Observation and assignment of a high-resolution FTIR-spectrum of T216O, DT16O and HT16O in the range of 4300 to 4700cm−1

Abstract

In the range of $4300$ to $\text{4700}\text{cm}{}^{\mathrm{-1}}$, we present analysis of the $2{\nu }_1$, $2{\nu }_2$+${\nu }_3$ and ${\nu }_1$+${\nu }_3$ bands of T${}_2^{16}$O, the $2{\nu }_1$ and ${\nu }_1$+$2{\nu }_2$ of DT${}^{16}$O and the $2{\nu }_1$ of HT${}^{16}$O. The analysed high-resolution spectrum has been obtained from a Bruker IFS 125HR Fourier-transform spectrometer with a resolution of $\text{0.025}\text{cm}{}^{\mathrm{-1}}$ using an optical cell with an activity of $\text{10}\text{GBq}$. For the in total 2436 lines an individual positional uncertainty of up to $\text{3.4}\times \text{10}{}^{\mathrm{-5}}\text{cm}{}^{\mathrm{-1}}$ and a systematic uncertainty of $\text{7.5}\times \text{10}{}^{\mathrm{-4}}\text{cm}{}^{\mathrm{-1}}$ could be achieved. Four of the six bands have been analysed for the first time, the ${\nu }_1$+${\nu }_3$ band of T${}_2^{16}$O and the $2{\nu }_1$ of HT${}^{16}$O have been analysed in previous works of our group. These datasets are extended by 527 new lines and a cross check is confirming the consistency between both works. A comparison of the assigned line positions to the variationally calculated predictions from the Tomsk database agrees with previous findings indicating that band-specific shifts and shifts depending on the rotational quantum numbers are observed leading to an overall difference of up to $\text{0.3}\text{cm}{}^{\mathrm{-1}}$.