Temperature induced single-crystal to single-crystal transformation of uranium azide complexes.

The monomeric and dimeric uranium azide complexes {[(CH 3 ) 2 NCH 2 CH 2 NP i Pr 2 ] 2 U(N 3 ) 2 } (2) and {[(CH 3 ) 2 NCH 2 CH 2 NP i Pr 2 ] 2 U(N 3 ) 2 } 2 (3) were synthesized by treating complex 1 with NaN 3 at 60 and -20 °C, respectively. A temperature-induced single-crystal to single-crystal transformation of 3 to 2 was observed. The reduction of either 2 or 3 with KC 8 yields a uranium nitride complex {[(CH 3 ) 2 NCH 2 CH 2 NP i Pr 2 ] 4 U 2 (μ-N) 2 } (4).