Syntheses and Reactions of Derivatives of (Pyrrolylaldiminato)germanium(II) and -Aluminum(III)

(Pyrrolylaldiminato)­germanium­(II) chloride, LGeCl (1), was prepared by reacting LLi (L = 2-(ArNCH)-5-tBuC₄H₂N; Ar = 2,6-iPr₂C₆H₃) with 1 equiv of GeCl₂·(dioxane). Treatment of LGeCl (1) with KOtBu or LiN­(H)Ar yielded LGeR (R = OtBu (2), N­(H)Ar (3)) by halide metathesis. (Pyrrolylaldiminato)­methylaluminum chloride, LAlMe­(Cl) (4), was obtained from the reaction of LLi and MeAlCl₂ or by treating LH with Me₂AlCl in toluene. Treatment of LH with Me₂AlCl or AlCl₃ in Et₂O at −18 °C resulted in the 1:1 adducts LH·AlMe₂Cl (5) and LH·AlCl₃ (5′), respectively. Further reaction of 4 with 2 equiv of LiNEt₂ led to the insertion of the NEt₂ group into the CN bond together with the elimination of LiCl, to afford L′(NEt₂)­AlMe­(NEt₂)­Li­(THF) (6). Similarly, treatment of 4 with 2 equiv of LiPPh₂(THF)₂ gave L′(PPh₂)­AlMe­(OC₄H₈-PPh₂)­Li­(THF)₂ (7) accompanied by ring opening of THF. Single-crystal X-ray structure determinations revealed that 3 and 4 each contained enantiomeric pairs, while 6 and 7 each adopted a single enantiomer.