Synthesis – properties correlation and the unexpected role of the titania support on the Grignard surface modification

Experimental and computational insights into the aminopropylphosphonic acid modification of mesoporous TiO2 powder: The role of the amine functionality on the surface interaction and coordination

“…[19][20][21][22] Different precursors can be used for grafting transition metal oxides such as organosilanes, organophosphonic acids, carboxylic acids, alcohols and Grignard reagents. 23,24,25,26 Whereas organosilanes are the most applied precursors for surface grafting, in particular for SiO2, they are less applicable to TiO2 and ZrO2, as the poor hydrolytic stability of Ti-O-Si and Zr-O-Si bonds results in a rapid leaching of the organic layer. 27 Grafting long, hydrophobic functional groups and ensuring full surface coverage increases the stability, but reduces to some extent the tailoring of the surface properties relative to other grafting methodologies and limits the applicability of such materials.…”

Inducing differences in modification degree and binding mode of organophosphonic acid grafted titania by changing pH and hydrocarbon chain length

“…TiO2 P25 was purchased from Sigma-Aldrich (catalog number: 718467-100G, ≥ 99.5 %) and used without pretreatment. P25 consists of ~83 % anatase, ~13 % rutile, and ~4 % amorphous fraction as characterized by electron energy loss spectroscopy (EELS) [40]. A BET (Brunauer-Emmett-Teller) surface area of 51 m²/g was obtained with nitrogen sorption at -196 °C using a Quantachrome Quadrasorb automated sorption system.…”

“…In order to gain further insight into the link between these interactions, the NH2/NH3 + ratio and their correlation with the phosphorus environments as a function of chain length, DFT calculations were performed. Since the dominant crystal surface of anatase is the (101) crystal facet and anatase accounts for about 83% of P25 [40], [71], [72], the DFT calculations were which are considerably longer (mode 3); this fact may be used to explain the higher relative energy (46.3 kJ/mol) of the latter mode. On the other hand, the nitrogen atom in the NH2 groups can also coordinate to surface Ti sites using its lone pair to form a Lewis acid-base interaction (Ti•••NH2).…”

Amino-Alkylphosphonate-Grafted TiO2: How the Alkyl Chain Length Impacts the Surface Properties and the Adsorption Efficiency for Pd

“…Developments in non-siliceous transition-metal oxides (TiO 2 , ZrO 2 , Al 2 O 3 , ITO) are of increasing interest in various research domains. − Especially, TiO 2 is studied extensively due to its synthesis possibilities that offer a wide variety of nano-morphologies, crystal facet engineering, and the broad field of application domains such as (photo)­catalysis, photovoltaic devices, and biosensing. − For several applications where the performance is governed by surface interactions, such as separation and sorption processes, the native surface chemistry (Ti–O–Ti and Ti–OH groups) limits the diversity and specificity of interactions with the environment. , Post-synthesis surface modification (i.e., grafting) with organic groups is known as a viable strategy to tune and control these surface properties given their large versatility in functional properties. Different precursors have been studied for surface grafting, such as alcohols, carboxylic acids, organosilanes, organophosphonic acids and their derivatives, and Grignard reagents. − …”

“…Different precursors have been studied for surface grafting, such as alcohols, carboxylic acids, organosilanes, organophosphonic acids and their derivatives, and Grignard reagents. 13 − 15 …”