Microwave Spectrum and Molecular Structure of Methyl Cyanate

✍ Scribed by T. Sakaizumi; K. Sekishita; K. Furuya; Y. Tetsuda; K. Kaneko; O. Ohashi; I. Yamaguchi

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 362 KB
• Volume: 161
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1993.1220

✦ Synopsis

In order to determine the complete (r_{s}) structure of methyl cyanate, the microwave spectra of ({ }^{13} \mathrm{CH}{3} \mathrm{OCN}, \mathrm{CH}{3}{ }^{18} \mathrm{OCN}, \mathrm{CH}{3} \mathrm{O}^{13} \mathrm{CN}), sym- (\mathrm{CH}{2} \mathrm{DOCN}), and asym- (\mathrm{CH}{2} \mathrm{DOCN}) have been observed in the frequency range from 7.5 to (50.0 \mathrm{GHz}). From these data together with the already reported molecular constants of normal and ({ }^{15} \mathrm{~N}) isotopic species, the following structural parameters [bond lengths in (\AA(1 \AA=0.1 \mathrm{~nm})) and angles in degrees] are obtained: (r\left(C{1}-\mathbf{H}{1}\right)=1.074(12)), (r\left(\mathrm{C}{1}-\mathrm{H}{2}\right)=1.075(25), r\left(\mathrm{C}{1}-\mathrm{O}\right)=1.455(1), r\left(\mathrm{O}-\mathrm{C}{2}\right)=1.302(3), r\left(\mathrm{C}{2}-\mathrm{N}\right)=1.146(3)), (\left\langle\mathrm{H}{1}-\mathrm{C}{1}-\mathrm{H}{2}=110.4(22),\left\langle\mathrm{H}{2}-\mathrm{C}{1}-\mathrm{H}{2}=110.7(35),\left\langle\mathrm{H}{1}-\mathrm{C}{1}-\mathrm{O}=106.5(11)\right.\right.\right.), (\left\langle\mathrm{H}{2}-\mathrm{C}{1}-\mathrm{O}=109.4(14),\left\langle\mathrm{C}{1}-\mathrm{O}-\mathrm{C}{2}=113.8(3)\right.\right.), and (\left\langle\mathrm{O}-\mathrm{C}{2}-\mathrm{N}=178.4(6)\right.). The (\mathrm{r}{\mathrm{s}}) structure of methyl cyanate indicates that the bond length of (r\left(\mathrm{O}-\mathrm{C}{2}\right)) is much shorter than that of (r\left(O-C{1}\right)) and that the (\mathrm{OCN}) chain is slightly bent. The obtained structural parameters were very similar to those of methoxyethyne (\left(\mathrm{CH}_{3} \mathrm{OCCH}\right)), which is an isoelectric molecule of methyl cyanate. (c) 1993 Academic Press, Inc.