The Simplest, Isolable, Alkynyl Isocyanate HC≡CNCO: Synthesis and Characterization

Yuanyuan Qin; Bo Lu; Guntram Rauhut; Manfred Hagedorn; Klaus Banert; Chao Song; Xianxu Chu; Lina Wang; Xiaoqing Zeng

doi:10.1002/anie.201911102

The Simplest, Isolable, Alkynyl Isocyanate HC≡CNCO: Synthesis and Characterization

Angew Chem Int Ed Engl. 2019 Nov 25;58(48):17277-17281. doi: 10.1002/anie.201911102. Epub 2019 Oct 15.

Authors

Yuanyuan Qin¹, Bo Lu¹, Guntram Rauhut², Manfred Hagedorn³, Klaus Banert³, Chao Song¹, Xianxu Chu¹, Lina Wang⁴, Xiaoqing Zeng^{1

4}

Affiliations

¹ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
² Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany.
³ Chemnitz University of Technology, Organic Chemistry, Strasse der Nationen 62, Chemnitz, 09111, Germany.
⁴ Department of Chemistry, Fudan University, Shanghai, 200433, China.

PMID: 31553514
DOI: 10.1002/anie.201911102

Abstract

Alkynyl isocyanates have been postulated as highly reactive intermediates in synthetic chemistry. Herein, the parent molecule HC≡CNCO is isolated for the first time. In sharp contrast to the previously reported short lifetime (ca. 15 s) at room temperature, we found that HC≡CNCO has a lifetime of 55 h in the gas phase (2 mbar, 300 K) with a melting point of -79.5 °C and vaporization enthalpy (ΔH_vap ) of 23.1(1) kJ mol^-1 . Apart from the IR (gas, solid, and matrix), ¹ H and ¹³ C NMR, and UV/Vis spectroscopic characterization, its photoisomerization with a acylnitrene HC≡CC(O)N and cyanoketene NCC(H)CO has been observed.

Keywords: alkynes; heterocumulenes; isocyanates; isomers; photochemistry.

Abstract

Grants and funding