Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany.
Angew Chem Int Ed Engl. 2023 Jun 5;62(23):e202300761. doi: 10.1002/anie.202300761. Epub 2023 Apr 18.
The interstellar candidate phosphorus mononitride PN, a metastable species, was generated through high-vacuum flash pyrolysis of (o-phenyldioxyl)phosphinoazide in cryogenic matrices. Although the PN stretching band was not directly detected because of its low infrared intensity and possible overlaps with other strong bands, o-benzoquinone, carbon monoxide, and cyclopentadienone as additional fragmentation products were clearly identified. Moreover, an elusive o-benzoquinone-PN complex formed when (o-phenyldioxyl)phosphinoazide was exposed to UV irradiation at λ=254 nm. Its recombination to (o-phenyldioxyl)-λ -phosphinonitrile was observed upon irradiation with the light at λ=523 nm, which demonstrates for the first time the reactivity of PN towards an organic molecule. Energy profile computations at the B3LYP/def2-TZVP density functional theory level reveal a concerted mechanism. To provide further evidence, UV/Vis spectra of the precursor and the irradiation products were recorded and agree well with time-dependent DFT computations.
磷单氮化物 PN 是一种亚稳星际候选物，通过低温基质中（邻苯二氧膦）叠氮膦的高真空闪蒸热解来生成。尽管由于其红外强度低且可能与其他强带重叠，因此未直接检测到 PN 伸缩带，但作为额外的碎裂产物，邻苯醌、一氧化碳和环戊二烯酮被清楚地识别出来。此外，当（邻苯二氧膦）叠氮膦在 λ=254nm 的紫外线照射下时，会形成一种难以捉摸的邻苯醌-PN 配合物。当用 λ=523nm 的光照射时，观察到其重新组合为（邻苯二氧膦）-λ-磷腈，这首次证明了 PN 对有机分子的反应性。在 B3LYP/def2-TZVP 密度泛函理论水平上的能量势垒计算表明这是一个协同机制。为了提供进一步的证据，记录了前体和辐照产物的紫外/可见光谱，并与时间相关的 DFT 计算吻合得很好。
