B. Ohtani et al., PHOTOCATALYTIC TRANSFER HYDROGENATION OF SCHIFF-BASES WITH PROPAN-2-OL BY SUSPENDED SEMICONDUCTOR PARTICLES LOADED WITH PLATINUM DEPOSITS, Journal of the Chemical Society. Faraday transactions, 92(21), 1996, pp. 4291-4295
Citations number
35
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Photoirradiation at >300 nm of platinized titanium(IV) oxide (TiO2-Pt)
or cadmium(II) sulfide loaded with platinum(IV) oxide suspended in pr
opan-2-ol has been shown to lead to transfer hydrogenation of Schiff b
ases [N-benzylidenebenzylamine (BdBA) and N-benzylideneaniline] to the
corresponding secondary amines [dibenzylamine (DBA) and N-benzylanili
ne, respectively]. Dehydrogenation of propan-2-ol also occurred as a s
ide reaction. The transfer hydrogenation required both the photoirradi
ation and suspended semiconductor particles, indicating that photoexci
ted electrons and positive holes induces the reaction. Platinization o
f the semiconductor particles was also necessary and TiO2-Pt prepared
by impregnation followed by H-2 reduction showed the highest yield of
DBA from BdBA. The most efficient catalyst was prepared by reduction a
t an H-2 flow rate of 35 cm(3) min(-1) and had small Pt deposits dispe
rsed uniformly on each TiO2 particle. Addition of molecular sieve 3A t
o the reaction mixture improved the selectivity to DBA from BdBA by ab
sorbing contaminant water and thereby inhibiting the hydrolysis of BdB
A and subsequent formation of N-benzylpropyl-2-amine.