folic acid (FA)-functionalized diblock copolymers based on 2-(methacryloyloxy)- ethyl phosphorylcholine [MPC] and either 2-(dimethylamino)ethyl methacrylate [DMA] or 2-(diisopropylamino) ethyl methacrylate [DPA] were explored. The most successful route involved atom transfer radical polymerization (ATRP) of MPC followed by the tertiary amine methacrylate using a 9-fluorenylmethyl chloroformate (Fmoc)-protected ATRP initiator. Deprotection of the Fmoc groups produced terminal primary amine groups, which were conjugated with FA to produce two series of novel FA-functionalized biocompatible block copolymers. Nonfunctionalized MPC-DMA diblock copolymers have been previou…
Quality control Fourier transform infrared determination of diazepam in pharmaceuticals
2007
A quality control procedure has been developed for the determination of diazepam in pharmaceuticals using Fourier transform infrared (FTIR) spectroscopy. The method involves the off-line extraction of diazepam with chloroform by sonication and direct determination in the extracts through peak area measurement in the interval between 1672 and 1682 cm(-1) using a baseline correction defined between 1850 and 1524 cm(-1). For standardization it was used an external calibration line established from standard solutions of diazepam in chloroform. The method provides a limit of detection of 0.04 mg per tablet (n=5), a relative standard deviation (R.S.D.) of 0.5% for 5 independent measurements of a …
Structural re-arrangement in two hexanuclear CuIIcomplexes: from a spin frustrated trigonal prism to a strongly coupled antiferromagnetic soluble rin…
2014
The addition of water to a chloroform solution of the Cu6 trigonal prism complex [Cu6(μ6F)(μ2OH)(μ3OCH3)2(μ2OCH3)2(3,5-Me2pz)6] (1) (3,5-Me2pz− = 3,5-dimethylpyrazolate) results in the formation of the Cu6 planar hexagonal ring complex [Cu6(μ2OH)6(3,5-Me2pz)6]·CH3CN·CHCl3 (2). A simple mechanism for this structural re-arrangement is proposed, in which 2 can be viewed as a hydrolysis product of 1. This process is clearly noticeable in the magnetic properties, which change from spin frustrated with a weak antiferromagnetic coupling in 1, to strongly antiferromagnetic in 2. Interestingly, the hexagonal ring complex 2 self-assembles in the solid state to form a porous hexagonal tubular structur…
UCST-type behavior of poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) in aliphatic alcohols: solvent, co-solvent, molecular weight, a…
2011
Poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) is shown to possess insoluble–soluble transitions (UCST-type phase behavior) in a large variety of aliphatic alcohols. Samples of different molecular weights ranging from 5 kg mol−1 to 23 kg mol−1 prepared by the RAFT process and featuring different end groups at each end were analyzed by cloud point measurements. Transitions occurred sharply and were fully reversible. The UCST was found to increase with an increasing molecular weight. Hydrophobic (alkyl chain) end groups were found to lower the critical temperature in isopropanol, while rigid aromatic end groups raised the transition temperature. In ternary mixtures of isoprop…
Moleküldimensionen von polymeren in verschiedenen lösungsmitteln auf grund hydrodynamischer messungen
1960
Ein fraktioniertes Polystyrol vom Molekulargewicht Mw ≈ 540000 wurde in Chloroform, Toluol, Methylathylketon und Cyclohexan sowie in drei Mischungen von Toluol und Methylathylketon untersucht. Da das Chloroform ein gutes, das Cyclohexan dagegen ein Θ-Losungsmittel fur Polystyrol darstellt, nehmen die Dimensionen des Fadenmolekuls beim Ubergang zwischen den Losungsmitteln ab. Mit den Knaueldimensionen andern sich Reibung und Viskositat des Polystyrols. Messungen der Sedimentationskonstanten, der Diffusionskonstanten, der Viskositatszahl sowie der Dichte und der Zahigkeit fur die gemischten Losungsmittel wurden ausgefuhrt. Die Ergebnisse der Messungen werden benutzt, um aus der Viskositatsthe…
Partielle spezifische refraktionen von polymethylmethacrylat und polystyrol. I. Einfluß verschiedener lösungsmittel
1969
Auf der Grundlage der Formeln von LORENTZ-LORENZ, GLADSTONE-DALE und EYKMAN wurden die partiellen spezifischen Refraktionen von Polymethylmethacrylat in den Losungsmitteln Aceton, Athylacetat, Butylacetat, Tetrahydrofuran, Dioxan, Chloroform, Toluol und Benzol sowie die von Polystyrol in Butanon, Dioxan, Toluol und Benzol bestimmt. Es zeigt sich, das these Werte, die mit einer Genauigkeit von ± 0,1% aus den experimentellen Grosen Brechungsindex-Inkrement, Brechungsindex der Losung und partielles spezifisches Volumen berechnet wurden, nicht ganz frei von Losungsmitteleinflussen sind. Der groste Unterschied wurde bei den LORENTZ-LORENZ-Refraktionen gefunden und betrug 1,3%. Die EYKMAN-Refrakt…
CCDC 1904437: Experimental Crystal Structure Determination
2019
Related Article: Marina V. Volostnykh, Sergey M. Borisov, Mikhail A. Konovalov, Anna A. Sinelshchikova, Yulia G. Gorbunova, Aslan Yu. Tsivadze, Michel Meyer, Christine Stern, Alla Bessmertnykh-Lemeune|2019|Dalton Trans.|48|8882|doi:10.1039/C9DT01577A
CCDC 1009209: Experimental Crystal Structure Determination
2016
Related Article: Xin Ding, Matti J. Tuikka, Pipsa Hirva, Vadim Yu. Kukushkin, Alexander S. Novikov, Matti Haukka|2016|CrystEngComm|18|1987|doi:10.1039/C5CE02396C
CCDC 1009212: Experimental Crystal Structure Determination
2016
Related Article: Xin Ding, Matti J. Tuikka, Pipsa Hirva, Vadim Yu. Kukushkin, Alexander S. Novikov, Matti Haukka|2016|CrystEngComm|18|1987|doi:10.1039/C5CE02396C
CCDC 1456509: Experimental Crystal Structure Determination
2016
Related Article: Daniil M. Ivanov, Alexander S. Novikov, Galina L. Starova, Matti Haukka, Vadim Yu. Kukushkin|2016|CrystEngComm|18|5278|doi:10.1039/C6CE01179A