Application of Hydrazine Hydrate in the Synthesis of Octa(aminophenyl)silsesquioxane (OAPS) Poss

Abstract

Octa(aminophenyl)silsesquioxane (OAPS) was prepared from octaphenyl silsesquioxane (OPS) in two steps, first nitration to obtain Octa(nitrophenyl)silsesquioxane (ONPS) then reduction by using the stable, inexpensive, and readily available hydrazine hydrate as the reducing agent in the presence of Iron(III)Chloride catalyst with a yield of around 87%. Hydrazine is a two-electron reducing agent whereas nitro group is a four-electron reduction process. The activated carbon serves as an adsorbent and electrical conductor enabling the reaction to occur by acting as a mediator between a two-electron reagent and a four-electron process. Adsorption provides a reducing potential and a supply of electrons from many hydrazines making possible the initial four-electron process even though each individual hydrazine is a two-electron donor. The product was characterized by FTIR and 1 H NMR. The time period for preparation of ONPS from octaphenyl silsesquioxane was considerably shortened to avoid double nitration of the aromatic rings.

High-temperature molecular screening of hybrid polyOAPS-imide networks based on octa(aminophenyl)silsesquioxane for increased thermomechanical resistance

“…The main synthesis route for OAPS is by nitration of octaphenylsilsequioxane (OPS) to first form octa(nitrophenyl)silsesquioxane (ONPS), followed by a reduction to transform the -NO 2 into -NH 2 groups. 33,41,42 It was first reported that this synthesis led to a mixture of 50% of the meta isomer and 50% of the para isomer without any ortho substitution. 33 This was later confirmed by several groups.…”

“…48 This approach is thus able to better control the proportions of the isomers but its downside is that, up to now, the cage sizes seem to be less well controlled than in the nitration/reduction route from OPS to OAPS. 33,41,42 In the present molecular screening work, the goal is to clearly assess the effects of the various isomers and their resistance under harsh conditions. As such, the metaOAPS, paraOAPS and orthoOAPS were all considered as separate inorganic precursors along with the PMDA, 6FDA and ODPA dianhydrides as organic precursors.…”

Brush-like Polymer Prodrug with Aggregation-Induced Emission Features for Precise Intracellular Drug Tracking

“…These four bands mainly originated from PEGA [ 41 ]. Two bands at 1350 and 1240 cm −1 are related to the symmetric and asymmetric C-N stretching vibration of the hydrazine component [ 42 ]. A slightly weak band at 1450 cm −1 might be related to the aromatic C-H stretching vibration and a weak band at 945 cm −1 could be related to the C=C bending vibration.…”

Molecular Characterization of Membrane Gas Separation under Very High Temperatures and Pressure: Single- and Mixed-Gas CO2/CH4 and CO2/N2 Permselectivities in Hybrid Networks

“…To our knowledge, this route has only been explored once for OAPS, using separately the meta and para isomers of aminophenyltrialkoxysilanes [ 49 ]. It does lead to isomer-specific OAPS, but the cage sizes are not as well controlled as in the nitration/reduction route [ 38 , 44 , 49 , 50 ]. The OAPS under study in this paper are based on the silane precursor route, i.e., each of the three isomers is considered separately in its pure form ( Figure 1 a) in order to clearly assess the effects of the substitution position.…”