TY - JOUR

T1 - IR-Spectroscopic Evidence for Acetonitrile Interaction with Carbenium Ions in Zeolites

AU - Bystrov, D. S.

AU - Tsyganenko, A. A.

AU - Forster, H.

PY - 1993/1/1

Y1 - 1993/1/1

N2 - The chapter discusses whether the high-frequency band of the C= N vibration is really due to the species formed as a result of acetonitrile interaction with the products of propene adsorption or should it belong to the nitrile molecules coordinated to A13+ Lewis acid sites. It is known for the complexes of acetonitrile with BHal3 compounds that the C=N stretching fundamental band reveals small but detectable shifts from about 1 up to 3 cm−1 after 10B by 11B substitution. This means that upon using isotopically substituted propene, a shift of the nitrile band should be expected due to the strong interaction of the C= N group with carbocations. For this purpose, in the study described in the chapter the infrared (IR) spectra of CD3CN adsorbed on HZSM-5 zeolite pretreated with both normal propene and propene-d6 were investigated at 300 K. The observed sensitivity of the CN frequency to isotopic substitution in propene leads to the conclusion that the nitrile C=N group of the resulting product is really bound to the positively charged C atom of propene but not to the Al3+ ion of the zeolite framework.

AB - The chapter discusses whether the high-frequency band of the C= N vibration is really due to the species formed as a result of acetonitrile interaction with the products of propene adsorption or should it belong to the nitrile molecules coordinated to A13+ Lewis acid sites. It is known for the complexes of acetonitrile with BHal3 compounds that the C=N stretching fundamental band reveals small but detectable shifts from about 1 up to 3 cm−1 after 10B by 11B substitution. This means that upon using isotopically substituted propene, a shift of the nitrile band should be expected due to the strong interaction of the C= N group with carbocations. For this purpose, in the study described in the chapter the infrared (IR) spectra of CD3CN adsorbed on HZSM-5 zeolite pretreated with both normal propene and propene-d6 were investigated at 300 K. The observed sensitivity of the CN frequency to isotopic substitution in propene leads to the conclusion that the nitrile C=N group of the resulting product is really bound to the positively charged C atom of propene but not to the Al3+ ion of the zeolite framework.

UR - http://www.scopus.com/inward/record.url?scp=77956928568&partnerID=8YFLogxK

U2 - 10.1016/S0167-2991(08)64495-X

DO - 10.1016/S0167-2991(08)64495-X

M3 - Article

AN - SCOPUS:77956928568

VL - 75

SP - 1623

EP - 1624

JO - Studies in Surface Science and Catalysis

JF - Studies in Surface Science and Catalysis

SN - 0167-2991

IS - C

ER -