摘要 : The AlND3 complex was studied in a molecular beam by resonant one-color two-photon and two-color two-photon photoionization techniques with a resolution of 0.3 cm(-1). Six progressions of bands were observed in the 18 100-26 200 c... 展开 The AlND3 complex was studied in a molecular beam by resonant one-color two-photon and two-color two-photon photoionization techniques with a resolution of 0.3 cm(-1). Six progressions of bands were observed in the 18 100-26 200 cm(-1) (381-552 nm) region. One progression (omega(e) = 316 +/- 0.8 cm(-1)) was assigned to the Al-ND3 stretch (nu(3)(')) in the (B) over tilde(2)A(1) state correlating with the 3s S-2 term of Al. The origin of the (B) over tilde(2)A(1)-(X) over tilde(2)E(1/2) system was found at 18 532.5 +/- 0.7 cm(-1). The second (omega(e) = 428 +/- 2 cm(-1)) and third (omega(e) = 594 +/- 12 cm(-1)) progressions were assigned to the Al-ND3 stretch (nu(3)(')) and the bend (nu(6)(')) in the (C) over tilde(2)E state correlating with the 3d D-2 term of Al. The origin of the (C) over tilde(2)E-(X) over tilde(2)E(1/2) system was found at 21 185 +/- 5 cm(-1). Assignments of the other three progressions with origins and harmonic wave numbers of 22 667 +/- 2 and 358 +/- 2 cm(-1); 24 382 +/- 10 and 432 +/- 10 cm(-1); and similar to 21 871 and similar to 1050 cm(-1) remain uncertain. The spin-orbit splitting of the (X) over tilde(2)E ground state was determined to be 55.8 +/- 0.7 cm(-1). Several Rydberg series converging to the upsilon(3)(+) = 1, 2, and 3 levels of the ground state of the AlND3+ ion were observed. The ionization potential of the AlND3 complex was measured to be 39 710 +/- 2 cm(-1). The nu(3)(+) fundamental in the ground state of the AlND3+ ion was found to be 325 +/- 5 cm(-1). To aid the interpretation of our spectra, ab initio optimized structures and vibrational wave numbers for the ground states of various isotopomers of AlNH3 and AlNH3+ were calculated. Also, Al-NH3 potential curves for several low-lying excited states were calculated. In addition, the ionization potential of the AlNH3 isotopomer was measured by the one-photon photoionization efficiency technique. The value of 39 760 +/- 10 cm(-1) is an improvement on that previously reported by Di Palma [Chem. Phys. Lett. 284, 184 (1998)], which was 180 cm(-1) smaller. (C) 2000 American Institute of Physics. [S0021-9606(00)00304-4]. [References: 20] 收起