Synthesis and structure of adduct stabilized Group III metal transition metal carbonyl complexes: new examples for FeGa, FeIn, WAl, CrAl and CrGa bonds

The carbonylmetallate dianions Fe(CO)42−, Cr(CO)52− and W(CO)52− react in THF with the Group III halogenides EX3 (E=Al, Ga, In; X=Cl, Br, I) and X2ER (E=Al, Ga; X=Cl R=Me, tBu). After the addition of chelating Lewis base [tmpda, pmdeta (tmpda=N,N,N′,N′-tetramethylpropylenediamine, pmdeta=N,N,N′,N′′,N′′-pentamethyldiethylenetriamine)] and solvent exchange with dichloromethane, the primary products undergo a second salt elimination reaction, yielding the following complexes: [(CO)4FeGa(X)(tmpda)] (X=I, Me) (1 and 2), [(CO)nMAl(X)(tmpda)] (M=Fe, W; n=4, 5; X=Cl, tBu) (3 and 4), [(CO)4FeIn(Br)(tmpda)] (5), [(CO)5CrE(Cl)(tmpda)] (E=Al, Ga) (6 and 7), [(CO)4FeIn(Br)(pmdeta)] (8) and cationic complex [(CO)4FeGa(pmdeta)]+I− (9). The new compounds were fully characterized by means of elemental analysis, IR and NMR spectroscopy. The structures of [(CO)4FeGa(Me)(tmpda)] (1), [(CO)4FeGa(I)(tmpda)] (2), [(CO)5WAl(tBu)(tmpda)] (4), [(CO)4FeIn(Br)(tmpda)] (5), [(CO)5CrAl(Cl)(tmpda)] (6), [(CO)4FeIn(Br)(pmdeta)] (8) and [(CO)4FeGa(pmdeta)]+I− (9) have been studied by single-crystal X-ray diffraction. Compound 1: orthorhombic space group Pnma, Z=4. a=13.240(16), b=11.623(14), c=10.316(13) Å, α=90, β=90, γ=90°, V=1588(3) Å3, and R=0.0364 (Rw=0.1037). Compound 2: triclinic space group P1̄, Z=2. a=8.2059(13), b=8.2783(13), c=14.348(2) Å, α=75.155(3), β=83.953(3), γ=62.117(3)°, V=832.7(2) Å3, and R=0.0346 (Rw=0.0828). Compound 4: monoclinic space group P21/n, Z=4. a=8.780(5), b=14.284(4), c=16.339(5) Å, α=90, β=96.91(2), γ=90°, V=2034.2(14) Å3, and R=0.0577 (Rw=0.1303). Compound 5: orthorhombic space group P212121, Z=4. a=7.534(3), b=14.978(9), c=15.192(9) Å, α=90, β=90, γ=90°, V=1714.4(16) Å3, and R=0.0409 (Rw=0.1363). Compound 6: monoclinic space group C2/c, Z=10. a=26.458(5), b=8.998(5), c=15.567(3) Å, α=90, β=115.83(5), γ=90°, V=3336(2) Å3, and R=0.0343 (Rw=0.0650). Compound 8: monoclinic space group C2/c, Z=16. a=30.717(7), b=8.746(2), c=28.677(6) Å, α=90, β=94.99(5), γ=90°, V=7675(3) Å3, and R=0.0526 (Rw=0.1591). Compound 9: monoclinic space group P21/c, Z=4. a=14.157(1), b=24.395(2), c=13.547(1) Å, α=90, β=97.86(2), γ=90°, V=4633.9(8) Å3, and R=0.0522 (Rw=0.1334).