The reactivitie
s of Me
2AlH withP(SiMe
3)
3 and of Me
3M (M = Al,Ga, In) and Bu
i2AlHwith P(SiMe
3)
3 andHP(SiMe
3)
2 were monitored withmultinuclear NMR to determine thetrend for adduct formation and e
stabli
sh the role that the Me andBu
i moietie
s and M playin influencing the nature of the po
ssible 1,2-elimination product.1:1 adduct
s were obtainedin the Me
3M/P(SiMe
3)
3 sy
stem
s withno tendency toward room-temperature, 1,2-eliminationreactivity. Thermoly
si
s at 100
s/entitie
s/deg.gif">C gave the following order ofreactivity for SiMe
4elimination:Me
3In·P(SiMe
3)
3 >Me
3Ga·P(SiMe
3)
3 >>Me
3Al·P(SiMe
3)
3.With the Me
3M/HP(SiMe
3)
2 sy
stem
s, only Me
3Algave an i
solable adduct, which eliminated CH
4 uponheatingto form[Me
2AlP(SiMe
3)
2]
2.Although NMR
spectral data indicated adduct formation intheMe
3Ga and Me
3In
sy
stem
s, the
seunderwent CH
4 elimination to yield the re
spective[Me
2MP(SiMe
3)
2]
2 specie
s. Thevariable-temperature, multinuclear NMR
study of theMe
2AlH/P(SiMe
3)
3 sy
stem indicated adduct formation at-90
s/entitie
s/deg.gif">C and
sub
sequent conver
sion to cyc
licoligomeric[Me
2AlP(SiMe
3)
2]
n[Me
2AlH]
mspecie
s at -80
s/entitie
s/deg.gif">C that ultimately produced[Me
2AlP(SiMe
3)
2]
2. Thereactivity of Bu
i2AlH towardP(SiMe
3)
3 andHP(SiMe
3)
2 i
s much
slowerthen that of Me
2AlH. In theBu
i2AlH/HP(SiMe
3)
2sy
stem, H
2 elimination i
s favored and[Bu
i2AlP(SiMe
3)
2]
2 andBu
i2AlP(SiMe
2)
2·Bu
i2AlP(H)SiMe
3are formed. An X-ray
structure analy
si
sof[Bu
i2AlP(SiMe
3)
2]
2e
stabli
she
s the planarity of the (AlP)
2 core.