C-13 CP/MAS AND H-2 NMR-STUDY OF TERT-BUTYL ALCOHOL DEHYDRATION ON H-ZSM-5 ZEOLITE - EVIDENCE FOR THE FORMATION OF TERT-BUTYL CATION AND TERT-BUTYL SILYL ETHER INTERMEDIATES

被引:85
作者
STEPANOV, AG [1 ]
ZAMARAEV, KI [1 ]
THOMAS, JM [1 ]
机构
[1] UCL ROYAL INST GREAT BRITAIN, DAVY FARADAY RES LAB, LONDON W1X 4BS, ENGLAND
关键词
TERT-BUTYL ALCOHOL; DEHYDRATION; H-ZSM-5; ZEOLITE; TERT-BUTYL CATION; TERT-BUTYL SILYL ETHER; MECHANISM OF REACTION;
D O I
10.1007/BF00765044
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The dehydration reaction of tert-butyl alcohol, selectively labelled with C-13 in CH3 or C-O groups (t-BuOH[2-C-13(1)] and t-BuOH[1-C-13]), as well as selectively deuterated in methyl groups (t-BuOH[2-H-2(9)]), was studied on H-ZSM-5 zeolite simultaneously with C-13 CP/MAS and H-2 solid state NMR. When adsorbed and dehydrated on zeolite at 296 K, t-BuOH[2-C-13(1)] and t-BuOH[1-C-13] give rise to identical C-13 CP/MAS NMR spectra of oligomeric aliphatic products. This is explained in terms of the fast isomerization of the tert-butyl hydrocarbon skeleton via the formation of tert-butyl cation as the key reaction intermediate. An alkoxide species, most probably tert-butyl silyl ether (t-BuSE), was also detected as the "side" reaction intermediate. This intermediate was stable within the temperature range 296-373 K and decomposed at 448 K to produce additional amounts of final reaction products, i.e. butene oligomers. NMR data point to the existence of equilibria between the initial tert-butyl alcohol, tert-butyl cation and butene that is formed from the intermediate carbocation.
引用
收藏
页码:407 / 422
页数:16
相关论文
共 17 条
[1]   AN INFRARED-SPECTROSCOPY STUDY OF SIMPLE ALCOHOLS ADSORBED ON H-ZSM-5 [J].
ARONSON, MT ;
GORTE, RJ ;
FARNETH, WE .
JOURNAL OF CATALYSIS, 1987, 105 (02) :455-468
[2]   C-13 NMR IDENTIFICATION OF INTERMEDIATES FORMED BY 2-METHYL-2-PROPANOL ADSORPTION IN H-ZSM-5 [J].
ARONSON, MT ;
GORTE, RJ ;
FARNETH, WE ;
WHITE, D .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (03) :840-846
[3]  
Farrar Th., 1971, INTRO THEORY METHODS
[4]  
GORDON AJ, 1976, CHEM COMPANION HDB P, P127
[5]   REACTIONS OF PROPENE ON ZEOLITE HY CATALYST STUDIED BY INSITU VARIABLE-TEMPERATURE SOLID-STATE NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPY [J].
HAW, JF ;
RICHARDSON, BR ;
OSHIRO, IS ;
LAZO, ND ;
SPEED, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (06) :2052-2058
[6]  
MAKAROVA MA, COMMUNICATION
[7]   QUANTUM-CHEMICAL CALCULATIONS OF C-13 CHEMICAL-SHIFTS OF THE ALKOXIDE FORM IN ZEOLITES [J].
MALKIN, VG ;
CHESNOKOV, VV ;
PAUKSHTIS, EA ;
ZHIDOMIROV, GM .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1990, 112 (02) :666-669
[8]  
MYHRE PC, 1981, J AM CHEM SOC, V103, P203
[9]   STABLE CARBOCATIONS .208. C-13 NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPIC STUDY OF ALKYL CATIONS - CONSTANCY OF C-13 NUCLEAR MAGNETIC-RESONANCE METHYL SUBSTITUENT EFFECTS AND THEIR APPLICATION IN STUDY OF EQUILIBRATING CARBOCATIONS AND MECHANISM OF SOME REARRANGEMENTS [J].
OLAH, GA ;
DONOVAN, DJ .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1977, 99 (15) :5026-5039
[10]   REACTIONS OF BUTADIENE IN ZEOLITE CATALYSTS BY INSITU VARIABLE-TEMPERATURE SOLID-STATE NUCLEAR-MAGNETIC-RESONANCE SPECTROMETRY [J].
RICHARDSON, BR ;
LAZO, ND ;
SCHETTLER, PD ;
WHITE, JL ;
HAW, JF .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1990, 112 (08) :2886-2891