FOURIER TRANSFORM MICROWAVE SPECTROSCOPY OF CuCCH (X$^{1}\Sigma^+$)

Abstract

The rotational spectrum of CuCCH (X$^{1}\Sigma^+$) has been measured using Fourier transform microwave (FTMW) spectroscopy. This work is the first gas-phase spectroscopic study of this molecule. The species was produced using Discharge Assisted Laser Ablation Spectroscopy (DALAS) in a supersonic jet expansion with HCCH as the precursor molecule. Four rotational transitions (J = 1 $\rightarrow$ 0, 2 $\rightarrow$ 1, 3 $\rightarrow$ 2, and 4 $\rightarrow$ 3) have been measured for the $^{63}$CuCCH and $^{65}$CuCCH isotopologues in the range 8-33 GHz. Copper quadrupole splittings have been resolved in both species. The data have been analyzed, and rotational and hyperfine constants determined. Measurements of the carbon-13 and deuterium isotopologues are currently being conducted to establish a precise structure for CuCCH. Compounds of the form CuCCR play an important role in organic synthesis.