Anion Photoelectron Spectroscopy and Quantum Chemical Calculations of Bimetallic Oxide Clusters YCu 2 O n -/0 ( n = 2-5).

The structural and electronic properties of bimetallic oxide clusters, YCu 2 O n - and YCu 2 O n ( n = 2-5), are investigated using anion photoelectron spectroscopy and density functional theory calculations. The experimental vertical detachment energies of YCu 2 O 2 - , YCu 2 O 3 - , YCu 2 O 4 - , and YCu 2 O 5 - were measured to be 1.59, 1.76, 3.85, and 3.78 eV, respectively. Vibrationally resolved photoelectron spectra have been obtained for YCu 2 O 2 - , with a spacing of 726 ± 80 cm -1 assigned to the Y-O stretching vibrational mode. It is found that YCu 2 O 2 - and YCu 2 O 2 have C 2v symmetric planar five-membered ring structures. YCu 2 O 3 - and YCu 2 O 3 have C 2v symmetric planar six-membered ring structures. The most stable structure of YCu 2 O 4 - is a quasi-planar structure which can be viewed as one O atom interacting with the Y atom of the YCu 2 O 3 six-membered ring, while the most stable structure of YCu 2 O 4 is a planar seven-membered ring. YCu 2 O 5 - and YCu 2 O 5 have nonplanar structures, which can be viewed as an O 2 unit interacting with the Y atom of the YCu 2 O 3 six-membered ring. In YCu 2 O 3,4,5 -/0 , the Y-O and Cu-O bonds are dominant, while the Y-Cu and Cu-Cu interactions are weak.