Knizek J.,Butenandtstrasse |
Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences | Year: 2011
Bis[tri(tert.-butyl)silanolato]tantalum(V) trichloride reacts with LiMe to give trimethyl-bis[tri(tert.-butyl)silanolato]tantalum(V), 6. Its molecular structure shows a trigonal-bipyramidal coordination of the Ta atom with the Me groups in the equatorial plane. Its reaction with catecholborane produces preferably B-methyl-catecholborane besides some phenylene-1,2-dioxo-bis(1,3,2- dioxaboro-lane), 9, and H 3B · THF. Similarly, the reaction of 6 with dimeric 9-borabicyclononane (9-BBN) generates preferable tri(tert.-butyl)siloxy-9-BBN (75 %) and Me-9-BBN (25 %). In contrast, cleavage of the Ta-O bonds is the preferred route in the treatment of 6 with H 3B · THF. 11B NMR shows the formation of (tBu 3SiO) 2BH and (tBu 3SiO) 3B or (tBuSiO) 3B 3O 3. No tantalum hydride could be isolated.
Pust P.,Butenandtstrasse |
Pagano S.,Butenandtstrasse |
European Journal of Inorganic Chemistry | Year: 2013
Ca[LiAlN2] was synthesized from LiAlH4, LiN 3, calcium, and lithium metal as fluxing agent in welded-shut tantalum crucibles at 900 °C. The compound crystallizes in the form of transparent colorless platelets that undergo hydrolysis in air and under moisture. The crystal structure [P21/c (no. 14), a = 5.7587(12) Å, b = 6.8773(14) Å, c = 5.7960(12) Å, β = 90.28(3)°, Z = 4] was solved from single-crystal X-ray diffraction data and was confirmed with Rietveld refinement methods and lattice-energy calculations (Madelung part of lattice energy, MAPLE). Ca[LiAlN2] forms layers of edge- and vertex-sharing AlN4 tetrahedra isotypic with LiCaGaN2. Li+ ions are positioned in tetrahedral voids within the [Al 2N2N4/2] layers resulting in a highly condensed structure of Al- and Li-centered polyhedra. Ca[LiAlN2] was synthesized by high-temperature synthesis using flux techniques. It represents the first example of a quaternary calcium lithionitridoaluminate with tetrahedral AlN4 and LiN4 units. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Schlossbauer A.,Ludwig Maximilians University of Munich |
Dohmen C.,Butenandtstrasse |
Schaffert D.,Butenandtstrasse |
Wagner E.,Butenandtstrasse |
Bein T.,Ludwig Maximilians University of Munich
Angewandte Chemie - International Edition | Year: 2011
Free to go: A pH-labile immobilization of the melittin peptide with acetal linkers in the pore system of a SBA-15 host allows release of the peptide upon decrease of the pH value from 7.4 to 5.5. Such a release is shown by melittin-induced lysis of mouse erythrocytes. The method could be used to prepare new silica-based peptide delivery systems for targeted cancer therapy. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.