Carbon chemical shift tensor components in quinolines and quinoline N-oxides.
Carbon chemical shift tensor components in quinolines and quinoline N-oxides.
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喹啉和喹啉 N-氧化物中的碳化学位移张量成分。
DOI：
10.1021/jp055372e
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
deDios,AngelC
中科院分区：
文献类型：
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作者：
Casabianca,LeahB;Faller,CaitlynM;deDios,AngelC
本文对1，8-二（2-异丙基-4-喹啉基）萘、2-异丙基喹啉、阿莫地喹、氯喹和奎宁中喹啉碳及其N-氧化物进行了化学位移计算。从头计算的各向同性屏蔽值与实验化学位移一致。计算表明，N-氧化后的屏蔽张量的主成分的变化是相似的每种化合物。碳2、4、8和10在氮被氧化时在每种情况下被大部分屏蔽。对于C2、C4和C10，这种屏蔽是由于σ 11和/或σ22的大变化，表明π电子密度的变化。对于C8，大的屏蔽变化主要是由于σ33的变化，表明σ-电子密度的变化。通过对计算的抗疟药与未取代喹啉的~（13）C屏蔽张量分量的比较，发现阿莫地喹和氯喹在含氨基侧链的环上的π电子密度增加，奎宁在含甲氧基取代基的环上的π电子密度增加。
Chemical shift calculations are carried out for the quinoline carbons in 1,8-bis(2-isopropyl-4-quinolyl)naphthalene, 2-isopropylquinoline, amodiaquine, chloroquine, and quinine and theN-oxide of each compound. Ab initio calculations of the isotropic shielding values are in agreement with experimental chemical shifts. The calculations indicate that changes to the principal components of the shielding tensor upon N-oxidation are similar for each compound. Carbons 2, 4, 8, and 10 are largely shielded in each case as the nitrogen is oxidized. For C2, C4, and C10, this shielding is due to a large change in σ11and/or σ22, indicating a change in π-electron density. For C8, the large shielding change is due mainly to a change in σ33, indicating a change in σ-electron density. Upon examination and comparison of the calculated13C shielding tensor components in the antimalarial drugs versus those in unsubstituted quinolines, it is found that amodiaquine and chloroquine have increased π-electron density in the ring containing the amino side chain and quinine has increased π-electron density in the opposite ring, containing the methoxy substituent.