期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1974
卷号:71
期号:8
页码:2961-2964
DOI:10.1073/pnas.71.8.2961
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A comparison of the 13C nuclear magnetic resonance chemical shifts of some 15,16-dialkyl-15,16-dihydropyrenes with the corresponding 15,16-dialkyl-2,7,15,16-tetrahydropyrenes provides a measure of the effect of ring current on carbon-13 chemical shifts in which other effects may be expected to be negligibly small. The general conclusion is that the absolute magnitude of the ring-current effect is the same for carbon-13 as for protons when they occupy the same position in space relative to the aromatic {pi}-electron cloud.