ELECTRON-PARAMAGNETIC RESONANCE STUDY OF THE REACTION OF GROUND-STATE AL ATOMS WITH NH3 IN A ROTATING CRYOSTAT

An electron paramagnetic resonance spectroscopic study of the reaction of ground-state Al atoms with NH3 in adamantane at 77 K on a rotating cryostat has demonstrated the formation of three mononuclear Al-NH3 complexes, Al(NH3)4 (A), HAlNH2 (B), and Al(NH3)2 (C). These species have the following magnetic parameters: a(Al) = 786.3 +/- 0.22 MHz, a(N) = 23 +/- 0.08 MHz, and g = 1.9997 +/- 0.0001 for Al(NH3)4, a(Al) = 922.5 +/- 0.41 MHz, a(H) = 228.7 +/- 2.00 MHz, a(N) = 27 +/- 2.0 MHz, a(H)(1) = 27 +/- 2.0 MHz, and g = 2.0003 +/- 0.0002 for HAlNH2, and a parallel-to(Al) = 131.5 MHz, a perpendicular-to(Al) = ca. 20 MHz, and g parallel-to = g perpendicular-to = 1.999 for Al(NH3)2. HAlOH (D) is also formed in this system from adventitious H2O and has the parameters a(Al) = 911.3 +/- 1.06 MHz, a(H) = 286.4 +/- 3.7 MHz, and g = 1.9998 +/- 0.0004.