Abstract
The photocatalysed reaction of five selected organic systems, namely 2,2′-dinitro biphenyl (
1),
N,
N′-dimethyl-4-nitroso aniline (
2), 4-dimethyl amino benzaldehyde (
3), phthalaldehyde (
4) and tetramethyl benzoquinone (
5) has been investigated in acetonitrile/water mixture in the presence of titanium dioxide and oxygen. An attempt has been made to identify the products formed during the photooxidation process through GC/MS analysis technique. The photolysis of 2,2′-dinitro biphenyl (
1) leads to the formation of 2-hydroxy-2′-nitro biphenyl (
6), 2,2′-dihydroxy biphenyl (
7) and 2-biphenyl amine (
11); whereas,
N,
N′-dimethyl-4-nitroso aniline (
2) gave rise to
N,
N′-dimethyl-4-nitro aniline (
14) and
N,
N′-dimethyl-1,4-benzenediamine (
15). However, the photolysis of 4-dimethyl amino benzaldehyde (
3) yielded only a demethylated product (
18). The illumination of phthalaldehyde (
4), on the other hand, led to the formation of two products such as 1(3H)-isobenzofuranone (
24) and 2-formyl-benzoic acid (
21). Two intermediate products, tetramethyl hydroquinone (
35) and 2,5-furandione-3,4-dimethyl (
34) have been identified in case of tetramethyl benzoquinone (
5). The products have been identified by comparing the molecular ion and mass fragmentation peaks of the products with those reported in the GC/MS library. A probable mechanism for the formation of the products has been proposed.