Cobalt-Catalyzed Dehydrogenative C−H Silylation of Alkynylsilanes

Herein, we report that a cobalt catalyst permits the general synthesis of substituted alkynylsilanes through dehydrogenative coupling of alkynylsilanes and hydrosilanes. Several silylated alkynes, including di‐ and trisubstituted ones, were prepared in a one‐step procedure. Thirty‐seven compounds were synthesized for the first time by applying our catalyst system. The alkynylsilanes bearing hydrosilyl moieties provide an opportunity for further functionalization (e. g., hydrosilylation). The use of primary silanes as substrates and precatalyst activators permits the use of inexpensive and easily accessible 3d metal precatalysts, and avoids the presence of additional activators

Silane-modified surfaces in specific antibody-mediated cell recognition

The immobilization of antibodies on various surfaces has been the subject of advanced research in various immunoassay-based diagnostic devices. The physical and chemical stabilities of the immobilized antibodies on a solid surface still cause many problems because upon immobilizing antibody molecules, the antigen-binding ability usually decreases. The silanization of surfaces with organosilanes carrying chemically active groups such as (3-aminopropyl) triethoxysilane (APTES) can accommodate these antigen-binding molecules in an appropriate orientation so that their functionality and binding activity are essentially retained. In this study, n-butyltrimethoxysilane (BMS) and 3-(octafluoropentyloxy)-propyltriethoxysilane (OFPOS) were used as “blocking silanes”. The aims of this study were to compare the effectiveness of specific antibody binding of APTES, APTES + BMS and APTES + OFPOS and to characterize the modified surfaces by contact angle measurements and immunofluorescence measurements prior to and after immobilizing proteins. Additionally, we have evaluated the functionality of the immobilized antibodies by their abilities to bind EpCAM-positive human colon adenocarcinoma cell line (LoVo) and EpCAM-negative mouse embryonic fibroblast cell line (3T3). Cell enumeration was conducted on the basis of DAPI-positive signals and recorded using a confocal laser scanning biological microscope. The results of our study showed that the immobilization capability and reactivity of APTES, APTES + BMS and APTES + OFPOS differ. The modification of APTES with unreactive silanes (BMS,OFPOS) is recommended to improve the antibody binding efficiency. However, using OFPOS resulted in more effective antibody and cell binding, and it appears to be the most useful compound in specific antibody-mediated cell recognition

Catalytic methods for the synthesis of unsymmetrical siloxanes

Silicon-oxygen moiety (Si-O) is one of the most important chemical scaffolds, starting with its role in nature as a major constituent of Earth’s crust, and finishing on its usefulness in terms of a broadly understood practicability for the industry. This second issue refers primarily to siloxanes including both short and long- chained derivatives. To date, the classical condensation between different O-nucleophiles (e.g., water, alcohols, silanols, etc.) and halosilanes appears to be the most useful, large-scale method for their obtainment. However, the issues related to low chemoselectivity and low sustainability of these processes have caused an extensive exploration of more selective and milder alternatives. Herein, several methods for the formation of unsymmetrical siloxanes are discussed including these based on the cleavage of silicon-hydrogen or silicon- carbon bonds in the presence of silanols and proper catalysts/mediators

Data from: Pseudo-enantiomeric chiral components and formation of the helical micro- and nanostructures in charge-transfer complexes

Helical organic micro- and nanostructures are formed by a charge-transfer complex, cinchonidine-TCNQ. These unusual forms result from the chirality, the steric structure and specific interactions of cinchonidine molecules . The material is semi-conducting (10-4 S/cm), with the typical absorption spectra in IR and UV-VIS, but also a characteristic CD spectrum. Surprisingly, conductive micro- and nano helices are not formed in the case of pseudo- enantiomeric cinchonine, i.e. the complex of cinchonine and TCNQ

HEED1

HEED

CND-TCNQ5

CND-TCNQ

CND-TCNQ3

CND-TCNQ