Reactions of trialkylgalliums with substituted hydrazines leading to the formation of rings and cages: X-ray structures of ((Pr2GaNHNMe2)-Pr-i)(2) and ((MeGaNHNBu)-Bu-t)(4)

The reaction of trialkylgalliums with substituted hydrazines forms simple L ewis acid-base adducts at room temperature. Subsequent thermolysis of these adducts leads to step by step alkane loss forming first dimeric rings, the n tetrameric cages. Thus the dimeric compounds [Me2GaNHNMe2](2), [Et2GaNHNM e2](2), [Me2GaNHNPh2](2), [Et2GaNHNPh2](2), [(Pr2GaNHNMe2)-Pr-i](2), and [( Me2GaNHNHBu)-Bu-t](2), have been synthesized. In addition, [(Pr2GaNHNMe2)-P r-i](2) has been characterized crystallographically. Although exclusively i n the anti conformation in the solid state, the dimers are fluxional in sol ution at room temperature. The fluxionalityl is examined in detail by NMR s pectroscopy. The tetrameric [(MeGaNHNBu)-Bu-t](4) has been isolated and cry stallographically characterized. It is shown to have a cage structure consi sting of two hexagonal and four pentagonal rings. (C) 1999 Elsevier Science S.A. All rights reserved.