From the fundamental to the applied: Elucidating the reduction chemistry of tris-(trialkylsiloxide)tantalum; building inorganic-organic-inorganic interfaces; and pondering ethical problems in science.

摘要

Various sized siloxides were used to make (siloxide)3TaCl 2. Product analyses of sodium amalgam reductions of several dichlorides suggest that a mu-chloride dimer may be a common intermediate in the reduction pathway. When the siloxide is large (tBu3SiO), formation of the Ta(III) species, (tBu3SiO)3Ta, occurs via disproportionation. When the siloxide is small, the Ta(IV) intermediate is stable (e.g., [(iPr3SiO)3Ta] 2(mu-Cl)2 (1.2-iPr3)) and when intermediate sized siloxides are used, solvent bond activation via unstable Ta(III) tris-siloxides is proposed to occur. Under hydrogen, reductions of 1.1-Me and 1.1-Ph provide Ta(IV) and Ta(V) hydrides [(tBu2MesiO)3Ta]2(mu-H) 2 (1.4-Me) and (tBu2PhSiO) 3TaH2 (1.7-Ph), respectively.;A series of rigid monomers, bearing a thiophene "head" group and a reactive "tail group" (either N-alkylaniline or phenol) were synthesized for self assembly on a Au(1,1,1) surface. SAMs were made by exposing these monomers to a Au(1,1,1) substrate and their properties were studied by XPS, ellipsometry and contact angle spectroscopy. The results showed that the monomers (2.6 and 2.7) form SAMs on Au (t,1,1) and that the tilt angle and surface density of these SAMs depends on the number of conjugated aromatic units in the monomer's backbone. After self-assembly, the SAMs (2.6-iPr and 2.7iPr ) were treated with Ti(NMe2)4 and were shown to reaction with ½ equiv of Ti(NMe2)4 Per SAM.;Nickel(II) triflate was treated with 2-phenylpyridine under thermolytic conditions and shown to perform C-H bond activation to generate 3.1 , a monocyclometallated species. Treatment of 3.1 with KOtBu resulted in the rapid generation of 3.2, the double cyclometallated species.;The concept of "idea misappropriation" was studied within the scope of scientific research proposals. Confusion over the concept of ownership, as it pertains to ideas, as well as the open versus closed nature of the peer review process were determined to be important factors affecting the instances of misappropriation.