(CROSS-CONJUGATED DIENYL)TRICARBONYLIRON CATIONS .2. 4-METHYL DERIVATIVES

被引:25
作者
BONAZZA, BR [1 ]
LILLYA, CP [1 ]
MAGYAR, ES [1 ]
SCHOLES, G [1 ]
机构
[1] UNIV MASSACHUSETTS,DEPT CHEM,AMHERST,MA 01003
关键词
D O I
10.1021/ja00509a016
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Tricarbonyl(cross-conjugated dienyl)iron cations have been generated from precursor alcohols in strong acid solutions and studied by NMR spectroscopy in the temperature range 0 to -50°C. The 4-anti-methyl cation (11) coordinates reversibly, but slowly, with fluorosulfonate ion to give the adduct 12. Broadening of1H and13C NMR signals in the region -40 to -9°C demonstrates rotation about the C2-C3bond of 11. The observations exclude 12 as an intermediate in the rotation process. Relief of steric strain associated with the 4-anti-methyl enhances the driving force for FS03coordination and lowers the barrier for C2-C3rotation. The 4-syn-methyl cation (15) does not give a fluorosulfonate adduct and fails to exhibit NMR signal broadening caused by C2-C3rotation at temperatures below 0°C. Neither cation coordinates with carbon monoxide. Lack of evidence of coordinative unsaturation and the substantial barrier to C2-C3rotation rule out the η3-allyl type structure predicted by the simplest (one interaction) frontier orbital model. © 1979, American Chemical Society. All rights reserved.
引用
收藏
页码:4100 / 4106
页数:7
相关论文
共 52 条
[51]   RAPID INTRAMOLECULAR REARRANGEMENTS IN PENTACOORDINATE TRANSITION-METAL COMPOUNDS .5. COUPLING OF OLEFIN ROTATION AND BERRY PSEUDOROTATION IN TETRACARBONYLIRON-OLEFIN COMPLEXES [J].
WILSON, ST ;
COVILLE, NJ ;
SHAPELY, JR ;
OSBORN, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1974, 96 (12) :4038-4040
[52]   DIPROTONATION AND TAUTOMERISM IN OLEFIN-IRON CARBONYL COMPLEXES [J].
YOUNG, DAT ;
HOLMES, JR ;
KAESZ, HD .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1969, 91 (25) :6968-&