Weight Of Halogen Research Articles

5600050 Zeolite catalyst for the liquid phase alkylation and transalkylation of benzene

Disclosed is a modified zeolite catalyst for the liquid phase alkylation and transalkylation of benzene comprising 30 to 70% by weight of H-beta zeolite with a silicon to aluminium ratio of 20 to 40; 0.5 to 10% by weight of halogen; and γ-Al 2 O 3 of the balance. Also disclosed a method for preparing the said catalyst comprising adding a halogen-containing compound to a mixture of H-beta zeolite and a precursor of γ-Al 2 O 3 , forming followed by calcining.

The intramolecular NH···Cl hydrogen bond in urea derivatives containing the o-chlorophenyl group

The solution v(N-H) vibrations of various disubstituted ureas containing a halophenyl group have been examined in order to directly confirm the presence of an intramolecular NH···Cl hydrogen bond in the o-chloro analog. In chlorophenyl derivatives the v(N-H) band for the N-H bond adjacent to an o-chlorophenyl group is always lower than that for a N-H bond adjacent to a phenyl, m- or p-chlorophenyl group. The corresponding band in N-o-halophenyl- N'-phenylureas, o-XPhUPh [U = HNC(O)NH], shifts to significantly lower wavenumber with increasing atomic size or weight of halogen. The o-XPhUPh derivatives are concluded to be in two intramolecularly NH···X hydrogen-bonded forms with N-H trans or cis to the CO group.