Interactions of arylhydroxylamines and alkylaldoximes with a rhodium porphyrin
Interactions of arylhydroxylamines and alkylaldoximes with a rhodium porphyrin
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芳基羟胺和烷基醛肟与铑卟啉的相互作用
DOI：
10.1016/j.jinorgbio.2023.112337
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发表时间：
2023
影响因子：
3.9
通讯作者：
Richter-Addo, George B.
中科院分区：
文献类型：
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作者：
Londoño-Salazar, Jennifer;Ayala, Megan;Powell, Douglas R.;Shao, Yihan;Richter-Addo, George B.
血红素酶参与羟胺(RNHOH)和乙醛(RCH=NoH)化合物(Rh=H，烷基，芳基)的结合和代谢。本文报道了一种金属卟啉与芳基羟胺的配合物，即(TPP)Rh(PhNHOH)(C6H4Cl)(TPP=四苯基膦酸根二阴离子)的合成和X-射线晶体结构。晶体结构表明，除了PhNHOH与Rh的Ton-键外，羟胺-OH质子与卟啉N-原子之间还存在分子内氢键。密度泛函理论计算结果支持这一全球最小结构中分子内氢键的存在，自然键级分析表明，该氢键包含2.32千卡/摩尔的给体πN=C(卟啉)与受体σ*O-H(羟胺)的相互作用。虽然密度泛函计算预测了相关的缩醛肟络合物(TPP)Rh(RCH=NoH)(C6H4Cl)在其全局极小值结构中存在类似的分子内氢键相互作用，但(TPP)Rh(CH3(CH2)2CH=NoH)(C6H4Cl)配合物的X射线晶体结构与没有这种分子内氢键相互作用的局部(非全局)极小值构象是一致的。
Heme enzymes are involved in the binding and metabolism of hydroxylamine (RNHOH) and aldoxime (RCH=NOH) compounds (R = H, alkyl, aryl). We report the synthesis and X-ray crystal structure of a metalloporphyrin in complex with an arylhydroxylamine, namely that of (TPP)Rh(PhNHOH)(C6H4Cl) (TPP = tetraphenylpophryinato dianion). The crystal structure reveals, in addition toN-binding of PhNHOH to Rh, the presence of an intramolecular H-bond between the hydroxylamine –OHproton and a porphyrin N-atom. Results from density functional theory (DFT) calculations support the presence of this intramolecular H-bond in this global minimum structure, and a natural bond order (NBO) analysis reveals that this H-bond comprises a donor π N=C (porphyrin) to acceptor σ* O–H (hydroxylamine) interaction of 2.32 kcal/mol. While DFT calculations predict the presence of similar intramolecular H-bond interactions in the related aldoxime complexes (TPP)Rh(RCH=NOH)(C6H4Cl) in their global minima structures, the X-ray crystal structure obtained for the (TPP)Rh(CH3(CH2)2CH=NOH)(C6H4Cl) complex is consistent with the local (non-global) minima conformation that does not have this intramolecular H-bond interaction.