title: Analysis of uranium azide and nitride complexes by atmospheric pressure chemical ionization mass spectrometry.
abstract: Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) has been used to characterize the air-sensitive paramagnetic organouranium azide and nitride complexes [(C5Me5)2UN3(mu-N3)]3 and [(C5Me5)U(mu-I)2]3N, respectively. The trimetallic complex [(C5Me5)U(mu-I)2]3E had been identified by X-ray crystallography, but the data did not definitively identify E as N3- versus O2- or (OH)-, a common problem in heavy-element nitride complexes involving metals with variable oxidation states. A comparison of the 250 degrees C APCI-MS spectra of products made from NaN3 and Na15NNN showed mixed [M]+ and [M + H]+ envelopes at expected ion intensities for the 14N and 15N isotopomers. A compilation of U-C(C5Me5) and U-I bond distance data for U3+ and U4+ is also reported that shows that the ranges for the two oxidation states have significant overlap.
authors: Department of Chemistry, University of California, Irvine, California 92697-2025, USA. wevans@uci.edu
authors: William J
authors: WJ
authors: Evans
authors: Kevin A
authors: KA
authors: Miller
authors: Joseph W
authors: JW
authors: Ziller
authors: John
authors: J
authors: Greaves