While the formation and breaking of transition metal (TM)-carbon bonds plays a pivotal role in the catalysis of organic compounds, the reactivity of inorganometallic species, that is, those involving the transition metal (TM)-metalloid (E) bond, is of key importance in most conversions of metalloid derivatives catalyzed by TM complexes. This Review presents the background of inorganometallic catalysis and its development over the last 15 years. The results of mechanistic studies presented in the Review are related to the occurrence of TM-E and TM-H compounds as reactive intermediates in the catalytic transformations of selected metalloids (E = B, Si, Ge, Sn, As, Sb, or Te). The Review illustrates the significance of inorganometallics in catalysis of the following processes: addition of metalloid-hydrogen and metalloid-metalloid bonds to unsaturated compounds; activation and functionalization of C-H bonds and C-X bonds with hydrometalloids and bismetalloids; activation and functionalization of C-H bonds with vinylmetalloids, metalloid halides, and sulfonates; and dehydrocoupling of hydrometalloids. This first Review on inorganometallic catalysis sums up the developments in the catalytic methods for the synthesis of organometalloid compounds and their applications in advanced organic synthesis as a part of tandem reactions.
Hydrophobization of cotton fabrics was carried out with the use of bifunctional polysiloxanes with various contents of functional groups. Polysiloxanes contained in their structure groups capable of bonding to substrates (trialkoxysilyl or glycidyl ones) and fluoroalkyl groups showing surface activity. Two methods of surface modification were compared: (1) a one-step method via the chemical modification of fabrics with solutions of bifunctional polysiloxanes and (2) a two-step method—via preliminary modification of fabrics with silica sol followed by chemical modification with solutions of bifunctional polysiloxanes. The hydrophobicity was determined by measuring the water contact angle by drop profile tensiometry. Changes in the surface topography were examined by scanning electron microscopy. Superhydrophobic fabrics were obtained by a simple one-step method by the chemical modification in solutions of bifunctional polysiloxanes. The fabrics maintained their superhydrophobic properties even after multiple washings. The modification does not cause any changes visible to the naked eye, such as stiffening, color changes or a decrease in mechanical properties.
Innovative materials were made via the combination of chitin and lignin, and the immobilization of lipase from Aspergillus niger. Analysis by techniques including FTIR, XPS and 13C CP MAS NMR confirmed the effective immobilization of the enzyme on the surface of the composite support. The electrokinetic properties of the resulting systems were also determined. Results obtained from elemental analysis and by the Bradford method enabled the determination of optimum parameters for the immobilization process. Based on the hydrolysis reaction of para-nitrophenyl palmitate, a determination was made of the catalytic activity, thermal and pH stability, and reusability. The systems with immobilized enzymes were found to have a hydrolytic activity of 5.72 mU, and increased thermal and pH stability compared with the native lipase. The products were also shown to retain approximately 80% of their initial catalytic activity, even after 20 reaction cycles. The immobilization process, using a cheap, non-toxic matrix of natural origin, leads to systems with potential applications in wastewater remediation processes and in biosensors.