Quantum-chemical calculations for paramagnetic 13C NMR chemical shifts of iron-bound cyanide ions of iron porphyrins in ground and low-lying excited states containing ferric (dxy)2(dxz,yz)3 and (dxy)1(dxz,yz)4 configurations.
Quantum-chemical calculations for paramagnetic 13C NMR chemical shifts of iron-bound cyanide ions of iron porphyrins in ground and low-lying excited states containing ferric (dxy)2(dxz,yz)3 and (dxy)1(dxz,yz)4 configurations.
复制标题
含铁 (dxy)2(dxz,yz)3 和 (dxy)1(dxz,yz)4 的基态和低激发态铁卟啉的铁结合氰化物离子的顺磁 13C NMR 化学位移的量子化学计算
DOI：
--
复制
发表时间：
2004
影响因子：
15
通讯作者：
M. Hada
中科院分区：
文献类型：
--
作者：
M. Hada
对含铁（dxy）2(dxz,yz)3和（dxy）1(dxz,yz)4两种构型的二（氰）和氰-咪唑铁（III）卟啉进行了精确的量子化学计算。反式配体效应对铁结合13CN-的顺磁13C核磁共振化学位移的影响得到了很好的再现。此外，在具有卷曲卟啉环的双（氰化物）（中-四乙基）Fe（III）卟啉中，（dxy）1(dxz,yz)4构型包含在基态中，而另一种（dxy）2(dxz,yz)3构型位于与基态能量接近的位置。在（dxy）1(dxz,yz)4构型中，卟啉环的褶皱极大地影响铁结合CN的13C化学位移，而在（dxy）2(dxz,yz)3构型中则没有影响。
Accurate quantum-chemical calculations were carried out for bis(cyanide) and cyanide-imidazole Fe(III) porphyrins in the ground and low-lying excited states including both the ferric (dxy)2(dxz,yz)3 and (dxy)1(dxz,yz)4 configurations. The trans-ligand effect on the paramagnetic 13C NMR chemical shifts of the iron-bound 13CN- was well reproduced by the present calculations. Further, in bis(cyanide)(meso-tetraethyl) Fe(III) porphyrin, which has a ruffled porphyrin ring, the (dxy)1(dxz,yz)4 configuration is included in the ground state, and the alternative (dxy)2(dxz,yz)3 configuration is located closely in energy to the ground state. Ruffling of porphyrin rings extremely affects the 13C chemical shift of iron-bound CN in the (dxy)1(dxz,yz)4 configuration but not in the (dxy)2(dxz,yz)3 configuration.