HIGH-RESOLUTION FOURIER-TRANSFORM EMISSION-SPECTROSCOPY OF THE C-1-SIGMA(-X(1)SIGMA(+) AND E(3)PHI-A(3)DELTA SYSTEMS OF YD())

High-resolution electronic emission spectra of YD have been recorded i n the 690 nm to 3 mu m spectral region using a Fourier transform spect rometer. YD molecules were excited in a yttrium hollow cathode lamp op erated with neon gas and a trace of deuterium. The observed bands have been classified into two different electronic transitions: C-1 Sigma( +)-X(1) Sigma(+) and e(3) Phi-a(3) Delta. The rotational analysis of t he 0-0, 1-1, 2-2, 0-1, 1-2, and 2-3 bands of the C-1 Sigma(+)-X(1) Sig ma(+) system provides the following set of equilibrium molecular const ants for the ground state: omega(e) = 1089.1182(81) cm(-1), omega(e)x( e) = 9.8459(38) cm(-1), omega(e)y(e) = 0.0144(8) cm(-1) B-c = 2.320192 (10) cm(-1), alpha(e) = 0.032960(6) cm(-1), and r(e) = 1.920404(4) Ang strom. Three bands observed in the red region with origins at 11 398.0 507(14), 11 523.0523(13), and 11 611.6396(7) cm(-1) have been assigned as the 0-0 bands of the (3) Phi(2)-(3) Delta(1), (3) Phi(3)-(3) Delta (2), and (3) Phi(4)-(3) Delta(3) subbands, respectively, of a new e(3) Phi-a(3) Delta electronic transition. Several additional bands, all d egraded toward higher wavenumbers, have been identified in the 7800-85 00 cm(-1) region. The very weak intensity of these bands limited the i nformation which could be extracted from them. (C) 1995 Academic Press , Inc.