Solid solutions for cleaning up chemical processes using hydrogen peroxide

Terminal Titanyl Complexes of Tri- and Tetrametaphosphate: Synthesis, Structures, and Reactivity with Hydrogen Peroxide

“…Experimental details and characterization data for all compounds including crystallographic information for [ [3], and [PPN] 2 [4] are provided in the Supporting Information. This material is available free of charge via the Internet at http://pubs.acs.org.…”

“…15,28 The formation of 1 and 2 from [OTi(acac) 2 ] 2 is noteworthy in illustrating that the tri-and tetrametaphosphates are capable of breaking up the titanium(IV) bis-µ-oxo core of [OTi(acac) 2 ] 2 to result in the formation of terminal Ti≡O units. Titanium(IV) oxo species are typically susceptible to hydrolysis in the presence of moist air as they have the propensity to dimerize and oligomerize forming unreactive species containing Ti-O-Ti linkages, 3,29 so the formation of a well-defined, air-stable terminal titanyl complex is unusual.…”

“…50 We were unable to observe a stable titanium(IV) hydroperoxo complex, and 1 and 2 did not show any signs of catalytic activity toward organic substrates in the presence of We did, however, test the ability of 3 and 4 to behave as stoichiometric oxidants towards phosphorus(III) compounds and sulfides. Treatment of 3 with P(OMe) 3 , PPh 3 and SMe 2 at ambient temperature resulted in the formation of the corresponding organic oxide as well as clean regeneration of 1 as determined by 31 12 were prepared as previously reported. All reagents were purchased from Sigma Aldrich (urea⋅H 2 O 2 , [OTi(acac) 2 ] 2 , 30% H 2 O 2 ), or Gelest (Me 3 SiOOSiMe 3 ) and used as received.…”

“…Large diffraction quality orange crystals grew over the course of 12 h. The pale orange mother liquor was removed and the crystals were dried under reduced pressure to afford analytically pure Alternative preparation using (SiMe 3 ) 2 O 2 . In the fumehood, to a stirring solution of [PPN] 2 [3] (100 mg, 0.0677 mmol, 1.00 eq) in MeCN (5 mL) was added (SiMe 3 ) 2 O 2 (22 µL, 0.10 mmol, 1.5 eq) via 50 µL microsyringe. The color of the solution gradually changed from colorless to bright orange over the course of 12 h, at which point the reaction mixture was concentrated to ca.…”

“…2 In heterogeneous systems, these issues are circumvented through site isolation of discrete metal oxos within inorganic matrices that function as thermodynamically stable ligand environments. 3,4 An example of one such system is EniChem's highly efficient TS-1 oxidation catalyst, 5,6 a titanium-based microporous molecular sieve in which Ti(IV) ions are isolated within an entirely silicate based framework. 7 The success of TS-1 and other industrial oxidation catalysts has driven synthetic chemists to study molecular models of heterogeneous systems.…”