TY  - JOUR
A1  - Schneider, Leon N.
A1  - Tanzer Krauel, Eva-Maria
A1  - Deutsch, Carl
A1  - Urbahns, Klaus
A1  - Bischof, Tobias
A1  - Maibom, Kristina A. M.
A1  - Landmann, Johannes
A1  - Keppner, Fabian
A1  - Kerpen, Christoph
A1  - Hailmann, Michael
A1  - Zapf, Ludwig
A1  - Knuplez, Tanja
A1  - Bertermann, Rüdiger
A1  - Ignat'ev, Nikolai V.
A1  - Finze, Maik
T1  - Stable and Storable N(CF\(_{3}\))\(_{2}\) Transfer Reagents
JF  - Chemistry—A European Journal
N2  - Fluorinated groups are essential for drug design, agrochemicals, and materials science. The bis(trifluoromethyl)amino group is an example of a stable group that has a high potential. While the number of molecules containing perfluoroalkyl, perfluoroalkoxy, and other fluorinated groups is steadily increasing, examples with the N(CF\(_{3}\))\(_{2}\) group are rare. One reason is that transfer reagents are scarce and metal-based storable reagents are unknown. Herein, a set of Cu\(^{I}\) and Ag\(^{I}\) bis(trifluoromethyl)amido complexes stabilized by N- and P-donor ligands with unprecedented stability are presented. The complexes are stable solids that can even be manipulated in air for a short time. They are bis(trifluoromethyl)amination reagents as shown by nucleophilic substitution and Sandmeyer reactions. In addition to a series of benzylbis(trifluoromethyl)amines, 2-bis(trifluoromethyl)amino acetate was obtained, which, upon hydrolysis, gives the fluorinated amino acid N,N-bis(trifluoromethyl)glycine.
KW  - silver
KW  - amination
KW  - copper
KW  - fluorinated ligands
KW  - N ligands
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256890
VL  - 27
IS  - 42
ER  - 
TY  - JOUR
A1  - Ojha, Animesh K.
A1  - Forster, Stefan
A1  - Kumar, Sumeet
A1  - Vats, Siddharth
A1  - Negi, Segeeta
A1  - Fischer, Ingo
T1  - Synthesis of well-dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains
JF  - Journal of Nanobiotechnology
N2  - In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 +/- 0.1, 1.8 +/- 0.1 and 1.2 +/- 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B. subtilis (gram positive) and E. coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B. subtilis (gram positive) and E. coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.
KW  - silver
KW  - nano rods
KW  - TEM
KW  - antimicrobial activities
KW  - nanowire formation
KW  - gold nanoparticles
KW  - Raman-scattering
KW  - nanostructures
KW  - particles
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122837
SN  - 1477-3155
VL  - 11
IS  - 42
ER  - 
TY  - JOUR
A1  - Ojha, Animesh K.
A1  - Forster, Stefan
A1  - Kumar, Sumeet
A1  - Vats, Siddharth
A1  - Negi, Sangeeta
A1  - Fischer, Ingo
T1  - Synthesis of well–dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains
JF  - Journal of Nanobiotechnology
N2  - In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 ± 0.1, 1.8 ± 0.1 and 1.2 ± 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B. subtilis (gram positive) and E. coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B. subtilis (gram positive) and E. coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.
KW  - antimicrobial activities
KW  - silver
KW  - nano rods
KW  - TEM
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132222
VL  - 11
IS  - 42
ER  -