ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We report absorption, laser fluorescence, and Raman spectra for Re2 in an argon matrix prepared by the mass-selected ion deposition technique. The dirhenium absorption spectrum consists of seven band systems (A–G) extending from the near infrared into the ultraviolet region. For the A system (a simple vibrational progression), we find T0=10 817(1) cm−1, ωe=317.1(5) cm−1 and ωexe=1.0(1) cm−1. A Franck–Condon analysis of the A system intensities predicts that this state has a smaller equilibrium internuclear distance than the ground state (Δre=−0.073 A(ring)), in violation of Badger's rule. The B system starts at 13 250 cm−1 and consists of four overlapping (and possibly perturbed) subsystems, whose average vibrational spacing is 270(11) cm−1. The C, D, E, and F systems (vibrational spacings in parentheses) are centered at 22 300 cm−1 (210 cm−1), 24 500 cm−1 (195 cm−1), 29 150 cm−1 (175 cm−1), and 32 900 cm−1 (160 cm−1), respectively. Weak fluorescence spectra, obtained upon laser excitation into the A system, were characterized by vibrational progressions to the dimer ground (X) state and to a low lying (X') state for which T0=357.6(5) cm−1 and ωe=332.3(2) cm−1. Raman and fluorescence progressions to the ground state were observed when the B system was excited. These data give ωe=337.9(49) cm−1 for the dimer ground state in good agreement with measurements from photodetachment spectra [J. Am. Chem. Soc. 108, 178 (1986)]. We propose likely assignments for the low lying electronic states of Re2 and discuss our results in terms of the bonding in the other group VIIB dimers, Mn2 and Tc2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.468092
