NUCLEAR-SPIN SPIN COUPLING VIA NONBONDED INTERACTIONS .4. F-F AND H-F COUPLING IN SUBSTITUTED BENZO[C]PHENANTHRENES
NUCLEAR-SPIN SPIN COUPLING VIA NONBONDED INTERACTIONS .4. F-F AND H-F COUPLING IN SUBSTITUTED BENZO[C]PHENANTHRENES
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DOI：
10.1021/jo00204a006
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发表时间：
1985-01-01
影响因子：
3.6
通讯作者：
RICKER, WM
中科院分区：
文献类型：
--
作者：
MALLORY, FB;MALLORY, CW;RICKER, WM
本文报道了一系列4-取代1，12-二氟苯并[c]-菲的FF偶合常数的NMR测定。结果提供了进一步的支持早期的概括，分子内的“通过空间”FF耦合，相反，其“通过键”的对应物，基本上是不敏感的取代基的电子特性，即使他们造成显着的扰动19 F化学位移。对于几种4-和9-取代的1-氟苯并[c]菲，H-12和Fl之间的大幅度“穿透空间”HF偶联显示出对取代基的类似不敏感性。这是一致的概念，“通过空间”HF和FF耦合有类似的起源在非键重叠相互作用。
NMR measurements of the FF couplingconstants for a series of 4-substituted l, 12-difluorobenzo [c]-phenanthrenes are reported. The results provide further support for earlier generalizations that intramolecular “through-space” FF coupling, in contrast to its “through-bond” counterpart, is essentially insensitive to the electronic character of substituents even though they cause significant perturbations in the 19F chemical shifts. The large magnitude “through-space” HF coupling between H-12 and Fl for several 4-and 9-substituted 1-fluorobenzo [c] phenanthrenes shows a similar insensitivity to substituents. This is consistent with the notion that “through-space” HF and FF coupling have analogous origins in nonbonded overlap interactions.