We have prepared crystals of [Fe(TTP)(NO)] (TTP = tetratolylporphyrin), a five-coordinate nitrosyl complex and determined its crystal and molecular structure at two temperatures. The crystal structure at 100 K reveals two independent molecules in the asymmetric unit of the structure. One molecule is completely ordered and the second molecule has a moderately disordered nitrosyl ligand. Both molecules show similar structural features: a substantial off-axis tilt of the Fe–N(NO) bond and an asymmetry of the equatorial Fe–Np bonds that is correlated with the tilt. The axial Fe–N(NO) bond distances are 1.7230 (9) and 1.7210 (10) Å; the Fe–N–O bond angles are 141.62 (8) and 140.04 (10)∘. Determination of the structure at ambient temperature (293 K) showed an unexpected phase change, a crystal structure with one molecule per asymmetric unit containing the superposition of the two molecules at lower temperature. However, there was an increase in the NO disorder.

中文翻译：

---

温度对结构的影响：五配位（亚硝基）（四甲苯基卟啉）铁（II）

我们制备了 [Fe(TTP)(NO)] (TTP = 四甲苯基卟啉) 的晶体，一种五配位亚硝基配合物，并在两个温度下确定了其晶体和分子结构。100 K 的晶体结构揭示了结构的不对称单元中的两个独立分子。一个分子是完全有序的，第二个分子具有适度无序的亚硝基配体。两种分子都表现出相似的结构特征：Fe-N(NO) 键的显着离轴倾斜和赤道 Fe-N 的不对称p与倾斜度相关的键。轴向 Fe-N(NO) 键距离为 1.7230 (9) 和 1.7210 (10) Å；Fe-N-O 键角为 141.62 (8) 和 140.04 (10)∘. 在环境温度 (293 K) 下对结构的测定显示出意想不到的相变，即每个不对称单元一个分子的晶体结构，其中包含两个分子在较低温度下的叠加。然而，NO 紊乱有所增加。