2 Homometallic Alkoxides

MgCl2 C 2Ti⊲OEt⊳4
MCl2 C 2Zr⊲OPr i ⊳4
Heterometallic Alkoxides 195
n-heptane
! [MgfTi2⊲OEt⊳8Clg⊲ -Cl⊳]2 146
toluene
! [MfZr2⊲OPr i ⊳8Clg⊲ -Cl⊳]2
⊲3.65⊳
⊲3.66⊳
where M D Be, Mg, Zn, Sn(II). 147
All the derivatives obtained in the above reactions are white crystalline solids,
dimeric in solution (benzene) except the beryllium derivative which also dimerizes
on ageing. The beryllium product was distilled at ¾190 Ž C under 0.05 mm pressure
whereas under these conditions the magnesium derivative yielded a sublimate corresponding
in analysis to Mg4Zr6Cl3⊲OPr i ⊳23O3. All these products appear to be chloride
bridged, which is corroborated by the crystal structure of the Mg–Ti product. 146
Chloride alkoxides of Be, Mg, Zn and Sn(II) with Nb(V) have also been synthesized
by a similar series of reactions (Eqs 3.67 and 3.68): 148
MCl2 C Nb⊲OPr i ⊳5
MCl2 C 2Nb⊲OPr i ⊳5
benzene
1
! 2
68 hr⊲stir⊳
[fM⊲Nb⊲OPri⊳5Cl⊳g⊲ -Cl⊳]2
!
68 hr⊲stir⊳
⊲3.67⊳
[MfNb⊲OPr i ⊳6Clg2] ⊲3.68⊳
2.3 Synthesis of Higher Heterometallic Alkoxides and Allied Derivatives
Starting with bimetallic chloride (iodide) alkoxides synthesized by the general reaction
of Eq. (3.69):
MClx C yKL ! MClx yLy C yKCl # ⊲3.69⊳
where y < x, a variety of heterotrimetallic and -tetrametallic alkoxides of Be, 7 lanthanons;
17,149 Zn and Cd; 150,151 Sn(II) and(IV); 152,153 Mn(II); 101 Fe(II); 109 Fe(III); 9,154,155
Co(II); 156 Ni(II); 157 Cu(II) 8,158 and Mg 159 can be synthesized as illustrated in a few
representative cases by Eqs (3.70)–(3.79):
fAl⊲OPr i ⊳4gBeCl C KfZr2⊲OPr i ⊳9g –KCl
!fAl⊲OPr i ⊳4gBefZr2⊲OPr i ⊳9g ⊲3.70⊳
fZr2⊲OPr i ⊳9gMCl C KfAl⊲OPr i ⊳4g –KCl
!fZr2⊲OPr i ⊳9gMfAl⊲OPr i ⊳4g ⊲3.71⊳
where M D Mn(II), Fe(II), Co(II), Ni(II).
fZr2⊲OPr i ⊳9gNiCl C KGa⊲OPr i ⊳4
fZr2⊲OPr i ⊳9gMCl C KTa⊲OPr i ⊳6
where M D Fe(II), Co(II).
fNb⊲OPr i ⊳6gCoCl C KAl⊲OPr i ⊳4
–KCl
!fZr2⊲OPr i ⊳9gNifGa⊲OPr i ⊳4g ⊲3.72⊳
–KCl
!fZr2⊲OPr i ⊳9gMfTa⊲OPr i ⊳6g ⊲3.73⊳
–KCl
!fNb⊲OPr i ⊳6gCofAl⊲OPr i ⊳4g ⊲3.74⊳