Intercalation behaviors of chiral titanium(IV) (triethanolaminato)-isopropoxide (Ti(C2H4O)3N(OCH(CH3)2) in protonated lamellar metal oxides and characterization of the intercalated resultants

Abstract

The intercalation behaviors of chiral titanium(IV) (triethanolaminato)-isopropoxide (the chemical formula is Ti(C 2 H 4 O) 3 N(OCH(CH 3 ) 2 ), abbreviated as TEAIP) in a series of layered protonated metal oxides (HNb 3 O 8 , HTiNbO 5 , HLaNb 2 O 7 , H 2 Ti 4 O 9 and H 2 Ti 2.8 Mn 0.2 O 7 ) were investigated. TEAIP could be intercalated into the interlayer spaces of layered HNb 3 O 8 as well as HTiNbO 5 , and as a result, two novel inorganic-organic hybrid nanocomposites, TEAIP-intercalated HNb 3 O 8 and TEAIP-intercalated HTiNbO 5 , were obtained,respectively. Based on the compositions of the intercalated compounds quantitatively estimated from TG-DTA data, the chemical formulas of the TEAIP-intercalated HNb 3 O 8 and TEAIPintercalated HTiNbO 5 were expressed as (TEAIP) 0.17 H 0.83 Nb 3 O 8 and (TEAIP) 0.14 H 0.86 TiNbO 5 , respectively. Neither H 2 Ti 4 O 9 nor H 2 Ti 2.8 Mn 0.2 O 7 formed any intercalated phase through the exchange reaction between the layered protonated metal oxides and TEAIP; HLaNb 2 O 7 could only accommodate a very limited amount of the guest molecules, giving rise to a TEAIP-partially intercalated layered product. The different intercalation behavior of TEAIP in the layered metal oxides was ascribed to the difference of these protonated metal oxides in acidity and the difference of the layered hosts in charge density. The competitively intercalation behavior between TEAIP and n-decylamine in the interlayer space of HNb 3 O 8 as well as HTiNbO 5 was also investigated. Both TEAIP and n-decylamine could be simultaneously intercalated into HNb 3 O 8 , leading to two different guest-intercalated phases, although n-decylamineintercalated phase was thermally unstable compared with the TEAIP-intercalated phase. In the case of HTiNbO 5 , only ndecylamine-intercalated phase was formed. The different basicity and steric hindrance of the two kinds of guest molecules and different acidity of the two layered hosts were mainly responsible for the above results.