Unusual Quartet‐Doublet Phosphorescence from the Phosphaethynyl Radical, CP

Abstract

We report the first detection of phosphorescence from the phosphaethynyl radical. This rare instance of quartet-doublet emission, studied here in solid argon, is presumably promoted by efficient intersystem crossing from the originally photoexcited doublet (B 2 Σ + ) to the adjacent second quartet state, 1 4 Δ. Vibronic progressions were traced for the a 4 Σ + -X 2 Σ + and a 4 Σ + -A 2 П i systems from their origins up to (v' = 0)!(v'' = 5) and (v' = 0)!(v'' = 2) bands, respectively. The measured phosphorescence lifetime is 108 � 3 ms.

Hydrogen-Bonded π Complexes between Phosphaethyne and Hydrogen Chloride

“…As the simplest organophosphorus compound, HCP is a prebiotic species that has been detected in the interstellar medium (ISM) such as the carbon-rich source CRL 2688 and the asymptotic giant branch (AGB) star envelope IRC + 10216, − and it is proposed as a main phosphorus carrier in the ISM through hydrogenation reactions of the more reactive phosphaethynyl radical (CP) , on the surface of icy grains. Quite recently, the formation of CP through photolysis HCP in solid Ar at 6 K has been observed …”

“…Quite recently, the formation of CP through photolysis HCP in solid Ar at 6 K has been observed. 14 Chemically, HCP is very reactive, and it can react with hydrogen chloride (HCl) through successive addition to the unsaturated C�P bond by the stepwise formation of 1chlorophosphaethene (CH 2 PCl) and dichloromethylphosphine (CH 3 PCl 2 ). 3 The reverse HCl-elimination reactions are also feasible under pyrolytic conditions, which has been used as a practical method for the gas-phase synthesis of simple phosphaalkynes such as FCP 15 and PhCP.…”

Electronically Excited States of Free Radicals

“…Phosphoresce Do ← Q1 was observed for phosphaethynyl radical in the solid argon [13]. The scheme of electronic levels for this radical follows Figure 1, and the lifetime of the emission was ~0.1 s [13].…”

Electronically Excited States of Free Radicals

“…Phosphoresce D 0 ← Q 1 was observed for phosphaethynyl radicals in solid argon [13]. The scheme of the electronic levels for this radical follows Figure 1, and the lifetime of the emission is ~0.1 s [13].…”